JP2005315868A - Wide article inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection method capable of appropriately and speedily inspecting wide articles, even if the position (height) of the inspection surface of a wide article is changed, when the inspection zones of the most adjacent sensor cameras are superimposed on each other by a desired width, in the inspection surface of the wide article for inspecting the wide article through the use of a plurality of sensor cameras. <P>SOLUTION: At the inspection of the wide article 3 through the use of the plurality of sensor cameras 1 and 2, the inspection zone L1 of the adjacent sensor camera 1 and the inspection zone L2 of the sensor camera 2 are set, in such a way as to be superimposed on each other by a desired width N in the inspection surface 3a of the wide article. The center part in the superimposed inspection zones is irradiated with a thin beam of light 6 of a color, which is different from a color originally present in the wide article 3. On the basis of information of the thin beam of light 6 detected by the sensor cameras 1 and 2, the actual range of the superposition of the inspection zones in the inspection surface 3a of the wide article is computed, and superimposed inspection information is processed appropriately and the wide article 3 is inspected. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for inspecting wide articles.

  Conventionally, in the process of continuously or intermittently transporting various articles that are continuous strips or discontinuous non-strips, they are placed on the inspection surface of the article (usually the top surface of the article). By inspecting the inspection surface of an article using a sensor camera such as a CCD line sensor camera, a 3 CCD color line sensor camera, or a CCD area sensor camera, for example, wrinkles, dirt, chipping, different colors, colors There are already many processes that check the presence and size of defects, defects, inconveniences, etc., such as unevenness, determine the location of these defects, or determine the color tone and color distribution of articles, for example. Has been put to practical use in the field of

  Furthermore, when the width of the article (the width in the direction intersecting the transport direction) is wide, that is, when inspecting a wide article, if inspection is performed with one sensor camera, the inspection accuracy deteriorates. For example, “defect inspection method” (Japanese Patent Laid-Open No. 4-166649), “image display method for printed matter inspection device” (Japanese Patent Laid-Open No. 8-281920), “image display method and device” (Japanese Patent Laid-Open No. 2001-337042) ) Etc., a configuration in which a plurality of sensor cameras are provided side by side in the width direction of a wide article and the inspection is performed in a divided manner is already known. In addition, a technique for combining and displaying on one display has already been established.

  By the way, when a plurality of sensor cameras are provided, the inspection area (field of view) between adjacent sensor cameras in the width direction of the wide article is set as the wide article as disclosed in Japanese Patent Laid-Open No. 2001-337042. Since it is extremely difficult or complicated to set the inspection surface so as to match with no excess or deficiency, generally, as disclosed in the above-mentioned JP-A-8-281920. The inspection area between adjacent sensor cameras is set to overlap the desired width on the inspection surface of the wide article, and the inspection area is adopted. Is set to overlap the desired width on the inspection surface of the wide article, since the inspection information of the overlapped portion is obtained from each sensor camera, the detected information and all the detected inspection information are wide. Stuff In order to match the entity, for example, the information is synthesized so as to obtain the average value of the overlapping information, or the overlapping information is compared, for example, and the information having a large value is preferentially adopted. There is a need to perform information processing (information organization) such as selecting information or preferentially adopting one of predetermined information.

  Thus, in order to perform the information processing as described above, it is essential to accurately calculate the overlap width of the inspection area between adjacent sensor cameras. If the relative positional relationship between the wide article and the sensor camera is assumed, If it is not changed, the preset overlap width can be easily calculated by using a means such as a test of a wide article having a sample of defects, for example. Since there is no need to change, there is no special problem, but when the relative positional relationship between the wide article and the sensor camera changes, the preset overlap width and the actual overlap range are different, so the preset setting If the value calculated in (1) is used regularly, there is a problem that the processed information does not match the substance of the wide article.

