JP5612370B2 - Article inspection apparatus and article inspection method - Google Patents

Description

  The present invention relates to a technique for inspecting the appearance of an article, and in particular, while the article is conveyed by the conveyance means, the appearance of the article is at least detected by imaging means arranged on the upstream side, the downstream side, and the upper side in the conveyance direction. The present invention relates to imaging and inspection technology.

  Conventionally, in order to inspect the hue, damage, size, shape, decay, etc. of crops, the appearance of crops is imaged by an imaging means, and compared with a reference image, hue, damage, size, An inspection apparatus that collects and inspects information on crops such as shape and rot is known. Such an inspection apparatus is used as an appearance inspection means in a sorting apparatus that sorts agricultural products by grade.

  In Patent Document 1, as an inspection apparatus, a plurality of imaging cameras are provided on both sides of a conveyance path for conveying a crop so as to be able to image the crop from obliquely front and back, and further from the top and bottom of the conveyance path. Imaging the upper and lower peripheral surfaces is disclosed. In general, each imaging camera is arranged so that the crop is clearly and appropriately sized at the center of the screen in order to increase the accuracy of inspection by image processing. In other words, using the standard crop as a reference, set the imaging position so that the center of the crop is located at the center of the screen, and point each imaging camera toward the imaging position so that the surface of the crop is within the depth of field. Deploy. As is apparent from the arrangement of the imaging cameras in FIG. 3 of Patent Document 1, the plurality of imaging cameras are arranged toward the crop at a certain imaging position, and all imaging is performed when the crop reaches a predetermined imaging position. The camera is imaged simultaneously.

  Further, in Patent Document 2, in the moving article imaging apparatus, a moving article detector and an encoder for measuring the moving distance of the moving article are provided, and the moving article being conveyed by the belt conveyor is detected by the moving article detector. Thereafter, it is disclosed that the moving distance of the moving article is measured using an encoder, and the moving article is imaged by operating the imaging device at a timing when the moving distance from the detection position becomes a predetermined distance.

  In Patent Document 3, the number of pixels of a measurement part in an image obtained by imaging a plate-like body is measured, and a predetermined dimension (coefficient) per pixel is applied to the number of pixels of the measurement part to obtain a plate shape. A method of calculating body dimensions from captured images by image processing is disclosed. In Patent Document 3, the dimensions of the plate-like body are calculated. However, in the crop appearance inspection apparatuses of Patent Documents 1 and 2, the dimensions of scratches and heights are calculated by the same method.

JP 2004-249249 A JP 7-333174 A Japanese Patent No. 2640400

  As described above, the orientation and position of the imaging camera are determined according to the crop to be inspected. Agricultural crop sorting device can sort several varieties in a day, and depending on the varieties, the size and shape may vary greatly. There was a need to provide more than one. Furthermore, different types of crops may be sorted according to the season and time, and in this case as well, it is necessary to change the arrangement according to the type of crops or to provide a plurality of types.

  When crops with different sizes and shapes are imaged in the same layout without changing the position of the imaging camera, the center of the crop is shifted from the center of the screen, and the crop image becomes smaller or the image protrudes from the screen. There is. When the image becomes smaller, there are cases where sufficient inspection cannot be performed due to insufficient resolution. Further, if the image protrudes from the screen, the protruding portion cannot be inspected, resulting in an incomplete inspection apparatus. Furthermore, due to the difference in the size and shape of the crop, the distance from the imaging camera to the crop surface changes, so that part or all of the crop surface is outside the range of depth of field, and the image is blurred and insufficient. There is a possibility of inspection.

  In addition, when imaging an article with an imaging camera, when imaging while illuminating the article with illumination, the imaging camera and the illumination are usually integrated, so if the distance from the imaging camera to the surface of the crop is increased Since it is far from the illumination, and as a result, the image becomes dark, it is difficult to make a uniform determination in hue determination or the like. Furthermore, when an imaging camera for imaging the upper side of the article is provided, the illumination from the imaging camera provided on the upstream side and the illumination from the imaging camera on the downstream side are evenly irradiated, that is, The upper imaging camera has to be arranged so that the optical axis of the upper imaging camera is perpendicular to the center of the article at a midpoint between the upstream imaging camera and the downstream imaging camera. If the upper imaging camera is not arranged as described above, unevenness in brightness and darkness due to the illumination on the upstream side and the downstream side occurs in the image, so that uniform determination cannot be performed in hue determination or the like.

  FIG. 15 is a diagram for explaining the above problem, and is a schematic plan view showing an arrangement state of the crops 31a and 31b having different sizes from the arrangement of the imaging cameras 23a to 23d at the time of imaging by the conventional inspection apparatus 21. It is. FIGS. 16A to 16D show images of the crops 31a to 31b having different captured sizes. In FIG. 15, two types of different crops, ie, a large crop 31 a and a small crop 31 b are illustrated as the crops 31 a to 31 b (in FIG. 15, crops other than the imaging position and the detection position D are omitted). . The crops 31a to 31b are sequentially conveyed in the direction of the arrow in a state of being aligned in a row by a conveying means 22 such as a belt conveyor. According to the imaging method described in Patent Document 2, the inspection apparatus 21 detects the crops 31a to 31b that are moved by the moving article detector 24, and moves the crops 31a to 31b using an encoder (not shown). The distance is measured, and the plurality of imaging cameras 23a to 23d are operated simultaneously at the imaging position moved by a predetermined distance from the detection position D, and all the side surfaces of the crops 31a to 31b are imaged at a time. Note that the moving article detector 24 in FIG. 15 is means for detecting when the light beam blocked by the crops again passes, that is, the last part of the crops as the detection position D.

  In FIG. 15, the imaging cameras 23a to 23d are arranged with reference to the largest crop among the transported crops. The imaging cameras 23a to 23d are arranged with a certain distance from the imaging position so that the largest crop is within the screen and the surface of the crop is within the depth of field. Further, the four imaging cameras 23a to 23d are arranged so as to be inclined at 45 ° with respect to the conveyance direction in four directions around the crop so that all sides of the crop can be captured. Furthermore, in order to illuminate the article surface brightly when imaging with the imaging cameras 23a to 23d, illuminations 25a to 25d are provided above the imaging cameras 23a to 23d, respectively.

  FIG. 16A is an image of a large crop 31a by an imaging camera 23a arranged upstream in the conveyance direction (backward of the crop), and FIG. 16B is arranged downstream in the conveyance direction (front of the crop). It is the image of the big crop 31a by the imaging camera 23c. As shown in FIGS. 16A and 16B, since the imaging camera is based on a large crop 31a, the large crop 31a is captured at an appropriate size in the center of the screen.

  FIG. 16C is an image of a small crop 31b by the imaging camera 23a arranged upstream in the conveyance direction (rear of the crop), and FIG. 16D is arranged downstream in the conveyance direction (front of the crop). It is an image of the small crop 31b by the imaging camera 23c. As described above, the apparatus of FIG. 15 captures an image at a timing when the moving distance from the detection position D reaches a predetermined distance (imaging position), and detects the rearmost end of the crop. For this reason, in the imaging camera 23a arranged upstream in the conveyance direction (the rear of the crop), the surface of the large crop 31a and the surface of the small crop 31b at the imaging position are substantially the same distance from the lens of the imaging camera. Therefore, in FIG. 16C, although the image is shifted from the center position, the image of the small crop 31b is the same ratio as the actual ratio compared to the large crop 31a, and is clear. . On the other hand, in the imaging camera 23c arranged downstream in the transport direction (in front of the crop), the surface of the small crop 31b is farther than the surface of the large crop 31a at the imaging position. As a result, the image of the small crop 31b in FIG. 16 (D) is shifted from the center position, and the larger crop 31a is captured smaller than the actual ratio. Furthermore, since it is far from the illuminations 25d and 25c of the imaging cameras 23d and 23c, the image becomes dark. For this reason, the exact size and hue of the small crop 31b cannot be inspected, and in some cases, the image may be too small or too dark to sufficiently inspect the surface scratches.

  Conventionally, because such a problem has occurred, in actual operation, whenever the size of the crop to be imaged changes, the operator manually changes the placement and focus of the imaging camera each time, Such a change work was a burden on the operator, and if the change work was neglected, normal inspection could not be performed. Furthermore, the conventional manual change could not cope with a mixture of crops of different sizes.

Therefore, in order to perform an accurate inspection without involving the manual work of the operator even when crops of different sizes are mixed, the applicant shall It has been proposed to independently set the imaging timing of the imaging cameras arranged on the upstream and downstream sides according to the type (Japanese Patent Application No. 2009-2 7 51 6 1).

  However, when a plurality of imaging timings are set independently, the distance (WD: Work Distance) between each imaging camera arranged on the side and the surface of the target crop is upstream and downstream depending on the imaging timing. The apparent size (number of pixels) of the side image changes for each side image of the crop imaged by each imaging camera. That is, since the correspondence relationship between the size of the captured side image and the actual size of the crop varies, the actual size cannot be calculated from the size of the image based on one coefficient.

  Therefore, for example, even if a scratch or the like is found from the captured image, it is difficult to determine the quality of the crop by correcting the apparent length (number of pixels) of the scratch to the actual length.

  The present invention is based on the above-described conventional technology, while making the most of the equipment of the conventional inspection apparatus as much as possible. As a result, the main object is to provide an article inspection apparatus and method that are more versatile and easy to handle at low cost. Another object of the present invention is to provide an article inspection apparatus and method capable of capturing an appropriate image when an article having a different size or shape is imaged by a plurality of imaging means. To do.

Therefore, an article inspection apparatus according to the present invention is an article inspection apparatus for inspecting the appearance of an article in order to solve the above-described problems, and the article being conveyed by the conveyance means and the article being conveyed by the conveyance means. A first imaging means for imaging the image from above, a second imaging means for imaging the article being conveyed by the conveying means from the side, and a control for controlling the first imaging means and the second imaging means. And the control means acquires a top image of the article imaged by the first imaging means and a side image of the article imaged by the second imaging means, and in each of the acquired images a site, the actual reference site site has a correspondence relation of substantially the same length of the article, the apparent length of the reference site in the acquired top image as a first length Measured, the apparent length of the reference site in the acquired side image as a second length measured, measuring the length of the apparent measurement site in the acquired side image as a third length Then, the third length is converted into an apparent length in the upper surface image based on the correspondence relationship between the measured first length and the second length.

In the article inspection apparatus, the control means converts the first length into an actual article length based on a predetermined first coefficient, and converts the second length into the converted actual length. It is preferable that the second coefficient is calculated based on a correspondence relationship with the length, and the third length is converted into an actual length unit based on the calculated second coefficient.

  Further, the article has a substantially circular horizontal section viewed from the imaging direction of the first imaging means, the reference portion is a diameter of the substantially circular horizontal section, and the first length is: It is preferable that the length of the diameter of the horizontal cross section of the article in the acquired top image, and the second length be the length of the width of the article in the acquired side image.

  In the article inspection apparatus, the second imaging unit includes: an imaging unit that images an article conveyed by the conveying unit from an upstream side in a conveying direction; and an imaging unit that images from an downstream side, The conveying unit conveys a plurality of types of articles having different sizes and shapes, and the control unit independently sets an imaging timing of the upstream second imaging unit and an imaging timing of the downstream second imaging unit. A combination of a plurality of different imaging timings can be set according to the size, shape, or type of the article to be conveyed, and the upstream second imaging means and the downstream second imaging means can be set simultaneously. It is preferable to have a first setting for imaging and a second setting for imaging the upstream second imaging means and the downstream second imaging means at different imaging timings.

  In addition, the second setting is configured to first image the upstream second imaging unit when the article to be imaged in the second setting is smaller than the article to be imaged in the first setting, When the article is conveyed by a predetermined distance and then the downstream second imaging means is imaged, and the article to be imaged with the second setting is larger than the article to be imaged with the first setting, Preferably, the downstream second imaging means is imaged first, and the upstream second imaging means is imaged after the article is conveyed by a predetermined distance.