  That is, for example, as illustrated in FIGS. 4, 5, and 6, the inspection areas L 1 and L 2 of the pair of left and right sensor cameras 1 and 2 (both illustrated examples are line sensor cameras) In the case of overlapping in advance by a desired width N (substantially, the number of pixels corresponding to the desired width N), the inspection surface 3a of the wide article 3 passes the position indicated by the line a. Sometimes, there is no problem because the preset overlap width N and the actual overlap range (width) N coincide with each other, but when the inspection surface 3a of the wide article 3 passes the position indicated by the line b, the actual overlap range M and M ≠ N (M <N when passing a position higher than a preset height as shown in the example, but M> N when passing a position lower than a preset height. N), the value of the overlap width N calculated in advance is If, for example, the information processing is performed, the width of the wide article by the processed information is different from the width of the actual wide article, or the size of the defect by the processed information is the size of the actual defect. Or, for example, the position of the defect due to the processed information is different from the actual position of the defect, and the processed information does not match the substance of the wide article. In the figure, reference numeral 4 denotes an illumination member that illuminates the inspection surface of a wide article. Further, the information processing mechanism for processing the inspection information sent from each sensor camera is omitted for convenience.

  As an example of a means for solving such a problem, as disclosed in, for example, “video signal synthesizer” (Japanese Patent Laid-Open No. 2000-349988), the relative distance between the inspection surface of a wide article and a sensor camera is measured, Based on the information on the relative distance, the overlapping range detection means for calculating the overlapping range between the adjacent sensor cameras is provided at the front of the sensor camera (upper side in the wide article conveying direction), and the displacement of the inspection surface of the wide article is detected. The resulting overlapping range variation between adjacent sensor cameras is calculated by the overlapping range detecting means, and based on the calculated overlapping range value, the inspection information between adjacent sensor cameras is corrected and combined. Solutions have been proposed.

The solution means that the inspection surface of the wide article to be inspected is substantially flat, such as when inspecting a plurality of types of steel plates having different thicknesses separately, and each of them is displaced stepwise individually. For example, the measurement of the relative distance between the inspection surface of the wide article and the sensor camera, and the calculation of the overlapping range between adjacent sensor cameras based on the information on the relative distance are performed every time the wide article to be inspected is replaced. There is almost no risk of errors occurring between the actual overlapping range between adjacent sensor cameras and the calculated overlapping range calculated by the overlapping range detection means, so that the corresponding effect is achieved. It is expected.
JP-A-8-281920 JP 2000-349988 A

  However, in the case where the above-described solution is adopted, the measuring device that measures the relative distance between the inspection surface of the wide article and the sensor camera, and the overlapping range of adjacent sensor cameras based on the signal of the measuring device. As a result, it is not only difficult to increase the required equipment cost as a whole, but also, for example, when inspecting veneer veneers with blows and undulations, When the inspection surface is non-planar, there is a defect that causes an error in the calculation overlap range calculated by the overlap range detection means and the actual overlap range, and the inspection surface is displaced every moment. In order to accurately calculate the overlapping range of the inspection areas between adjacent sensor cameras in the camera, it is necessary to repeat the calculation from moment to moment. If the calculation is delayed, the calculated overlapping range and the actual overlapping range Is always the problem of conflict occurs, as a result, such as not being forced to relatively slow setting the conveying speed of the wide article, there is a bad influence defect in the inspection efficiency.

  The present invention was developed to eliminate the disadvantages, defects and drawbacks of the conventional inspection method. Specifically, when inspecting a wide article using a plurality of sensor cameras, adjacent sensor cameras are used. The inspection area between the two is set so that a desired width is overlapped on the inspection surface of the wide article, and a thin light beam having a color different from the color originally present in the wide article is placed in the center of the overlapped inspection area. Based on the information of the thin light beam detected by each sensor camera, the overlap area of the actual inspection area on the inspection surface of the wide article is calculated, and the inspection information is processed appropriately by overlapping inspection information. And a method for inspecting a wide article (Claim 1), wherein the inspection surface of the wide article is irradiated with a thin light beam in a line extending in the same direction as the conveying direction of the wide article. Method for inspecting wide article according to Item 1 ( Claim 2) and the method for inspecting a wide article according to claim 1 wherein the inspection surface of the wide article is irradiated with a narrow light beam in a spot form (Claim 3), and the thin light beam to be irradiated is a laser. 4. A method for inspecting a wide article according to claim 1 or claim 2 or claim 3 (claim 4) which is a light beam, and a color sensor camera, or claim 1 or claim 2 or claim 3 or claim 4. A wide article inspection method according to claim 5 is proposed.

  According to the method for inspecting a wide article according to the present invention, the inspection surface of a wide article having a substantially flat inspection surface is included, including the case where the thickness changes individually in stages, with a simpler and less expensive configuration than the conventional inspection method. Of course, it is possible to accurately inspect even wide articles with flare and undulations, and the relative distance between the inspection surface of the wide article and the sensor camera. Based on the above, since the complicated calculation for calculating the overlapping range of the inspection areas of the adjacent sensor cameras is unnecessary, it is possible to perform the inspection more efficiently than in the past.

  Hereinafter, the present invention will be described in more detail based on an example of the embodiment illustrated in the drawings. However, the illustrated embodiment avoids redundancy of the description, and for the sake of convenience in describing the basic configuration. Similar to the description of the prior art, the simplest form using a pair of left and right sensor cameras is given, and does not necessarily show the best form. For example, to improve inspection accuracy As described above, if necessary, there is a preferable form other than the form of the illustrated embodiment, such as adding a sensor camera or a lighting member, and the present invention can be appropriately implemented. For the same convenience, members having the same configuration as the configuration of the drawings used in the description of the prior art are given the same reference numerals, and redundant description is omitted.

  The method for inspecting a wide article according to the present invention includes, for example, the above-described sensor cameras when inspecting a wide article 3 using a pair of left and right sensor cameras 1 and 2 as illustrated in FIGS. The inspection areas L1 and L2 of 1 and 2 are set so as to overlap each other by the desired width N on the inspection surface 3a of the wide article 3, and the center part in the overlapped inspection area (the example shown in the figure is overlapped). A light beam having a color different from the color originally present in the wide article 3 (in the illustrated example, in the same direction as the conveyance direction of the wide article). A linear light beam 6), and the overlapping range of the actual inspection area on the inspection surface 3a of the wide article 3 is determined based on the information of the thin light beam 6 detected by the sensor cameras 1 and 2. Calculate and process duplicate inspection information properly And performs inspection Te. In the figure, reference numeral 7 denotes an information processing mechanism for processing the inspection information sent from each of the sensor cameras 1 and 2 and transmitting it to the inspection mechanism (not shown) in the next process.

  The calculation of the overlapping range will be described in more detail. For example, at the position (height) indicated by the line a, the inspection areas L1 and L2 of the sensor cameras 1 and 2 are set in advance by a desired width N (substantially 2), when the inspection surface 3a of the wide article 3 passes through the position indicated by the line a, the right side sensor camera in the rear explanatory view of FIG. 1 detects the thin light beam 6 at a position N1 from the left end of the inspection area, and the left sensor camera 2 detects the light beam 6 at a position N2 from the right end of the inspection area. Since the thin light beam 6 is detected, and it is obvious that the thin light beams 6 detected by the sensor cameras 1 and 2 are at the same position, the overlapping range of the actual inspection area is N1 + N2 = N, the preset overlap width N Matching that is, without performing such special complicated operation, easily turn out immediately.

  Further, for example, when the thickness of the wide article 3 is changed, or when the wide article 3 is blown or wavy, the inspection surface 3a of the wide article 3 passes the position indicated by the line b. Sometimes the right sensor camera 1 detects the thin light beam 6 at a position M1 inside from the left edge of the examination area, and the left sensor camera 2 is inside the distance M2 from the right edge of the examination area. Similarly, since the thin light beam 6 is detected at the position, the fact that the overlapping range of the actual inspection area is M1 + M2 = M can be readily and easily found without performing particularly complicated calculations. .

  Of course, even when the inspection surface 3a of the wide article 3 passes through another unspecified position, at each time point, similarly, from the left end of the inspection area of the right sensor camera 1, The total distance between the distance to the position of the thin light beam 6 detected by the sensor camera 1 and the distance from the right end of the inspection area of the left sensor camera 2 to the position of the thin light beam 6 detected by the sensor camera 2 is ( In effect, the number of pixels corresponding to the total distance) is the overlapping range of the actual inspection area, so in any case, even if the inspection surface of the wide article is displaced from moment to moment, there is no delay. The overlapping range can be quickly interrupted, and for example, the overlapping information is averaged, that is, the inspection information of the overlapping range (distance N “or M” in the illustrated example) is temporarily added and then divided into two. Process to calculate the average value of inspection information, For example, superiority or inferiority selection processing of overlapping information, that is, individual inspection information in the corresponding overlapping range is individually compared, and the one with the higher inspection signal level (or exceptionally the lower one) is selected and adopted with priority. Processing, for example, one-side priority adoption processing of duplication information, that is, in any sensor camera, inspection information inside the position of a thin light beam (in the example shown, distance L1-N1 " Or, the inspection information of L1-M1 ”and the inspection information of distance L2-N2“ or L2-M2 ”in the sensor camera 2) are preliminarily adopted, and the position of the thin light beam is selected. Processing for always cutting off outside inspection information (in the illustrated example, inspection information of the distance N1 “or M1” in the sensor camera 1 and inspection information of the distance N2 “or M2” in the sensor camera 2) ( Or a predetermined place The sensor camera's inspection information is preferentially used, and all the redundant information of the remaining sensor cameras is cut off)), etc. Inspection information is organized, and wide articles can be efficiently and accurately inspected based on the organized inspection information.