  Further, the article has a shape in which a horizontal section viewed from the imaging direction of the first imaging means has a major axis and a minor axis, and the conveying means has the major axis or minor axis of the article having the second imaging. Preferably, the orientation of the article is regulated so as to be substantially perpendicular to the imaging direction of the means, and the reference portion is a major axis or a minor axis of the article.

In addition, the article is conveyed by the conveying means, the article is imaged from the upper side by the first imaging means, and the article is imaged from the side by the second imaging means, and a top image and a side image of the article are obtained. An article inspection method for inspecting the appearance of an article based on the acquired top image and side image, wherein the actual article length is substantially the same in each of the acquired images. the site with the reference part, the length of the apparent of the reference part is measured in the acquired top image as a first length, the apparent of the reference site in the acquired side image as a second length And the apparent length of the measurement site in the acquired side image is measured as a third length, and based on the correspondence between the measured first length and second length. And said 3 of the length, characterized in that in terms of the length of the apparent in the upper surface image.

Further, in the article inspection method, the first length is converted into an actual article length based on a predetermined first coefficient, and the correspondence relationship between the second length and the converted actual length. It is preferable that the second coefficient is calculated based on the above and the third length is converted into an actual length unit based on the calculated second coefficient.

  Further, the article has a substantially circular horizontal section viewed from the imaging direction of the first imaging means, the reference portion is a diameter of the substantially circular horizontal section, and the first length is It is the length of the diameter of the horizontal cross section of the article in the acquired top image, and the second length is preferably the length of the width of the article in the acquired side image.

  In the article inspection method, the second imaging unit includes an imaging unit that captures an image of the article being transported by the transport unit from an upstream side in the transport direction, and an imaging unit that captures an image from the downstream side. Depending on the size or type of the article to be processed, the imaging timing of the upstream second imaging means and the imaging timing of the downstream second imaging means are set independently, and the upstream second imaging means Preferably, the downstream second imaging means is imaged at different imaging timings to obtain a plurality of side images of the article.

  According to the present invention, a reference portion of an article to be inspected (corresponding to the fact that the actual article length is substantially the same in the top image taken by the first imaging means and the side image taken by the second imaging means) The portion having the relationship) is viewed from above or viewed from any side by using substantially the same length, that is, the reference portion of the upper surface image captured by the first imaging means. By using the correspondence between the length and the length of the reference portion on the side screen, the length of the portion such as a scratch in the side image is corrected, whereby an accurate inspection can be performed. In addition, since the present invention can be realized at least by adding a control means for correcting the image of the second imaging means, most of the facilities of the conventional inspection apparatus can be used as they are, and more versatile. It is possible to provide an article inspection apparatus that has high performance and is easy to handle at low cost.

  In addition, a control unit that can independently control the imaging timing of the upstream second imaging unit and the downstream second imaging unit respectively disposed on the upstream side and the downstream side of the transport unit is provided and transported by the transport unit. Depending on the size or type of the article to be processed, the control means controls the imaging timing of the second imaging means so that the distance between the article and the second imaging means has a predetermined relationship, and the size or position is appropriate. If an image is obtained, an appropriate image can be obtained for articles of different sizes, and the restriction on the arrangement of the second imaging means is relaxed compared to the conventional case, and the setting is more flexible. Is possible.

  In particular, the first setting for simultaneously imaging the upstream second imaging means and the downstream second imaging means, and the upstream second imaging means are imaged first, and the article is transported a predetermined distance before the downstream In the case of having the second setting for imaging the second imaging means, it is possible to process a standard product having a large quantity at a high speed by the first setting, and the second imaging at the upstream by the second setting. After imaging the rear part of the article at a position close to the means, the article is transported and images the front part of the article at a position approaching the downstream second imaging means. Even an article with a small distance and a small size can obtain a clear image with an appropriate size.

  Further, when the third setting is set such that the downstream second imaging means is imaged first and the article is conveyed by a predetermined distance and then the upstream second imaging means is imaged, the third setting causes the downstream After imaging the front part of the article at a position away from the second imaging means, the article is transported and the rear part of the article is imaged at a position away from the upstream second imaging means. Even if the distance to the surface is increased and the outer shape is large, it is possible to obtain a clear image with an appropriate size.

  In addition, if the measurement means for measuring the size of the article is provided and the control means changes the setting of the imaging timing in accordance with the size of the article measured by the measurement means, it is not necessary to switch the setting by the operator. An appropriate-sized image can be obtained even when goods of various varieties are mixed, or even for articles (mainly agricultural products) having a large size variation within the same variety.

Schematic configuration diagram of the entire article inspection apparatus according to the present invention (A) And (B) is a schematic block diagram which shows other embodiment of arrangement | positioning of several imaging means, respectively. (A)-(C) is a figure which shows the relationship between the arrangement | positioning of an article | item at the time of imaging of each position, and an imaging means, respectively. (A)-(C) is explanatory drawing which shows the upper surface image of the articles | goods (large) (medium) (small) imaged by the 1st imaging means. (A)-(C) is explanatory drawing which shows the side image of the articles | goods (large) (medium) (small) imaged from the upstream by the 2nd imaging means. (A)-(C) is explanatory drawing which shows the side image of the articles | goods (large) (medium) (small) imaged from the downstream by the 2nd imaging means. Flow chart showing a first example of correction processing Explanatory drawing which shows the relationship between the actual length of the reference | standard part of articles | goods, and the 1st length of the reference | standard part in the upper surface image imaged by the 1st imaging means. Flow chart showing a second example of correction processing The figure which shows the relationship between arrangement | positioning of the articles | goods which are spindles, and an imaging means (A) is explanatory drawing which shows the upper surface image of the articles | goods imaged by the 1st imaging means, (B) is the side image of the major axis direction of the articles | goods imaged by the 2nd imaging means of the optical axis orthogonal to a major axis. Explanatory drawing which shows, (C) is explanatory drawing which shows the side image of the short axis direction of the articles | goods imaged with the 2nd imaging means of the optical axis orthogonal to a short axis Explanatory drawing which shows the relationship between the other arrangement | positioning of the articles | goods which are spindles, and an imaging means (A) is explanatory drawing which shows the upper surface image of the articles | goods imaged by the 1st imaging means, (B) is explanatory drawing which shows the side image of the articles | goods imaged by the downstream 2nd imaging means in the arrangement | positioning shown in FIG. Figure The schematic block diagram of the other article inspection apparatus concerning this invention Schematic configuration diagram of conventional inspection equipment (A)-(D) is an example of the image of the crops imaged with the conventional inspection apparatus

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following examples.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of an entire article inspection apparatus 1 according to the present invention. In FIG. 1, an article inspection apparatus 1 includes a conveying means 2 and a plurality of imaging means 3 (3a, 3b, etc. in the drawing are collectively referred to as “3”. 11a, 11b, etc.), an article detection means 4, a conveyance distance measurement means 5, and a control means 6.

  The conveying means 2 uses the driving force from a driving source (not shown) to move the article 11 at the required conveying speed in the direction of the arrow (hereinafter referred to as “conveying direction”, the article supply source side is referred to as the “upstream side”, and the conveying destination side. Is referred to as “downstream side”, and the same applies hereinafter), for example, a belt conveyor, a roller conveyor, an overhead conveyor, a packet conveyor, or the like can be used. The transport means 2 may be able to change the transport speed, and the transport path may be a straight line or a curved line. Furthermore, it is preferable to provide alignment means for aligning articles in a row. As the aligning means, for example, a guide plate for guiding the article to a predetermined position is provided, or the cross-sectional shape of the conveyance path perpendicular to the conveyance direction is V-shaped, and the article is aligned to the predetermined position by inclination. May be. Further, the conveying means 2 may convey the article 11 directly on a belt or a roller, or may convey the article 11 on a container, a plate or the like. However, if the lower surface of the article is also inspected, use transparent containers and dishes.

  The article to be conveyed and inspected is an article that requires images of side surfaces from at least a plurality of angles, and can be applied to an article to be inspected in which an image is captured while being conveyed. Each article has a part (including a region) having a correspondence relationship in which the actual article length is substantially the same between the top image taken from above and the side image taken from the side. This part is hereinafter referred to as “reference part”.

  In the first embodiment, the article to be inspected has a shape in which the horizontal section viewed from above is substantially circular, and the diameter of the horizontal section viewed from above and the width of the body section viewed from the side. Since they have a correspondence relationship that is substantially the same, a substantially circular cross section serves as a reference portion. Examples of such shapes include a sphere, a cylinder, a horizontally long ellipsoid (a flat ellipsoid having a short axis as a rotation axis), a cone, a truncated cone, a torus, and other rotating bodies. As will be described later, even an article having a non-circular cross section may have a reference portion if the orientation of the article and the imaging direction from the side surface satisfy a specific relationship.

  Specific examples of the article 11 include agricultural products such as mandarin oranges, persimmons, pears, pears, peaches, apples, melons, watermelons, tomatoes, strawberries, and avocados, competition balls, various foods in cups and bottles, and the like. Can be mentioned. Note that the article 11 may be a vertically long ellipsoid (a long ellipsoid having a long axis as a rotation axis) when it can be stably conveyed in a vertically placed state using a container or the like. Specific examples of the ellipsoidal object 11 include kiwifruit, strawberries, eggs, and the like. In particular, in the inspection apparatus of the present invention, different types (sizes or shapes) of articles 11 can be transported and inspected. The articles 11 do not need to be transported at regular intervals by the transport means 2 (which may of course be at regular intervals), and are transported in a line at a distance that does not overlap when imaged. It only has to be. In FIG. 1, three types of articles (large) 11a, (medium) 11b, and (small) 11c of large, medium, and small sizes are conveyed.

  The plurality of imaging units 3 are for imaging the appearance of the article 11, and a plurality of imaging units 3 are provided according to the angle at which the article 11 is inspected, and the imaging timing is controlled by the control unit 6. The inspection apparatus 1 according to the present invention includes first imaging means 3d that images the upper surface of the article 11, and second imaging means that images the side surface of the article 11. The second imaging unit is arranged at a different position in the transport direction, and the upstream second image capturing unit 3a that images the article 11 from the upstream side in the transport direction, and the second downstream side that images the article 11 from the downstream side in the transport direction. It is preferable to have the imaging means 3b. The upstream second imaging means 3a and the downstream second imaging means 3b are arranged so as to be able to simultaneously capture and acquire images at a predetermined imaging position with respect to a standard product. In addition, when each imaging unit is provided with illumination, if imaging is performed completely at the same time, the illumination of the opposing imaging unit is incident as backlight and a normal image cannot be obtained. In the meantime, the illumination of the other imaging means was turned off to take an image. For this reason, in the field of inspection apparatuses, simultaneous imaging includes sequential imaging with a time difference of about the shutter speed of the imaging means. For example, assuming that the shutter speed of the imaging means is 1/2000 seconds (= 0.5 ms), when an article is imaged from four directions by four imaging means, the image is taken in a time of about 1/2000 seconds × 4 = 2 ms. Was. This means that when the conveyance speed is 1000 mm / s, the imaging is finished while the article moves 2 mm. That is, the predetermined imaging position does not indicate only one exact point, but also includes an area of about several millimeters, as in the same time. The shutter speed is related to the transport speed. If the transport speed is high, the shutter speed must be shortened so that the image does not blur. Conversely, to increase the shutter speed, the transport speed must be slow. There is a need to. From this, the period included at the same time may be a period in which imaging can be performed at a predetermined imaging position of about several mm.

  Furthermore, an imaging unit (not shown) for imaging the lower surface of the article 11 or a second imaging unit 3c (see FIG. 2B) for imaging the article 11 from the side may be provided. The control means 6 inspects the appearance of the images picked up by the plurality of image pickup means 3. An imaging camera (digital camera) is usually used as the imaging means, but is not limited to such a configuration, and a two-dimensional image may be obtained. Further, the imaging means is not limited to visible light, and may be other imaging means that detects infrared rays, ultraviolet rays, or the like. Furthermore, it is preferable that the imaging means is provided with illumination (not shown) for illuminating the article. As the illumination, an LED lamp or a halogen lamp can be used.

  The upstream second imaging means 3a is for capturing an image of the article 11 from the upstream side in the transport direction and obtaining an image including at least a part of the rear of the article 11 in the transport direction. For this reason, the optical axis of the upstream second image pickup means 3a is set to 0 ° on the downstream side in the transport direction (hereinafter, unless otherwise specified, such a reference is applied to the angle of the optical axis, and the clockwise angle is set to be normal). The angle is less than ± 90 °. Further, the upstream second imaging means 3a may be arranged above the article 11 on the conveying means and may take an image centering on the rear upper part in the conveying direction of the article 11, or arranged below the article 11. And you may image centering on the back lower part of the conveyance direction of the articles | goods 11. FIG. One or more upstream second imaging means 3a can be provided. When there are two upstream second imaging means 3a, the upstream second imaging means 3a are usually arranged symmetrically with respect to the transport means, and the left and right sides on the rear side in the transport direction are arranged. It can be observed at the same time. Conventionally, the optical axes of the two upstream second imaging means 3a are arranged to be ± 45 °. However, in the present invention, since the imaging timing can be controlled independently, the present invention is not limited to such an arrangement. For example, a plurality of upstream second imaging means 3a may be arranged at different positions in the transport direction, or a plurality of upstream second imaging means 3a may be provided at different heights. When there is one upstream second imaging unit 3a, the upstream second imaging unit 3a is arranged at a position that compensates the blind spot of the other imaging unit. In this case, the direction of the optical axis of the upstream second imaging means 3a is preferably in the range of less than ± 30 °.

  The downstream second imaging means 3b is for capturing an image of the article 11 from the downstream side in the transport direction and obtaining an image including at least a part of the front of the article 11 in the transport direction. For this reason, the angle of the optical axis of the downstream second imaging means 3b is in the range of 90 ° to 180 ° or −90 ° to −180 °. Further, the downstream second imaging means 3b may be arranged above the article 11 in the horizontal plane and may take an image centering on the front upper part in the conveyance direction of the article 11, or arranged below the article 11. Thus, the imaging may be performed with the front lower portion in the conveyance direction of the article 11 as the center. One or a plurality of downstream second imaging means 3b can be provided. When there are two downstream second imaging means 3b, they are usually arranged symmetrically with respect to the conveying means, and the right and left sides in front of the conveying direction are arranged. It is arranged so that it can be observed simultaneously. Conventionally, the optical axes of the downstream second imaging means 3b are arranged to be ± 135 °. However, in the present invention, since the imaging timing can be controlled independently, the present invention is not limited to such a symmetrical arrangement, and a plurality of downstream second imaging means 3b may be arranged at different positions in the transport direction. Alternatively, a plurality of downstream second imaging means 3b may be provided at different heights. In addition, when there is one downstream second imaging unit 3b, the downstream second imaging unit 3b is arranged at a position that compensates the blind spot of the other imaging unit. In this case, it is preferable that the angle of the optical axis of the downstream second imaging means 3b is in the range of 150 ° to 180 ° or −150 ° to −180 °.

  In FIG. 1, as a plurality of image pickup means, there are a first image pickup means 3d for observing the upper surface, two upstream second image pickup means 3a, and two downstream second image pickup means 3b. And an imaging unit (not shown) for observation. The two upstream second imaging means 3a are arranged symmetrically with respect to the conveying means, and their optical axes are arranged so as to be 45 ° and −45 °, respectively, with respect to the conveying direction. The second imaging means 3b is also arranged symmetrically with respect to the conveying means, and their optical axes are arranged so as to be 135 ° and −135 °, respectively, with respect to the conveying direction. It is preferable that the optical axes of the two upstream second imaging means 3a and the optical axes of the two downstream second imaging means 3b are arranged so as to intersect at one point. Further, a first imaging unit 3d for observing the upper surface is disposed above the center of the article 11, and an imaging unit (not shown) for observing the lower surface is disposed below the center of the article 11. Typically, in order to match the imaging timing, imaging for observing the first imaging unit 3d and the lower surface above and below the intersection of the optical axes of the upstream second imaging unit 3a and the downstream second imaging unit 3b. Means (not shown) are arranged.

  2A and 2B show another embodiment of the arrangement of a plurality of imaging units, respectively. FIG. 2A shows two upstream second imaging units 3a and one downstream second imaging unit. FIG. 4B is an example of an embodiment including an imaging unit 3b, and FIG. 5B illustrates one upstream second imaging unit 3a, one downstream second imaging unit 3b, and an optical axis perpendicular to the transport direction. It is an example of embodiment provided with the 2nd imaging means 3c of one side which has. In FIG. 2A, two upstream second imaging means 3a whose optical axis directions are 60 ° and −60 ° are arranged symmetrically with respect to the transport direction, and on the downstream side, the optical axis direction is One downstream second imaging means 3b of 180 ° is arranged on the transport path. The intersections of the optical axes of the imaging units are arranged so as to intersect on the transport unit. The crossing here is an arrangement for imaging the entire periphery of the article 11 by simultaneously imaging each imaging unit, and is not only when the optical axes of each imaging unit strictly intersect at one point. In addition, the case where there is some deviation in the vertical and horizontal directions within the range of the article 11 is also included. In FIG. 2B, one upstream second imaging means 3a with an optical axis direction of 30 °, one downstream second imaging means 3b with an optical axis direction of 150 °, and the optical axis direction. The second imaging means 3c on one side surface of −90 ° is arranged. In FIG. 2B as well, the intersections of the optical axes of the imaging units are arranged so as to overlap the center of the article 11. The imaging timing of the second imaging means 3c on the side surface of FIG. 2B is preferably taken when the center of the article reaches the optical axis, regardless of the size of the article.

  In FIG. 1, the article detection unit 4 and the transport distance measurement unit 5 are part of the position specifying unit. The article detection unit 4 detects the article 11, and then the transport distance measurement unit 5 detects the position. By measuring the distance from the control means 6, the control means 6 can specify the current position of the article 11 to be conveyed. However, the position specifying means is not limited to such a configuration. For example, if the conveyance speed is constant, the position can be specified by combining the article detection means 4 and a clock circuit (such as a crystal resonator) that measures time. When imaging is started at the detection position of the article detection means 4, the position of the article 11 can be specified by providing a plurality of article detection means 4 and the arrangement of the detected article detection means 4. Further, it may be a completely different means, for example, a position specifying means for specifying a position of the article 11 placed on the container by attaching a radio wave oscillator to a container on which the article 11 is placed and receiving the radio wave. That is, in order to control the timing of imaging, if the position of the article 11 to be conveyed can be specified, it can be used as a position specifying means.

  Further, the article detection means 4 and the conveyance distance measurement means 5 measure the distance from when the article detection means 4 detects the article 11 until it is no longer detected, so that the control means 6 Since the length of 11 can be measured, it can function as a measuring means. However, like the position specifying means described above, the measuring means is not limited to such a configuration, and other means can be used as the measuring means as long as the size of the article 11 can be measured.

  The article detection unit 4 includes a sensor that detects at least a point imaged by the imaging unit 3 on the conveyance path of the conveyance unit 2 or the presence of the article 11 arranged upstream from the point. As the article detection means 4, for example, a combination of a light emitting element and a light receiving element can be used, and the front end portion of the article can be detected by blocking the light from the light emitting element. When the light receiving element starts to receive light, the rear end of the article can be detected. However, the article detection means 4 is not limited to such a configuration, and a pressure sensor, an infrared sensor, or the like can be used as appropriate. Information on the article 11 detected by the article detection unit 4 is input to the control unit 6.

  The conveyance distance measuring means 5 measures the conveyance distance of the article 11 by the conveyance means 2 and controls the imaging timing by measuring the distance from the position detected by the article detection means 4. is there. As the transport distance measuring means 5, for example, a pulse generator such as an encoder may be connected to a rotating shaft (not shown) of the conveyor to detect the rotation angle of the rotating shaft, and the transport distance may be measured. The conveyance distance may be measured by detecting time. Information relating to the distance detected by the transport distance measuring means 5 is input to the control means 6.

  The control means 6 controls at least the imaging timings of the plurality of imaging means 3, and in the present invention, among the plurality of imaging means 3, the imaging timing of the upstream second imaging means 3a and the downstream second imaging. The imaging timing of the means can be set independently. The control means 6 can set a plurality of combinations of the imaging timing of the upstream second imaging means 3a and the imaging timing of the downstream second imaging means 3b in accordance with the size or type of the article 11. For this reason, even if the size and type of the article 11 to be conveyed change, it is possible to use the article inspection apparatus 1 only by changing the setting of the imaging timing. In addition, the control unit 6 acquires a top image captured by the first imaging unit 3d and a side image captured by the second imaging unit 3a, 3b, and inspects the appearance of the article by image processing.

  Furthermore, the control means 6 may also control other functions of the article inspection apparatus 1. For example, activation and termination of the apparatus, adjustment of the conveyance speed, and control of setting of the conveyance path may be performed, or a captured image may be processed. As the control means 6, for example, an information processing apparatus having an arithmetic function and a storage function can be used. The arithmetic function may be configured by a processor, for example. The storage function may be configured by, for example, a semiconductor memory, a hard disk device, or the like. For example, the processor implements various processes by executing a program loaded from the hard disk device to the semiconductor memory.

  The combinations of imaging timings can be roughly classified into the following three patterns. However, as will be described later, in the case of the second pattern and the third pattern, a plurality of combinations of different imaging timings can be set in one pattern.

First pattern: a pattern in which the upstream and downstream second imaging means 3a and 3b are imaged simultaneously Second pattern: a pattern in which the upstream second imaging means 3a is first imaged and then the downstream second imaging means 3b is imaged Third pattern: pattern in which the downstream second imaging unit 3b is imaged first, and then the upstream second imaging unit 3a is imaged

  The first pattern is substantially the same as the imaging timing in the prior art, but the imaging timing of the upstream and downstream second imaging means 3a and 3b can be set independently. Is possible. Since the first pattern can be processed at high speed, it is preferable that the inspection apparatus 1 has an imaging timing of an article 11 (hereinafter referred to as “standard product”) that is a standard or most frequent item. The imaging position (position A) of the first pattern is one point, and the upstream and downstream second imaging means 3a and 3b are such that the article 11 is clear and appropriate in size at the center of the screen at the imaging position A. It is preferable that the images are arranged so as to be an image. In FIG. 1, the article (medium) 11b is a standard product. In FIG. 1, the position A is set so that the center of the article 11 (medium) is arranged at the intersection of the optical axes of the respective imaging means 3.

  In the second pattern, the upstream second imaging unit 3a captures an image at the upstream position B1 of the transport path, and then the downstream second imaging unit 3b captures an image at the downstream position B2. The second pattern is preferably applied to an article that is smaller than a standard product. That is, after imaging the rear part of the article 11 at the position B1 close to the upstream second imaging means 3a, the article 11 is conveyed, and the front part of the article 11 is imaged at the position B2 approaching the downstream second imaging means 3b. To do. For this reason, even if the distance from each imaging means to the surface of the article 11 is small and the size is small, it is possible to obtain a clear image with an appropriate size. In the second pattern, the distance between the upstream second imaging means 3a and the position B1 and the distance from the downstream second imaging means 3b to the position B2 are substantially the same, so that the size of each captured image (actual thing) And the ratio thereof are preferable.

  The second pattern merely specifies the order, and the imaging timing (position B1) of the upstream second imaging means and the imaging timing (position of the downstream second imaging means) depending on the size and type of the article 11. Each of B2) can be changed. For this reason, even if the combination of the imaging timings set in the control means 6 is only the second pattern, a plurality of combinations of different imaging timings can be set by changing the setting of the position B1 or the position B2.

  The third pattern is to pick up an image by the downstream second image pickup means 3b at the upstream position C1 of the transport path, and then cause the upstream second image pickup means 3a to pick up an image at the downstream position C2. The third pattern is preferably applied to an article that is larger than a standard product. That is, after imaging the front part of the article 11 at a position C1 away from the downstream second imaging means 3b, the article 11 is transported, and the rear part of the article 11 at the position C2 away from the upstream second imaging means 3a. Take an image. For this reason, even if the distance from each imaging means to the surface of the article 11 is increased and the outer shape is large, it is possible to obtain a clear image with an appropriate size. In the third pattern, the distance between the upstream second imaging means 3a and the position C2 and the distance from the downstream second imaging means 3b to the position C1 are substantially the same, so that the size of each captured image (actual thing) And the ratio thereof are preferable.