  In the above-described embodiment, the number of sensor cameras is set to a minimum of two for convenience of explaining the basic configuration. However, it is necessary to improve the inspection accuracy, for example. Accordingly, it is possible to increase the number of sensor cameras to three or more, and it is sufficient to irradiate a thin light beam to the central portion in the inspection area corresponding to the number of inspection areas that are overlapped.

  Further, as exemplified in the above-described embodiment, if a mode in which a thin light beam is irradiated almost in the middle of the overlapped inspection area is adopted, the processing of the overlapping inspection information has an advantage that it is easy to average, but the thin light beam The irradiation position is not limited to the middle of the overlapped inspection area, and even if the inspection surface of the wide article is displaced, the central portion of the overlapped inspection area does not deviate from the overlapped inspection area. (A part excluding the vicinity of both ends of the overlapped examination area) is sufficient.

  Although not shown in the figure, when an area sensor camera is used as a sensor camera in order to inspect each area of a predetermined area in the process of intermittently transporting a discontinuous non-band wide article, Naturally, it is necessary to irradiate a thin light beam extending in a line extending so as to satisfy the area length in the same direction as the conveyance direction of the wide article. Even if a line sensor camera is used, if an aspect in which a thin light beam extending in the same direction as the conveyance direction of the wide article is irradiated is used, the inspection area of each sensor camera is defined as the conveyance direction of the wide article. In the orthogonal direction, it is not necessary to arrange them in a straight line, which is convenient because the assembly of the inspection apparatus becomes relatively simple. For this reason, even if the inspection areas of the line sensor camera are not exactly aligned and are slightly misaligned in the conveyance direction of the wide article, they will overlap if it is known in advance that there is a misalignment. Since it is possible to correct misalignment when information processing of inspection information is performed, there is no practical problem.

  However, if the inspection area of the line sensor camera is arranged in a substantially straight line in the direction orthogonal to the conveying direction of the wide article, a thin light beam is irradiated in a spot shape to the center of the overlapped inspection area. Even if it exists, the irradiation aspect of a thin light beam is not restricted to the linear form extended in the same direction as the conveyance direction of a wide article. Further, from the viewpoint of clarity of the position to be detected, it is preferable that the position is as thin as possible under the condition that detection by the sensor camera is possible. And as such a light beam, a laser beam is suitable because of the straightness of light, and the bright red color of a commercially available red laser projector is relatively versatile, but it is not limited. In short, a light beam having a color different from the color originally present in the wide article is sufficient.

  In addition, as a sensor camera, although a color sensor camera is suitable from the viewpoint of color discrimination, a wide article to be inspected is used, for example, in the case of inspecting the presence of wrinkles in a colored film having a single color or a small number of colors. In the case of a non-multicolor system, even if a monochrome sensor camera is used, a thin light beam having a color different from the color originally present in the wide article is used as a line (or point) having a black and white density different from that of the wide article itself. Since it can be detected, there is no practical problem.

  In addition, it is sufficient to provide a desired number of illumination members for illuminating the inspection surface of a wide article, if necessary, for example, when holes or cracks are present as defects in the wide article to be inspected, or For example, when the wide article to be inspected is translucent, an illuminating member may be provided on the back side of the inspection surface of the wide article, or may be provided alone if necessary. In particular, when using a color sensor camera as a sensor camera and inspecting holes and cracks existing in wide articles as defects, it is a color different from the color of the thin light beam that irradiates the inspection surface. If an illumination member that irradiates a color different from the color originally present in the wide article is provided on the back side of the inspection surface of the wide article or is provided alone, the detection information of the illumination on the back side is included. Since it becomes easy to test | inspect a hole and a crack as a fault based on this, it is very effective.