  The third pattern merely specifies the order, and the imaging timing (position C1) of the upstream second imaging means and the imaging timing (position of the downstream second imaging means) according to the size and type of the article 11. C2) can be changed respectively. For this reason, even if the combination of the imaging timings set in the control means 6 is only the third pattern, a plurality of combinations of different imaging timings can be set by changing the setting of the position B1 or the position B2.

  Note that the above three patterns are classified only for the imaging timing of the upstream and downstream second imaging means 3a and 3b, and when there are provided imaging means for imaging the upper surface, right side, and lower surface, The pattern further increases depending on the imaging timing. However, basically, the image pickup means for picking up the upper surface, the right side, and the lower surface is picked up at the timing when the center of the article is positioned on the optical axis of the image pickup means.

  Furthermore, it is preferable that the control means 6 can measure the length of the article 11 by the article detection means 4 and the transport distance measurement means 5 and can automatically change the setting of the imaging timing based on the length. In this case, as the setting of the imaging timing, the first setting is registered in the control unit 6 for the length of a certain range, and the second setting is registered for the other range, and the measured length belongs to any range. It may be determined whether the setting is changed. In this case, an appropriate image can be obtained according to the length of the article regardless of the type of the article. Further, the type of the article may be determined from the measured length, and the setting may be changed to the setting for the determined type of article. In this case, it is possible to carry out an inspection (for example, sorting process, color, etc.) specific to the identified type of article. Further, the imaging timing may be changed by calculating the imaging position by inputting the measured length of the article to the function for obtaining the imaging position. In this case, a more appropriate image can be obtained according to the length of the article regardless of the type of the article.

  The image pickup positions A, B1, B2, C1, and C2 can be set by the detection position D of the article detection means 4 and the distance (including 0) therefrom. As the imaging timing, which part of the article reaches the imaging position is not so important. If the relative positional relationship between the article and the imaging means at the time of imaging is the same, the part and position of the article The relationship can be set as appropriate. That is, the timing at which the tip of the article having a length of 10 cm reaches position A is the same as the timing at which the center of the article reaches a position 5 cm upstream of position A, and further, The timing is the same as when the end reaches the position 10 cm upstream of the position A. Therefore, it is only necessary to set a part and an imaging position that are reached from a part or the like where the article is detected by the article detection unit 4. When the center of the article is obtained by the measuring means, the length of the article is measured and a half of the article is calculated. In FIG. 1, each imaging position is set at a position reached by the rear end of the article 11.

  In FIG. 1, position A, position B1, and position C2 are the same position, position B2 is set downstream of these positions A, B1, and C2, and position C1 is set upstream.

  FIG. 3A is a diagram showing the relationship between the arrangement of the articles 11a and 11c and the imaging means at the time of imaging the positions B1 and C2, and FIG. 3B shows the arrangement of the article 11c and the imaging means at the time of imaging the position B2. The figure (C) is a figure which shows the relationship between arrangement | positioning of the articles | goods 11a regarding the position C1, and an imaging means. In FIGS. 3A to 3C, as a reference, an article 11b which is a standard object at the position A is indicated by a dotted line, and unused imaging means are shaded.

  In FIG. 3A, the upstream second imaging means 3a operates at the timing when the article (small) 11c reaches the position B1, but the downstream second imaging means 3b does not operate. For this reason, only the rear part of the article (small) 11c at the position B1 is imaged. Even at the timing when the article (large) 11a reaches the position C2, the upstream second imaging means 3a operates to image only the rear part of the article (large) 11a at the position C2.

  For the first image pickup means 3d and other image pickup means (straight side, bottom face image pickup means) arranged in the direction perpendicular to the transport direction, the timing when the center of each article is positioned on the optical axis of each image pickup means. However, the imaging timing of the first imaging means 3d and other imaging means (straight side, bottom surface imaging means) is not limited to this, so that the entire article is captured in the images on each surface. Any imaging timing may be used. For example, the first imaging unit 3d and other imaging units (straight side, bottom surface imaging unit) may capture images in accordance with the imaging timing of the second imaging unit 3a or 3b (also in FIGS. 3B and 3C). the same). 1 and 3, when the position A, the position B1, and the position C2 are matched, the distance from the upstream second imaging means 3a to the rear surface of the articles 11a and 11c is almost the same as that of the standard article (medium) 11b. Since it becomes the same, the image about the rear part of the articles | goods 11a and 11c can obtain a clear image like a standard product, and is preferable. However, the position A, the position B1, and the position C2 are not necessarily matched. In consideration of the size of the article, the position B1 and the position C2 can be adjusted within the range of the depth of field so that the image of the article fits within the screen.

  In FIG. 3 (B), the downstream second imaging means 3b operates at the timing when the article (small) 11c reaches the position B2 arranged on the downstream side of the position B1. For this reason, only the front part of the article (small) 11c at the position B2 is imaged. In FIG. 3B, the front end of the article (small) 11c at the position B1 is aligned with the front end of the article (medium) 11b which is a standard product. For this reason, since the distance from the downstream second imaging means 3b to the front surface of the article 11c is substantially the same as that of the article 11b which is a standard product, the image of the front part of the article 11c is clear as in the standard product. It is preferable that a clear image can be obtained. However, it is not always necessary to align the front end with the standard product. In consideration of the size of the article, the position B2 can be adjusted within the range of the depth of field so that the image of the article fits within the screen.

  In FIG. 3C, the downstream second imaging means 3b operates at the timing when the article (large) 11a arrives at the position C1 arranged on the upstream side of the position C2. For this reason, only the front part of the article (large) 11a at the position C1 is imaged. In FIG. 3C, the front end of the article (large) 11a at the position C1 is aligned with the front end of the article (medium) 11b which is a standard product. For this reason, since the distance from the downstream second imaging means 3b to the front surface of the article 11a is substantially the same as that of the article 11b which is a standard article, the image of the front part of the article 11a is as clear as the standard article. It is preferable that a clear image can be obtained. However, it is not always necessary to align the front end with the standard product. Considering the size of the article, the position C1 can be adjusted within the range of the depth of field so that the image of the article fits within the screen. For convenience of explanation, the position C2 in FIG. 3A has been described earlier, but actually, the imaging of the position C1 arranged on the more upstream side is performed before the imaging of the position C2.

  In the present embodiment, the control unit controls the distance between the articles 11a to 11c and the second imaging units 3a and 3b according to the size or type of the articles 11a to 11c conveyed by the conveyance unit. A plurality of different imaging timings are set. For this reason, even if it is articles | goods 11a-11c from which a magnitude | size differs, the side image of a suitable magnitude | size can each be obtained. However, since the distance (WD) between the second imaging means 3a and 3b and the articles 11a to 11c varies depending on the set imaging timing, the apparent size of the captured side image (the number of pixels constituting the side image) Is different for each article 11 and for each second imaging means 3a, 3b. That is, the correspondence between the size of the captured side image and the actual size of the crop varies. Furthermore, the correspondence between the size of the side image and the actual size of the crop varies with the correspondence between the size of the top image and the actual size of the crop.

  4 (A) to 4 (C) are explanatory views showing the top image 12 of the article (large) 11a, (medium) 11b, (small) 11c--captured by the first imaging means, and FIG. A) to (C) and FIGS. 6A to 6C are side views of articles (large) 11a, (medium) 11b, and (small) 11c imaged from the upstream and downstream second imaging means, respectively ( It is explanatory drawing which shows the back surface image 13 and the side (front) image 14. FIG. 4 to 6, the article (large) 11a is a cylinder, the article (medium) 11b is a flat ellipsoid, and the article (small) 11c is a truncated cone.

  The top image 12a of the article 11a shown in FIG. 4A is an image taken at the imaging timing when the center of the article 11a reaches the optical axis of the first imaging unit 3d, for example. The side image 13a of the article 11a shown in FIG. 5 (A) is the second upstream image when the rear end of the article 11a reaches the position C2 (see FIG. 3 (A)) according to the imaging timing of the third pattern. It is the image of the rear surface of the article | item 11a imaged by the means 3a. The side image 14a of the article 11a shown in FIG. 6 (A) is a second downstream image when the rear end of the article 11a reaches the position C1 (see FIG. 3 (C)) according to the imaging timing of the third pattern. It is the image of the front surface of the articles | goods 11a imaged by the means 3b.

  The top image 12b of the article 11b shown in FIG. 4B is an image taken at the imaging timing when the center of the article 11b reaches the optical axis of the first imaging unit 3d, for example. The side image 13b of the article 11b shown in FIG. 5B is a second upstream image when the rear end of the article 11b reaches the position A (see FIG. 3A) according to the imaging timing of the first pattern. It is the image of the rear surface of the article | item 11b imaged by the means 3a. The side image 14b of the article 11b shown in FIG. 6B is the second downstream image when the rear end of the article 11b reaches the position A (see FIG. 3B) at the first pattern imaging timing. It is the image of the front surface of the article | item 11b imaged by the means 3b.

  The top image 12c of the article 11c shown in FIG. 4C is an image taken at the imaging timing when the center of the article 11c reaches the optical axis of the first imaging unit 3d, for example. The side image 13c of the article 11c shown in FIG. 5C is the second upstream imaging when the rear end of the article 11c reaches the position B1 (see FIG. 3A) at the imaging timing of the second pattern. It is the image of the back surface of the article | item 11c imaged by the means 3a. The side image 14c of the article 11c shown in FIG. 6C is the second downstream imaging when the rear end of the article 11c reaches the position B2 (see FIG. 3B) at the second pattern imaging timing. It is the image of the front surface of the article | item 11c imaged by the means 3b.

  The imaging timing of the top image 12 is not limited to the imaging timing when the center reaches the optical axis of the first imaging unit 3d. Further, the apparent size of the article 11 in the rear side image 13 and the front side image 14 does not need to match.

  The reference part in each upper surface image 12 has a substantially circular diameter formed by a horizontal cross section. Hereinafter, the length of the reference portion in the top image 12 is referred to as “first length”. In FIG. 4A, the first length of the reference portion (substantially circular diameter) is indicated by “L1”. The first length (L1) may be indicated in units of pixels (pixels), for example. Hereinafter, the length of the reference portion in the actual article is referred to as “L”.

  The reference portion in the rear side image 13 and the front side image 14 is the maximum width of the object body. Hereinafter, the length of the reference portion in the side images 13 and 14 is referred to as “second length”. In FIG. 5A, the second length is indicated by “L2”. The second length (L2) may be indicated in units of pixels, for example. The reference portion in the top image and the side image has a corresponding relationship in the actual article, and the length of the reference portion is substantially the same “L” because the horizontal cross section is substantially circular.

  The top image 12 and the side images 13 and 14 are parts that need to be measured in size or length in inspection, such as parts or heights with scratches, discoloration, dirt, etc. on the surface of the article 11 (hereinafter referred to as “measurement”). May be included.) 15 and 16. 4 to 6, the measurement site cannot be confirmed in the top image 12, but the measurement sites 15 and 16 can be confirmed in the side images 13 and 14. Hereinafter, the length of the measurement parts 15 and 16 is referred to as “third length”, and the third length is referred to as “L3”. The third length L3 may be indicated in units of pixels, for example. Hereinafter, the length of the measurement site in the actual article 11 is described as “X”.

  As shown in FIGS. 4 to 6, in the present embodiment, the top image 12 is captured by the first imaging unit 3 d regardless of the size and type of the article 11. The imaging is performed at the imaging timing when the optical axis is reached. For this reason, the size of the top image 12 and the size of the actual article 11 are correlated, and by multiplying the size and area (coefficient) per pixel, the size of the top article 12 and the actual size of the article 11 are obtained. And the area can be calculated.

  The side images 13 and 14 are imaged at a plurality of imaging timings corresponding to the size and type of the article 11 by the upstream and downstream second imaging means 3a and 3b. For this reason, the side images 13 and 14 having appropriate sizes can be obtained for the articles 11 having different sizes and types. However, the lengths of the measurement portions 15 and 16 in the side images 13 and 14 are difficult to compare depending on the appearance because the sizes of the side images 13 and 14 are not correlated with the actual size of the article 11. . Therefore, in the present invention, the length of the measurement site in the side image is corrected based on the correspondence between the reference site in the top image and the reference site in the side image. Hereinafter, the correction process will be described.

  FIG. 7 is a flowchart illustrating a first example of the correction process. First, the control unit 6 acquires a top image captured by the first imaging unit 3d and a plurality of front and rear side images captured by the second imaging unit 3a and 3b for a certain article 11 (S701). Next, the control means 6 selects a reference region (horizontal cross-sectional diameter) in the acquired upper surface image, and measures the first length (L1) in units of pixels (S702). Next, the control means 6 selects a reference part (maximum width of the trunk) in each acquired side image, and measures the second length (L2) in units of pixels (S703). Next, the control means 6 selects a measurement site (a site with scratches, dirt, discoloration, etc.) in each acquired side image, and measures a third length (L3) in units of pixels (S704). .

And the control means 6 is based on ratio (L1 / L2) of 1st length (L1) and 2nd length (L2), 3rd length (L3) of the measurement site | part in a side image. Is corrected (S705). Specifically, the ratio (L1 / L2) is multiplied by the third length (L3) of the measurement site by the following formula 1.
Third length after correction = (L1 / L2) × L3 (Expression 1)

  Thereby, it is possible to calculate how many pixels the length of the measurement site in the side image corresponds to in the top image. If there is no other side image or measurement site as a target, the control means 6 ends the correction process (S706). Note that the steps are not limited to the order shown in FIG. 7 and may be appropriately changed within a range where calculation is possible. For example, steps S702 to S704 may be processed in any order. Further, step S705 only needs to finally obtain Equation 1 above. For example, the ratio (L3 / L2) between the third length (L3) and the second length (L2) is set to the first value. The length (L1) may be multiplied.

  By this correction processing, the length of the measurement site in the side image captured at different imaging timings can be converted into the number of pixels in the top image, so that the appearance of the article can be accurately inspected. The control means 6 may perform a comparison process between the predetermined threshold and the corrected length of the measurement site after the above-described correction process to determine the quality of the article. When a plurality of threshold values are set, the article inspection apparatus can classify the articles into several classes according to the length of the scratches on the articles.

  By the way, in this embodiment, since the top image is always imaged at a fixed point by the first imaging means 3d, the distance (WD) between the surfaces of the articles 11a to 11c and the first imaging means 3d is substantially constant. . Therefore, since the angle of view, the focal length, and the like of the first imaging unit 3d are substantially constant, the apparent sizes of the top images 12a to 12c of the articles 11a to 11c imaged by the first imaging unit 3d are the articles 11a to 11a. This corresponds to the actual size of 11c. Therefore, in the present embodiment, a coefficient (hereinafter referred to as “first coefficient”) for correcting the length (for example, pixels) in the top image to the actual length (for example, mm) is set in advance or It can be obtained by calculation.

  FIG. 8 is an explanatory diagram showing the relationship between the actual length L of the reference part of the article and the first length L1 of the reference part in the top image captured by the first imaging means. The vertical axis is an axis indicating the actual length L (for example, in mm) of the reference region, and the horizontal axis is the first length L1 (for example, pixel) of the reference region in the captured top image. Is a unit).

The squares shown in FIG. 8 are measured values of the article (large) 11a (for example, grapefruit). A triangle is a measured value of article (medium) 11b (for example, Iyokan). A circle is a measurement value of the article (small) 11c (for example, mandarin orange). The straight line shown in FIG. 8 is a straight line calculated by, for example, the least square method, and is a straight line connecting points that minimize the square of the difference from the measured value indicated by each circle, triangle, and square. The relationship between L and L1 is expressed by the following equation 2 using the slope k of this straight line. That is, the slope k of this straight line can be set as the first coefficient.
L = k × L1 (Expression 2)

  Here, since the horizontal cross section of the article 11 is substantially circular, the actual diameter of the reference portion viewed from above and the actual width of the reference portion in the side image are substantially the same and are “L”. . Therefore, when the correspondence relationship between the first length L1 and the second length L2 and the first coefficient set in advance are used, the second length (for example, pixel) and the third length in the side image are determined. A coefficient for correcting the length to an actual length (for example, mm) (hereinafter, referred to as “second coefficient (j)”) can be calculated.

  Hereinafter, based on a preset first coefficient k, a second coefficient is calculated for each captured side image, and the third length of the measurement site in each side image is converted to an actual length. Will be described.

  FIG. 9 is a flowchart illustrating a second example of the correction process. First, the control unit 6 acquires a top image captured by the first imaging unit 3d and a plurality of front and rear side images captured by the second imaging units 3a and 3b for an article 11 (S901). Next, the control means 6 selects a reference region (horizontal cross-sectional diameter) in the acquired upper surface image, and measures the first length L1 in units of pixels (S902). Next, the control means 6 selects a reference portion (maximum width of the trunk) in each acquired side image, and measures the second length L2 in units of pixels (S903). Next, the control means 6 selects a measurement site (a site with scratches, dirt, discoloration, etc.) in each acquired side image, and measures the third length L3 in units of pixels (S904).

  And the control means 6 acquires the preset 1st coefficient k (S905). In addition, when the height of each article 11 to be conveyed is significantly different, strictly speaking, the distance (WD) between the surface of the article 11 and the first imaging unit 3d is not constant. Therefore, in this case, a plurality of first coefficients may be set in advance according to the height of the article 11. Specifically, for example, when the article 11 passes through the position D, the article detection unit 4 detects the height of the article 11, and the control unit 6 is preset based on the detected height of the article 11. One first coefficient k of the plurality of first coefficients is acquired.

Next, the control means 6 converts the first length L1 in the top image into the actual length L based on the following equation 3 using the acquired first coefficient k (S906).
L = k × L1 (Formula 3)

Next, the control means 6 calculates the second coefficient j by the following equation 4 based on L2 measured in step S903 and L converted in step S906 (S907).
j = k × (L1 / L2) (Formula 4)

Finally, based on the calculated second coefficient j, the control means 6 converts the third length L3 of the measurement site in the side image into the actual length X by the following equation 5 (S908).
X = j × L3 (= k × (L1 / L2) × L3) (Expression 5)

  The control means 6 ends the correction process if there are no other side images and measurement sites as targets (S909). Note that the steps are not limited to the order shown in FIG. 9 and may be appropriately changed within a range where calculation is possible. For example, step S905 may be executed before S901, and steps S902 to S904 may be executed in any order. With the above correction processing, the third length L3 of the measurement site in the side images captured at different imaging timings can be converted into the actual length X, so that the appearance of the article can be accurately inspected. . The control means 6 may perform a comparison process between the predetermined threshold value and the actual length of the measurement site after the above-described correction process, and determine the quality of the article.

  If a measurement site (a site with scratches, dirt, discoloration, etc.) is also observed in the top image, in step S906, the control unit 6 determines the length of the measurement site in the top image based on the first coefficient k. May be converted into an actual length. In step S908, the control unit 6 may convert the height of the side image to the actual height in addition to the measurement site in the side image based on the second coefficient j. In this case, the approximate volume of the article may be calculated based on the actual length L (corresponding to the width of the article) of the converted second length and the actual height.

  Furthermore, when the measurement site is not a line but is, for example, a region having a width, the control unit 6 calculates the area (number of pixels) of the measurement site in the side image in step S904, and is calculated in step S908. Alternatively, the area of the measurement site in the side image may be converted into the actual area based on the second coefficient (the square of the coefficient of the length).

  In addition, the control means 6 displays a top image and a side image of the article 11 on a display device (for example, a liquid crystal display) (not shown) provided in the article inspection apparatus, and further, for example, in units of mm or cm. The inspection results of the length / area of the article 11 such as the width, height, diameter, and scratches may be displayed. The inspector may correct the determination by the article inspection apparatus based on the inspection results displayed on the display device.

  The correction processing of the present invention can also be applied to a conventional article inspection apparatus in which the imaging timing of the second imaging unit is fixed.

  In the conventional article inspection apparatus, since the imaging timing of the second imaging means is fixed, the apparent size of the side image corresponds to the actual size of the article to be imaged. Therefore, in the conventional article inspection apparatus, as in FIG. 15, the relationship between the length (number of pixels) of the reference portion in the side image and the actual length of the reference portion in the article is obtained in advance by experiments or the like. Based on the result, the second coefficient j for converting the length of the measurement site in the side image into the actual length has been set. However, since the second coefficient j is set for each second imaging means, when the arrangement of the imaging means is changed, the second coefficient j is set for all imaging means (first and second imaging means). There was a need to seek and set.

  When the correction process of the present invention is applied to a conventional article inspection apparatus, the length of the measurement site can be calculated and determined based on the correspondence relationship between the first length L1 and the second length L2. Furthermore, since the second coefficient j can be calculated from the first coefficient k, it is not necessary to obtain the second coefficient j by an experiment or the like in advance, and even when the setting is changed, the second coefficient j can be calculated. Only one coefficient k needs to be changed.

[Second Embodiment]
In the second embodiment, the shape of an article to be inspected is limited to a rotating body such as a sphere, an elliptical body, a cylinder, or a truncated cone having a substantially circular horizontal cross section as described in the first embodiment. For example, a horizontally placed spindle, a horizontally placed ellipsoid, a horizontally placed cylinder, or the like may be used. The horizontal cross section viewed from above is an ellipse, a spindle, and a rectangle. Hereinafter, in these horizontal sections, the axis in the length direction of the article is referred to as a major axis (La), and the axis in the width direction of the article is referred to as a minor axis (Lb) (the major axis and the minor axis may be the same). Examples of the article 11d having such a shape include lemon and sweet potato.

  In the case of an article having a major axis and a minor axis, the arrangement of the article 11d when the article 11d is conveyed by the conveying means 2 and the arrangement of the second imaging means must satisfy a predetermined relationship. The predetermined relationship is a relationship in which the optical axis of the second imaging unit and the major axis (La) or the minor axis (Lb) of the article 11d are always at substantially the same angle. Usually, since the optical axis of the second imaging unit is fixed, when the article 11d is conveyed by the conveying unit 2, the direction of the article 11d is regulated so as to satisfy the predetermined relationship. The angle between the optical axis of the second image pickup means and the major axis (La) or the minor axis (Lb) of the article 11d is preferably substantially a right angle, but is not limited to a right angle. 10 and 11 will be described below, but examples other than the right angle will be described in FIGS. 12 and 13 to be described later.

  10, the arrangement of each imaging means is the same as the configuration of the article inspection apparatus shown in FIG. 1, and the two upstream second imaging means 3a are arranged symmetrically with respect to the conveying means, and their light The axes are arranged at 45 ° and −45 ° with respect to the conveyance direction, respectively, and the two downstream second imaging means 3b are also arranged symmetrically with respect to the conveyance means, and their optical axes are in the conveyance direction. In contrast, they are arranged to be 135 ° and −135 °, respectively. Further, in FIG. 10, the article 11d to be inspected has its long axis (La) oriented at −45 ° with respect to the conveyance direction and the short axis (Lb) is in the conveyance direction by the regulating means (not shown). Is conveyed by the conveying means 2 in a state of being arranged at an angle of 45 ° to the angle. For example, a bucket or a belt conveyor formed with a V-shaped groove can be used as the regulating means.

  In FIG. 10, the spindle article (eg, lemon, sweet potato, etc.) is illustrated as the article 11d to be inspected. However, the article is not limited to this, and for example, an article having a substantially circular horizontal cross section similar to the embodiment. In addition, it is possible to inspect articles having a substantially elliptical horizontal cross section (for example, potato, eggplant, avocado, etc.) and objects having a substantially rectangular horizontal cross section (for example, long, radish, long onion, cucumber, etc.).