  It should be noted that holes and cracks exist as defects in the wide article to be inspected, and when the defect passes through the position of the thin light beam, detection of the thin light beam by the sensor camera is temporarily disabled. However, in such a case, assuming that the basic irradiation position of the thin light beam is constant (non-moving), for example, it is considered that the thin light beam is detected at a predetermined position. (Assuming) the estimated overlap of the actual inspection area is estimated or detected, for example, on the front side or the back side of the defect (upper side or lower side in the conveyance direction of the wide article) There is no problem if the detection position of the thin light beam in the defective portion is estimated based on the detection information of the thin light beam and the overlapping range of the actual inspection area is estimated.

  Moreover, there is no special restriction | limiting about the conveyance mechanism / conveyance apparatus of a wide article, A conventionally well-known various conveyance mechanism / conveyance apparatus may be employ | adopted as needed. Although not shown in the figure, when inspecting the presence or absence of cracks in the direction intersecting the conveying direction, for example, when inspecting a crack in a veneer veneer, illumination is performed on the back side of the inspection surface of the wide article. The height of the transport mechanism before and after the inspection area of the line sensor camera is slightly different from that provided (from the smoothness of transport, preferably the upper side in the transport direction is higher and the transport direction is If the lower side is made lower), cracks inherent in wide articles are slightly enlarged near the inspection area of the line sensor camera, making it easier to detect the illumination on the back side. It is. Furthermore, there are no particular restrictions on what kind of inspection is performed on a wide article based on the organized inspection information, and various conventionally known inspections can be performed as necessary.

  As apparent from the above, according to the inspection method for a wide article according to the present invention, not only when the inspection surface of the wide article always passes a certain position (height), but also the inspection surface of the wide article passes through a different position. Even when there is a case, it is possible to accurately perform the inspection as desired, especially when the wide article has batters and undulations, and the position of the inspection surface of the wide article changes from moment to moment. However, since the desired inspection can be performed promptly and accurately without any particular trouble, it is extremely convenient for the inspection of wide articles having such properties.

It is a schematic perspective explanatory drawing of the inspection apparatus used for implementation of the inspection method of the wide article which concerns on this invention. It is a schematic back explanatory drawing of the inspection apparatus used for implementation of the inspection method of the wide article which concerns on this invention. It is a schematic side view explanatory drawing of the inspection apparatus used for implementing the inspection method of the wide article which concerns on this invention. It is a general | schematic perspective explanatory drawing of the inspection apparatus used for implementation of the inspection method of a certain wide article conventionally. It is a schematic back surface explanatory drawing of the inspection apparatus used for implementation of the inspection method of a certain wide article conventionally. It is a schematic side view explanatory drawing of the inspection apparatus used for implementation of the inspection method of a wide article from before.

Explanation of symbols

1.2: Sensor camera 3: Wide article 3a: Inspection surface 4 of wide article: Illumination member 5: Projector 6: Thin light beam 7: Information processing mechanism

Claims (5)

  When inspecting a wide article using a plurality of sensor cameras, the inspection area between adjacent sensor cameras is set to overlap the desired width on the inspection surface of the wide article, and the overlapped inspection area A thin light beam of a color different from the color originally present on the wide article is irradiated to the center of the inside, and based on the information of the thin light beam detected by each sensor camera, an actual inspection on the inspection surface of the wide article A method for inspecting a wide article, wherein an overlapping range of areas is calculated, and inspection is performed by appropriately processing overlapping inspection information.   2. The inspection method for a wide article according to claim 1, wherein the inspection surface of the wide article is irradiated with a thin light beam in a line extending in the same direction as the conveying direction of the wide article.   2. The inspection method for a wide article according to claim 1, wherein the inspection surface of the wide article is irradiated with a thin light beam in a spot shape.   4. The method for inspecting a wide article according to claim 1, wherein the thin light beam to be irradiated is a laser beam.   5. The method for inspecting a wide article according to claim 1, 2 or 3, or 4 using a color sensor camera.

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