  Furthermore, each imaging means is not limited to the arrangement shown in FIG. 10, and may be an arrangement as shown in FIG. 2A or 2B, for example. Moreover, you may arrange | position the 2nd 2nd image pick-up means 3c of the right side which images one side and the other side of 11 d of articles | goods. As shown in FIG. 2B, in the case where the second image pickup means 3c just beside is arranged, or in the case where the two second image pickup means 3c right beside are arranged, the restricting means is the long axis of the article 11d. However, the article 11d may be placed so that the major axis and the optical axis are orthogonal to each other at 0 ° with respect to the transport direction. In this case, the restricting means may be constituted by, for example, two belt conveyors inclined in a V shape, and the direction of the article 11d may be restricted such that the major axis direction is the conveying direction.

  The upstream second imaging unit 3a and the downstream second imaging unit 3b preferably capture images simultaneously when the center of the article 11d reaches each optical axis. That is, in the second embodiment, the first pattern in the first embodiment is used as a combination of imaging timings.

  Further, a first imaging unit 3d for observing the upper surface is disposed above the center of the article 11. The first imaging means 3d is arranged so that its optical axis is a vertical axis passing through the intersection of the optical axes of the second imaging means 3a and 3b. The first imaging unit 3d captures a top image of the article 11d when the center of the article 11d reaches the optical axis.

  When setting the imaging timing, for example, an article detection unit (not shown) may detect the front end and the rear end of the conveyed article 11d. Then, the transport distance measuring means 5 measures the transport distance of the article 11d. Thereby, the control means 6 can calculate the position of the center of the article 11 being conveyed, and can calculate the timing at which the center position reaches the intersection of the optical axes.

  FIG. 11A is an explanatory view showing a top image of the article 11d imaged by the first imaging means 3d. FIG. 11B is an explanatory view showing a side image in the major axis direction of the article 11d imaged from the upstream or the downstream by the second imaging means 3a or 3b having an optical axis perpendicular to the major axis of the article 11d. FIG. 11C is an explanatory view showing a side image in the short axis direction of the article 11d imaged from the upstream or the downstream by the second imaging means 3a or 3b having an optical axis perpendicular to the short axis of the article 11d.

  The top image 12d is an image captured at the imaging timing when the center of the article 11d reaches the optical axis of the first imaging unit 3d. The side image 13d and the side image 14d are images captured by the second imaging unit 3a or 3b when the center of the article 11d reaches the intersection of the optical axes at the imaging timing of the first pattern.

  The reference site in the top image 12d is a substantially spindle-shaped major axis and minor axis formed by a horizontal section. Hereinafter, the length of the long axis in the top image 12d is referred to as “L1a”. Further, the length of the short axis in the top image 12d is referred to as “L1b”. The reference portion in the side image 13d in the long axis direction is the width (long axis) of the vertical cross section that is a spindle shape, and the width is referred to as “L2a”. The reference portion in the side image 14d in the short axis direction is the width (short axis) of the vertical cross section that is substantially circular, and the length of the width is referred to as “L2b”. Note that the side images 13 and 14d may include a measurement site 15 with scratches, discoloration, dirt, and the like. As described above, the length of the measurement site 15 in the side image is “L3”, and the length of the measurement site in the actual article 11d is “X”.

  The major axis of the horizontal cross section that is a spindle shape when the article 11d is viewed from above and the width of the vertical section when the article 11d is viewed from the side substantially perpendicular to the major axis direction have a corresponding relationship, and the actual length of the article 11d is long. Are substantially the same. That is, “L1a” and “L2a” are in a correspondence relationship, and their actual length is “La”. Further, the short axis of the horizontal section that is a spindle shape when the article 11d is viewed from above and the width of the vertical section when the article 11d is viewed from the side substantially perpendicular to the minor axis direction have a corresponding relationship, and the actual article 11d. The lengths at are substantially the same. That is, “L1b” and “L2b” are in a correspondence relationship, and their actual length is “Lb”.

  In the second embodiment, using the correspondence between “L1a” and “L2a” or the correspondence between “L1b” and “L2b”, the length “L3” of the measurement site confirmed in the side image. Is corrected, and the length “X” of the measurement site in the actual article 11d can be calculated. Specifically, when “L1a”, “L2a”, or “L1b” “L2b” is read as “L1” and “L2”, the correction processing in the first embodiment shown in FIG. 7 or FIG. 9 is applied. The length of the measurement site observed in the side image of the article 11d can be converted into the actual length. Note that the correction coefficient can be calculated more accurately by executing the correction process using the correspondence between “L1a” and “L2a” than using the correspondence between “L1b” and “L2b”. preferable.

  FIG. 12 is an explanatory diagram showing a relationship between another arrangement of the article that is the spindle and the imaging means. In FIG. 12, the article 11d is regulated at an angle of θ ° (−θ °) with respect to the transport direction, and is transported from upstream to downstream.

  FIG. 13A is an explanatory view showing a top image of an article (spindle body) imaged by the first imaging means 3d in the arrangement shown in FIG. FIG. 13B is an explanatory view showing a side image of the article (spindle body) imaged by the second imaging means 3a in the arrangement shown in FIG.

The length of the major axis in the top image 12e is “L1a”. The length of the width in the side image 13e is “L2a ′”. As shown in FIG. 12, the side image 13e is not a side image captured from a direction substantially perpendicular to the long axis, and therefore “L2a ′” is obtained when the image is captured from a direction approximately perpendicular to the long axis. The width of the side image is shorter than the length (L2a). “L2a ′” can be converted to “L2a” by the following Equation 6.
L2a = L2a ′ / cos (45 ° −θ °) (Expression 6)

Further, the length “L3 ′” of the measurement part 15 extending in the lateral direction observed in the side image 13e is longer than the length of the measurement part observed in the side image when imaged from a direction substantially perpendicular to the major axis. short. “L3 ′” can be converted to “L3” by Equation 7 below.
L3 = L3 ′ / cos (45 ° −θ °) (Expression 7)

  Since “L1a” and “L2a” have a corresponding relationship, the correction processing of the present invention is performed even when a side image is not captured from a direction substantially perpendicular to the long axis of the article 11d as shown in FIG. Can be applied. Specifically, when the correction processing shown in FIG. 7 is executed, first, “L1a” is measured as step S702. In step S703, the measured “L2a ′” is converted into “L2a” by the above-described equation 6. Next, in step S704, the measured “L3 ′” is converted into “L3” by the above-described Expression 7. Thereby, in step S705, the actual length of the measurement site observed in the side image can be calculated. Similarly, the correction process shown in FIG. 9 can be executed.

  As described above, in the second embodiment, the article to be inspected is not limited to an article having a substantially circular horizontal cross section viewed from above, and the horizontal cross section viewed from above has a spindle shape, an elliptical shape, The article may be a cylinder or the like, and the correction processing of the first embodiment can be applied to a conventional article inspection apparatus. That is, it is possible to determine the quality of the article by calculating the length of the measurement part in the side image using the correspondence between the reference part of the top image and the reference part of the side image.

  By the way, in the first embodiment, it is assumed that the article to be inspected has a substantially circular horizontal cross section, and the width is constant even when viewed from any side. However, the size of the article is determined by the width and height of the article perpendicular to the optical axis of the imaging unit, and strictly speaking, the size of the article may be different for each imaging unit, that is, depending on the orientation of the article. For example, when the article is an agricultural product or the like, the size and shape are different for each individual. For this reason, normally, a standard size is assumed according to the type of article, and the arrangement of the imaging means and the imaging timing are set based on the standard size.

  Conventionally, the difference in width and height depending on the orientation of the article has not been considered in particular and has been set by assuming that the same size is used for any imaging means. However, in the present invention, depending on the orientation of the article. It is also possible to reflect the difference in size on the imaging timing. In other words, when the size of the article in one direction is larger than the size in the other direction, the imaging unit that images the large direction is the imaging unit that advances the imaging timing or images the small direction. The imaging timing may be delayed so that an image with an appropriate size may be obtained, although the scale of the actual image varies depending on the image. This setting can be realized, for example, by independently controlling one imaging timing and the other imaging timing when there are two upstream second imaging means 3a.

  Hereinafter, specific numerical values will be described in the examples. In the following examples, a photoelectric sensor was used as the article detection means 4, and the rear end of the article 11 was detected. Further, an encoder is used as the transport distance measuring means 5. The conveying speed of the conveying means was 1000 mm / s, and the conveying distance per pulse of the encoder was 0.1 mm (that is, one pulse is 0.1 ms interval). In addition, grapefruit (large), Iyokan (middle), and Wenzhou orange (small) were used as the article 11. The lengths of these articles 11 were approximately 1500 pulses for grapefruit (large), approximately 1000 pulses for Iyokan (medium), and approximately 500 pulses for mandarin orange (small) according to the number of pulses of the encoder.

[Example 1]
FIG. 14 is a schematic configuration diagram of another article inspection apparatus according to the present invention. In Example 1, the article inspection apparatus shown in FIG. 14 was used. The apparatus of FIG. 14 has the same basic configuration as the apparatus of FIG. 1, but the article detection means 4 is arranged at the imaging position A of the standard article and the article detection signal input by the article detection means 4 is imaged. It is used as one of the timings. Each component in the apparatus of FIG. 14 is denoted by the same reference numerals as those in FIG.

  In the article inspection apparatus of Example 1, each imaging means 3 was arranged using grapefruit (large) as a standard product. That is, with the rear end of the grapefruit (large) reaching the imaging position A (= detection position), the grapefruit (large) is imaged clearly and appropriately in the screen of each of the second imaging means 3a and b. In order to make it possible, the optical axes of the second imaging means 3a and b are arranged so as to intersect at the center of grapefruit (large) (position of 750 pulses from the imaging position A). Further, the first imaging means 3d is positioned above the center of the grapefruit (large) at the imaging position A (the intersection of the optical axes of the second imaging means 3a and b) so that the optical axis passes through the center of the grapefruit (large). Arranged.

  First, in order to image the imaging means (mode 1) for imaging grapefruit (large), the imaging timing (mode 2) for imaging Iyokan (medium), and Wenzhou orange (small) to the control means 6. The imaging timing (mode 3) was set. Since grapefruit (large) is a standard product, mode 1 which is its imaging timing is set so that imaging is performed when the rear end reaches the imaging position A (= detection position) for all imaging means. (As described above, when each imaging means is equipped with illumination, each imaging means sequentially images in order to prevent backlighting). Since Iyokan (medium) is 500 pulses smaller than the grapefruit (large), the second imaging means 3a upstream is the imaging position of the second imaging means 3a, as in the case of grapefruit (large). The image is picked up when A (= detection position) is reached. For the first image pickup means 3d, the center of Iyokan (medium) is the center position of the grapefruit (large) at the image pickup position A (the intersection of the optical axes of the image pickup means). ) After 250 pulses (25 ms later), and for the downstream second imaging means 3b, after 500 pulses (50 ms) the front end reaches the same position as the front end of the grapefruit (large) at the imaging position A. The camera was set to take an image in (after). Since Wenzhou mandarin orange (small) is 1000 pulses smaller than grapefruit (large), mode 3 which is the imaging timing of the upstream second imaging means 3a is the same as the grapefruit (large), and the rear end is the imaging position. The image is picked up when A (= detection position) is reached. For the first image pickup means 3d, the center of Wenzhou mandarin orange (small) is the center position of the grapefruit (large) at the image pickup position A (the intersection of the optical axes of the image pickup means). ), And the downstream second imaging means 3b reaches the same position as the front end of the grapefruit (large) at the imaging position A for the downstream second imaging means 3b. It was set to take an image after 1000 pulses (after 100 ms). Table 1 is a list of imaging timings of the first embodiment.

以上のように撮像タイミングを設定した物品検査装置１において、グレープフルーツ（大）を検査する場合、撮像タイミングをモード１に設定し、搬送手段によってグレープフルーツ（大）を順次一列に搬送させる。グレープフルーツ（大）の前端部が、光電センサ４が配置されている位置まで到達すると、光電センサの光がグレープフルーツ（大）によって遮光されて、光電センサがＯＦＦ状態となる。その約１５００パルス後、グレープフルーツ（大）が通過することによって、再び光電センサがＯＮ状態となり、物品の後端部を検出し、制御装置６に検出信号が入力される。制御装置６は、検出信号を受けて、上流の第２撮像手段３ａ、第１撮像手段３ｄ及び下流の第２撮像手段３ｂの全てに対し、撮像信号を出力し、各撮像手段は、グレープフルーツ（大）を撮像し、撮像された画像を制御装置６へ出力する。制御手段６は、入力された画像に基づいて所定の検査を行う。

In the article inspection apparatus 1 in which the imaging timing is set as described above, when inspecting the grapefruit (large), the imaging timing is set to mode 1, and the grapefruit (large) is sequentially conveyed in a line by the conveying means. When the front end of the grapefruit (large) reaches the position where the photoelectric sensor 4 is disposed, the light from the photoelectric sensor is blocked by the grapefruit (large), and the photoelectric sensor is turned off. After about 1500 pulses, when the grapefruit (large) passes, the photoelectric sensor is turned on again, the rear end of the article is detected, and a detection signal is input to the control device 6. Upon receiving the detection signal, the control device 6 outputs an imaging signal to all of the upstream second imaging means 3a, the first imaging means 3d, and the downstream second imaging means 3b. Large) and outputs the captured image to the control device 6. The control means 6 performs a predetermined inspection based on the input image.

  Next, when inspecting Iyokan (middle), the imaging timing is set to mode 2, and the Iyokan (middle) is sequentially conveyed in a line by the conveying means. When the front end of Iyokan (medium) reaches the position where the photoelectric sensor 4 is arranged, the light of the photoelectric sensor is blocked by the Iyokan (middle), and the photoelectric sensor is turned off. About 1000 pulses later, when Iyokan (medium) passes, the photoelectric sensor is turned on again, the rear end of the article is detected, and a detection signal is input to the control device 6. The control device 6 receives the detection signal and outputs an imaging signal to the upstream second imaging means 3a. Thereafter, when a pulse signal of 250 pulses is input from the encoder 5, an imaging signal is output to the first imaging means 3d. Further, when a pulse signal of 250 pulses (500 pulses from the detection position D) is input from the encoder 5, an imaging signal is output to the second imaging means 3b downstream. The image of Iyokan (medium) imaged by each imaging means is input to the control device 6, and the control means 6 performs a predetermined inspection based on the input image.

  Also, when inspecting mandarin oranges (small), the imaging timing is set to mode 3, and the mandarin oranges (small) are sequentially conveyed in a line by the conveying means. When the front end portion of the mandarin orange (small) reaches the position where the photoelectric sensor 4 is disposed, the light of the photoelectric sensor is blocked by the mandarin orange (small), and the photoelectric sensor is turned off. After about 500 pulses, when the mandarin orange (small) passes, the photoelectric sensor is turned on again, the rear end of the article is detected, and a detection signal is input to the control device 6. The control device 6 receives the detection signal and outputs an imaging signal to the upstream second imaging means 3a. Thereafter, when a pulse signal of 500 pulses is input from the encoder 5, an imaging signal is output to the first imaging means 3d. Further, when a pulse signal of 500 pulses (1000 pulses from the detection position D) is input from the encoder 5, the imaging signal is output to the second imaging means 3b downstream. An image of Wenzhou mandarin orange (small) imaged by each imaging means is input to the control device 6, and the control means 6 performs a predetermined inspection based on the input image.

  In the article inspection apparatus 1 of Example 1, since the largest article was used as a standard product, the other articles were the same as or smaller than the standard product, so the imaging timing of the upstream second imaging means could be made the same. On the other hand, for an article smaller than the standard, an image of an appropriate size could be obtained by changing the imaging timing of the downstream second imaging unit and first imaging unit 3d late. Further, since the detection signal is one of the imaging timings, it is not necessary to count the number of pulses from the encoder, and high-speed processing is possible. In Embodiment 1, the modes 1 to 3 are switched by the operator, but may be switched by other means. For example, the number of pulses from the OFF state to the ON state of the photoelectric sensor may be counted by an encoder, and modes 1 to 3 may be automatically switched according to the number of pulses. In the first embodiment, the imaging timing of the upstream second imaging unit is the same for each article, but may be changed. For example, in order to inspect the surface scratches in detail, when it is desired to enlarge the image of the smallest mandarin orange (small), it may be imaged upstream of the imaging position. In this case, the imaging signal may be generated while the photoelectric sensor is in the OFF state (for example, 600 pulses after the OFF state).

[Example 2]
As shown in FIG. 1, the article inspection apparatus 1 according to the second embodiment has a photoelectric sensor disposed upstream of the conveyance path, detects an article by the photoelectric sensor, and then counts the number of pulses from the encoder to obtain an imaging timing. To do. In the article inspection apparatus 1 of Example 2, each imaging means 3 was arranged with Iyokan (medium) as a standard product. That is, in the state where the rear end of Iyokan (medium) has reached the imaging position A, the Iyokan (middle) is arranged so that it can be clearly imaged with an appropriate size in the screen of each imaging means. Further, the first imaging means 3d is arranged above the center of Iyokan (medium) at the imaging position A (position of 500 pulses from the imaging position A). In the article inspection apparatus 1 of Example 2, the distance from the photoelectric sensor 4 to the imaging position A was 3000 pulses.

  First, in order to image the imaging means (mode 1) for imaging grapefruit (large), the imaging timing (mode 2) for imaging Iyokan (medium), and Wenzhou orange (small) to the control means 6. The imaging timing (mode 3) was set. Grapefruit (large) is 500 pulses larger than the standard Iyokan (medium), so mode 1 as its imaging timing is the same as Iyokan (middle) in the imaging position for the second imaging means 3a upstream. When the rear end part reaches A, that is, after 3000 pulses from the detection position D, and for the first imaging means, the center of the grapefruit (large) reaches the center position of Iyokan (medium) at the imaging position A That is, after 2750 pulses from the detection position D, the downstream second imaging means 3b is set to take an image after 2500 pulses when the front end reaches the same position as the front end of Iyokan (medium) at the imaging position A. did. Since Iyokan (medium) is a standard product, mode 2 which is the imaging timing thereof is imaged for all imaging means when the rear end reaches the imaging position A, that is, after 3000 pulses from the detection position D. Was set as follows. Since Wenzhou mandarin orange (small) is 500 pulses smaller than Iyokan (middle), mode 3 which is the imaging timing is the same as Iyokan (middle) for the second imaging means 3a upstream. When reaching the imaging position A, that is, after 3000 pulses from the detection position D, for the first imaging means, 3250 pulses at which the center of Wenzhou orange (small) reaches the center position of Iyokan (medium) at the imaging position A The downstream second imaging means 3b was set to capture after 3500 pulses when the front end of the mandarin orange (small) reached the same position as the front end of Iyokan (middle) at the imaging position A. . Table 2 is a list of imaging timings of the second embodiment.

以上のように撮像タイミングを設定した物品検査装置１において、グレープフルーツ（大）を検査する場合、撮像タイミングをモード１に設定し、搬送手段によってグレープフルーツ（大）を順次一列に搬送させる。グレープフルーツ（大）の前端部が、光電センサ４が配置されている位置まで到達すると、光電センサの光がグレープフルーツ（大）によって遮光されて、光電センサがＯＦＦ状態となる。その約１５００パルス後、グレープフルーツ（大）が通過することによって、再び光電センサがＯＮ状態となり、物品の後端部を検出し、制御装置６に検出信号が入力される。制御装置６は、検出信号の入力後、エンコーダ５からのパルス数をカウントし、検出信号の入力から２５００パルス後、最初に下流の第２撮像手段３ｂに対し撮像信号を出力し、下流の第２撮像手段３ｂは、グレープフルーツ（大）の前面を撮像して、その画像を制御装置６へ出力する。さらに２５０パルス後（検出信号の入力から２７５０パルス後）、制御装置６は、第１撮像手段に対し撮像信号を出力し、第１撮像手段は、グレープフルーツ（大）の上面を撮像して、その画像を制御装置６へ出力する。最後に、さらに２５０パルス後（検出信号の入力から３０００パルス後）、制御装置６は、上流の第２撮像手段３ａに対し撮像信号を出力し、上流の第２撮像手段３ａは、グレープフルーツ（大）の後面を撮像して、その画像を制御装置６へ出力する。制御手段６は、入力された画像に基づいて所定の検査を行う。

In the article inspection apparatus 1 in which the imaging timing is set as described above, when inspecting the grapefruit (large), the imaging timing is set to mode 1, and the grapefruit (large) is sequentially conveyed in a line by the conveying means. When the front end of the grapefruit (large) reaches the position where the photoelectric sensor 4 is disposed, the light from the photoelectric sensor is blocked by the grapefruit (large), and the photoelectric sensor is turned off. After about 1500 pulses, when the grapefruit (large) passes, the photoelectric sensor is turned on again, the rear end of the article is detected, and a detection signal is input to the control device 6. The control device 6 counts the number of pulses from the encoder 5 after inputting the detection signal, and after 2500 pulses from the input of the detection signal, first outputs the imaging signal to the downstream second imaging means 3b, The 2 imaging means 3b images the front surface of the grapefruit (large) and outputs the image to the control device 6. After 250 pulses (after 2750 pulses from the input of the detection signal), the control device 6 outputs an imaging signal to the first imaging unit, and the first imaging unit images the upper surface of the grapefruit (large), The image is output to the control device 6. Finally, after another 250 pulses (3000 pulses after the detection signal is input), the control device 6 outputs an imaging signal to the upstream second imaging means 3a, and the upstream second imaging means 3a ) And the image is output to the control device 6. The control means 6 performs a predetermined inspection based on the input image.

  Next, when inspecting Iyokan (middle), the imaging timing is set to mode 2, and the Iyokan (middle) is sequentially conveyed in a line by the conveying means. When the rear end of Iyokan (medium) is detected by the photoelectric sensor 4 and a detection signal is input to the control device 6, the control device 6 counts the number of pulses from the encoder 5, and the number of pulses is 3000 pulses. At that time, imaging signals are sent to all the imaging means, and an image of Iyokan (medium) is obtained.

  Also, when inspecting mandarin oranges (small), the imaging timing is set to mode 3, and the mandarin oranges (small) are sequentially conveyed in a line by the conveying means. When the photoelectric sensor 4 detects the rear end of Wenzhou mandarin orange (small) and a detection signal is input to the control device 6, the control device 6 counts the number of pulses from the encoder 5, and from the detection signal input When the number of pulses reaches 3000, an imaging signal is output to the upstream second imaging means 3a. Thereafter, when the number of pulses reaches 3250 pulses, an imaging signal is output to the first imaging unit, and when the number of pulses reaches 3500 pulses, an imaging signal is output to the downstream second imaging unit 3b. An image of Wenzhou mandarin orange (small) imaged by each imaging means is input to the control device 6, and the control means 6 performs a predetermined inspection based on the input image.

  In the article inspection apparatus 1 of the second embodiment, in the grapefruit (large) that is larger than the standard product, the imaging timing of the downstream second imaging unit and the first imaging unit is earlier than the imaging timing (3000 pulses) of the standard product. By setting, an image of an appropriate size could be obtained. In addition, for Wenzhou mandarin orange (small) smaller than the standard, an image of an appropriate size could be obtained by setting the imaging timing of the downstream second imaging means and the first imaging means late. In the second embodiment, the mode 1 to 3 may be switched by the operator or by other means. Also in the second embodiment, the imaging timing of the upstream second imaging means is the same for each article, but it may be changed.

[Example 3]
In the third embodiment, when the photoelectric sensor 4 detects an article, it also has a function of measuring the size thereof, and reads out a mode registered in the control device 6 in advance according to the detected size of the article. In this embodiment, the imaging timing is automatically changed. The basic configuration of the article inspection apparatus 1 is the same as that of the second embodiment.

  In the control means 6, as shown in Table 1 or 2, the imaging timing for each article is set as each mode. Furthermore, in this embodiment, the correspondence between the size of the article and the mode is registered in the control means 6. Table 3 is an example.

実施例３の物品検査装置１において、搬送手段２によって搬送される物品は、光電センサ４によって、そのサイズが計測される。すなわち、制御手段６は、物品１１の前端部が光電センサ４の位置に到達して、光電センサ４がＯＦＦ状態となった時点から、物品１１の後端部が通過して光電センサ４がＯＮ状態となるまでのパルス数をエンコーダ５でカウントし、物品１１の長さを計測する。その計測結果が、表３に示す何れの範囲に属するのか判断し、その範囲に対応するモードで各撮像手段に対し撮像信号を出力する。実施例３においては、選択されたモード及び計測された物品の長さも、物品の検査において重要な情報であるから、選択されたモード又は計測結果を画像と関連付けて記憶したり、表示したり、検査において利用したりすることが好ましい。

In the article inspection apparatus 1 according to the third embodiment, the size of the article conveyed by the conveying unit 2 is measured by the photoelectric sensor 4. That is, the control means 6 is configured such that when the front end of the article 11 reaches the position of the photoelectric sensor 4 and the photoelectric sensor 4 is turned off, the rear end of the article 11 passes and the photoelectric sensor 4 is turned on. The number of pulses until the state is reached is counted by the encoder 5, and the length of the article 11 is measured. It is determined to which range shown in Table 3 the measurement result belongs, and an imaging signal is output to each imaging means in a mode corresponding to that range. In Example 3, since the selected mode and the measured length of the article are also important information in the inspection of the article, the selected mode or the measurement result is stored in association with the image, displayed, It is preferable to use in inspection.

  In the article inspection apparatus 1 according to the third embodiment, since the mode is changed based on the measurement result of the article size, it is not necessary to change the setting by the operator. An image of an appropriate size can be obtained even for an article (mainly agricultural product) having a large size variation within the variety. In Example 3, the size of the article was measured using the photoelectric sensor 4 for detecting the article, but a sensor for measuring the size of the article may be provided separately.

[Example 4]
Example 4 is an example which shows the length of the reference | standard site | part of each article imaged at the imaging timing of Example 1. FIG. In the control means 6, as shown in Table 1 or Table 2, the imaging timing for each article is set as each mode. Table 4 is an example showing the relationship between the actual length of the reference portion of each article and the length of the reference portion in the top image and side image of each article imaged at the set imaging timing.

実施例４において、グレープフルーツの外観の測定結果を例にすると、上面画像における基準部位の長さＬ１は、５４０ピクセルであり、側面画像（１）における基準部位の長さＬ２は、４９５ピクセルであり、側面画像（２）における基準部位の長さＬ２は、４７２ピクセルであった。さらに、側面画像（１）には、測定部位である傷が認められ、測定部位の長さＬ３は、３０ピクセルであった。

In Example 4, when the measurement result of the appearance of the grapefruit is taken as an example, the length L1 of the reference portion in the top image is 540 pixels, and the length L2 of the reference portion in the side image (1) is 495 pixels. The length L2 of the reference portion in the side image (2) was 472 pixels. Further, in the side image (1), a wound as a measurement site was recognized, and the length L3 of the measurement site was 30 pixels.

  First, in the case of grapefruit, the first coefficient k for correcting the length in the top image to the actual length was set to 0.28 mm / pixel. For this reason, the actual length L of the reference portion was calculated as 0.28 mm / pixel × 540 pixels = 151.2 mm from the length L1 (540 pixels) of the reference portion in the top image. Since the actual length L (the diameter of the horizontal section) of the reference part of grapefruit was 150 mm, the calculation result by the first coefficient k was almost the same as the actual size. Note that, by measuring the actual length L, the first coefficient k can also be obtained by calculation (150 mm ÷ 540 pixels).

The second coefficient j for correcting the length L3 of the measurement site to the actual length X is calculated as follows using the above-described equation 4.
j = k × (L1 / L2) = 0.28 × (540 ÷ 495)
= 0.31 mm / pixel (however, the third decimal place is rounded off)
Furthermore, the actual length X of the measurement site is calculated as follows using the above-described Expression 5.
X = j × L3 = 0.31 × 30 = 9.3 mm

  Taking the measurement result of the appearance of Iyokan as an example, the length L1 of the reference portion in the top image is 397 pixels, the length L2 of the reference portion in the side image (1) is 485 pixels, The length L2 of the reference part in the image (2) was 482 pixels. Further, in the side image (1), a wound as a measurement site was recognized, and the length L3 of the measurement site was 20 pixels.

  In the case of Iyokan, the first coefficient k was set to 0.25 mm / pixel. For this reason, the actual length L of the reference portion was calculated as 0.25 mm / pixel × 397 pixels = 99.25 mm using the length L1 of the reference portion in the top image. The actual length L (horizontal cross-sectional diameter) of the reference site of Iyokan was 100 mm, which almost coincided with the calculation result.

The second coefficient j for correcting the length L3 of the measurement site to the actual length X is calculated as follows using the above-described equation 4.
j = k × (L1 / L2) = 0.25 × (397 ÷ 485)
= 0.20 mm / pixel (however, rounded off to the second decimal place)
Furthermore, the actual length X of the measurement site is calculated as follows using the above-described Expression 5.
X = j × L3 = 0.20 × 20 = 4.0 mm

  Taking the measurement result of the appearance of Wenzhou oranges as an example, the length L1 of the reference portion in the top image is 198 pixels, the length L2 of the reference portion in the side image (1) is 501 pixels, The length L2 of the reference part in the image (2) was 490 pixels. Further, in the side image (1), a wound as a measurement site was recognized, and the length L3 of the measurement site was 15 pixels.

  In the case of Wenzhou oranges, the first coefficient k was set to 0.25 mm / pixel. For this reason, the actual length L of the reference portion was calculated as 0.25 mm / pixel × 198 pixels = 49.5 mm using the length L1 of the reference portion in the top image. The actual length L (horizontal cross section diameter) of the reference part of Wenzhou mandarin orange was 50 mm, which almost coincided with the calculation result.

The second coefficient j for correcting the length L3 of the measurement site to the actual length X is calculated as follows using the above-described equation 4.
j = k × (L1 / L2) = 0.25 × (198 ÷ 501)
= 0.10mm / pixel (however, rounded off to the third decimal place)
Furthermore, the actual length X of the measurement site is calculated as follows using the above-described Expression 5.
X = j × L3 = 0.10 × 15 = 1.5 mm

  In addition, in the above Examples 1-4, although the apparatus which test | inspects agricultural products was demonstrated, the range of this invention is not limited to this structure, It can utilize in the articles | goods which require the test | inspection of another external appearance. It is. In the above description, the conveying path is exemplified as a straight line. However, the present invention is not limited to such a configuration. For example, a so-called rotary conveying unit that conveys an article in the circumferential direction by a rotating body is used. The present invention can be applied even when used.

DESCRIPTION OF SYMBOLS 1 Article inspection apparatus 2 Conveyance means 3a Upstream 2nd imaging means 3b Downstream second imaging means 3c Right side second imaging means 3d First imaging means 4 Article detection means 5 Conveyance distance measurement means 6 Control means 11a, 11b, 11c Articles 12a, 12b, 12c Top images 13a, 13b, 13c Side images 14a, 14b, 14c imaged from one direction Side images 15a, 15b, 15c imaged from other directions Measurement site 16a, 16b, 16c Measurement site L1 First length L2 of the reference part in the top image Second length L3 of the reference part in the side image Third length L of the measurement part in the side image Actual length X of the reference part in the top image or the side image Actual length of measurement site

Claims (10)

An article inspection apparatus for inspecting the appearance of an article,
Conveying means for conveying the article, first imaging means for imaging the article being conveyed by the conveying means from above, and second imaging for imaging the article being conveyed by the conveying means from the side An imaging means; and a control means for controlling the first imaging means and the second imaging means,
The control means includes
Obtaining a top image of the article imaged by the first imaging means and a side image of the article imaged by the second imaging means;
It is a part in each acquired image, and a part having a corresponding relationship in which the actual lengths of articles are substantially the same is set as a reference part,
Measure the apparent length of the reference part in the acquired top image as the first length,
Measure the apparent length of the reference part in the acquired side image as a second length,
Measure the apparent length of the measurement site in the acquired side image as the third length,
The article inspection apparatus, wherein the third length is converted into an apparent length in the upper surface image based on the correspondence relationship between the measured first length and second length. The control means includes
Converting the first length to an actual length based on a predetermined first coefficient;
Calculating a second coefficient based on the correspondence between the second length and the converted actual length;
2. The article inspection apparatus according to claim 1, wherein the third length is converted into a unit of an actual length based on the calculated second coefficient. The article has a substantially circular horizontal cross section viewed from the imaging direction of the first imaging means,
The reference portion is a diameter of a horizontal section that is substantially circular,
The first length is a length of a diameter of a horizontal section of the article in the acquired top image,
The article inspection apparatus according to claim 1, wherein the second length is a length of an article width in the acquired side image. The second imaging unit includes an imaging unit that images the article being conveyed by the conveying unit from the upstream side in the conveyance direction, and an imaging unit that images from the downstream side,
The conveying means conveys a plurality of types of articles having different sizes and shapes,
The control means can independently set the imaging timing of the upstream second imaging means and the imaging timing of the downstream second imaging means, and depends on the size, shape or type of the article to be conveyed A combination of a plurality of different imaging timings, a first setting for simultaneously imaging the second upstream imaging unit and the second downstream imaging unit, and the second upstream imaging unit and the downstream second imaging unit. The article inspection apparatus according to any one of claims 1 to 3, further comprising a second setting for imaging the second imaging unit at a different imaging timing. The second setting is:
When the article to be imaged with the second setting is smaller than the article to be imaged with the first setting, the upstream second imaging means is imaged first, and the article is conveyed by a predetermined distance. And then imaging the downstream second imaging means,
When the article to be imaged with the second setting is larger than the article to be imaged with the first setting, the second imaging means on the downstream side is imaged first, and the article is conveyed by a predetermined distance. The article inspection apparatus according to claim 4, wherein the upstream second imaging means is imaged. The article has a shape in which a horizontal section viewed from the imaging direction of the first imaging means has a major axis and a minor axis,
The conveying means regulates the orientation of the article so that the major axis or minor axis of the article is substantially perpendicular to the imaging direction of the second imaging means;
The article inspection apparatus according to claim 1, wherein the reference portion is a major axis or a minor axis of the article. The article is conveyed by the conveying means, the article is imaged from the upper side by the first imaging means, the article is imaged from the side by the second imaging means, and a top image and a side image of the article are obtained, An article inspection method for inspecting the appearance of an article based on the acquired top image and side image,
A part in each acquired image, and a part having a corresponding relationship in which the actual lengths of articles are substantially the same is set as a reference part,
Measure the apparent length of the reference part in the acquired top image as the first length,
Measure the apparent length of the reference part in the acquired side image as a second length,
Measure the apparent length of the measurement site in the acquired side image as the third length,
An article inspection method, wherein the third length is converted into an apparent length in the top image based on the correspondence relationship between the measured first length and second length. Converting the first length to an actual length based on a predetermined first coefficient;
Calculating a second coefficient based on the correspondence between the second length and the converted actual length;
The article inspection method according to claim 7, wherein the third length is converted into an actual length unit based on the calculated second coefficient. The article has a substantially circular horizontal cross section viewed from the imaging direction of the first imaging means,
The reference portion is a diameter of a horizontal section that is substantially circular,
The first length is the length of the diameter of the horizontal section of the article in the acquired top image,
9. The article inspection method according to claim 7, wherein the second length is a length of an article in the acquired side image. The second imaging unit includes an imaging unit that images the article being conveyed by the conveying unit from the upstream side in the conveyance direction, and an imaging unit that images from the downstream side,
According to the size or type of the article to be conveyed, the upstream second imaging means is set by independently setting the imaging timing of the upstream second imaging means and the downstream second imaging means. 10. The article inspection method according to claim 7, wherein a plurality of side images of the article are acquired by imaging the downstream second imaging means at different imaging timings.

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