Method for inspecting wooden products and image acquisition device for inspecting wooden products

Abstract

To develop inspection means capable of inspecting a long material with a small width such as a lamina.SOLUTION: In an image acquisition device for inspecting a wood product in a device for inspecting the wood product with the use of a surface image, a terminal end of a carry-in conveyor and a leading end of a carry-out conveyor are obliquely arranged in a plane view and an imaging area is obliquely arranged in a plane view. Imaging means includes irradiation devices and imaging devices. The illumination devices and the imaging devices are arranged along a direction of the imaging area.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the technical field of manufacturing wood products. [Background technology]

[0002] In recent years, the number of cedar, cypress, and other trees planted in Japan's forests has grown, resulting in an abundant stock of timber in the country. Coupled with the movement toward a decarbonized society, there are high hopes for the use of timber as a building material. When used as building materials, etc., it is required to inspect the quality and manufacture and supply products that meet the appropriate standards. Wood is used in two forms: solid wood and laminated wood such as plywood and laminated lumber. Plywood is produced by cutting veneers from raw logs, drying them, gluing the veneers together, and pressing them. The present applicant has proposed a method and a sorting device for evaluating and sorting veneers for plywood by using transmitted and reflected light, as shown in Patent Document 1 (Japanese Patent No. 6017390) and Patent Document 2 (Japanese Patent Laid-Open No. 2020-144727). Since irradiated light cannot penetrate plywood, which is made up of laminated veneers, inspection methods using transmitted light cannot be used.Therefore, we have proposed a wood product inspection device in Patent Document 3 (Patent Application No. 2021-134887) that includes a surface inspection device that uses vertical and oblique irradiation light irradiated onto the surface of the wood product, and an end grain inspection device that uses end grain irradiation light irradiated onto the end grain of the wood product.

[0003] The inventions proposed in Patent Documents 1 to 3 involve providing a gap between a leading conveyor and a trailing conveyor in the conveying direction, irradiating the surface between them with light and capturing an image to obtain a surface image for evaluation. These inventions target plywood and veneers for plywood, and inspection is possible because the width is wide enough to span the gap. Recently, materials such as laminated timber and CLT have been attracting attention as structural materials for high-rise buildings. To ensure reliable structural design, it is necessary to evaluate the quality of the lamina, which is the material. With the previously proposed inspection device, it was difficult to obtain images for evaluation when using narrow lamina because the position was unstable in the inspection gap. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6017390 [Patent Document 2] Japanese Patent Publication No. 2020-144727 [Patent Document 3] Patent application No. 2021-134887 Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION An object of the present invention is to develop an inspection means capable of inspecting narrow, elongated materials such as lamina. [Means for solving the problem]

[0006] The present invention makes it possible to obtain evaluation images of long wooden materials such as lamina by transporting the long wooden materials in a stable position in the imaging area. To achieve a stable position, the long wooden materials are transported in an oblique position, or the imaging area is set obliquely so that the long wooden materials are gradually transferred from the carry-in conveyor to the carry-out conveyor, thereby ensuring a stable position. The gist of the present invention is as follows. 1. Using surface images Long length 1. A method for inspecting a wood product, comprising: An imaging area is provided between the carry-in conveyor and the carry-out conveyor, and the imaging means is disposed along the imaging area; Long length An image acquisition device for acquiring a surface image of a wooden product, The imaging means includes an illumination device and an imaging device, (A) Imaging area in the conveying direction In plan view If installed at an angle, Long length Wooden products in the direction of transport In plan view Transported in an orthogonal position, Imaging While passing through the area Long lengthAcquiring an image of the wooden product using an imaging means; or, (B) Imaging area in the conveying direction In plan view When installed in perpendicular directions, Long length Wooden products in the direction of transport In plan view Transporting in a diagonal position, Imaging While passing through the area Long length Acquiring an image of the wooden product using an imaging means; Characterized by Long length How to inspect wood products. 2. Using surface images Long length In an apparatus for inspecting wooden products, An image pickup means is placed between the carry-in conveyor and the carry-out conveyor. Long length An image acquisition device for a wooden product, The end of the carry-in conveyor and the beginning of the carry-out conveyor are arranged diagonally in a plan view, and the imaging area is arranged diagonally in a plan view, The imaging means includes an illumination device and an imaging device, and the illumination device and the imaging device are arranged along the direction of the imaging area. Long length Image acquisition device for inspecting wood products. 3. The imaging means are arranged above and below. The lighting device according to claim 2 has two types of lighting with different illumination angles. Long length Image acquisition device for inspecting wood products. 4. The image acquisition device according to claim 3, wherein the carry-in conveyor and the carry-out conveyor are configured as the same conveyor belt. 5. The method according to any one of 2. to 4., characterized in that the carry-in conveyors and the carry-out conveyors are arranged in parallel in at least three rows, and the imaging area formed between the carry-in conveyors and the carry-out conveyors is an oblique linear interval or an interval bent in a "L" shape. Long length Image acquisition device for inspecting wood products. 6. Using Surface Images Long length In an apparatus for inspecting wooden products, An image pickup means is placed between the carry-in conveyor and the carry-out conveyor. Long length An image acquisition device for a wooden product, The end of the carry-in conveyor and the beginning of the carry-out conveyor are arranged perpendicular to the conveying direction in a plan view. Long length A mechanism is provided to regulate the conveying position of wooden products from a right angle to an angle relative to the conveying direction, and the discharge conveyor Long length A mechanism is provided to regulate the conveying position of the wooden product from an angle to a perpendicular direction to the conveying direction. Between the loading and unloading conveyors, in plan view In the conveying direction The imaging areas are arranged at right angles, The imaging means includes an illumination device and an imaging device, and the illumination device and the imaging device are arranged along the direction of the imaging area. Long length Image acquisition device for inspecting wood products. The image acquisition device having this configuration can be equipped with the devices and mechanisms described in 3. to 5. 7. Long length The wooden product according to 2.3. or 6. is any one of lamina (material for laminated lumber, LVL, CLT), long sawn lumber (columns, beams, solid boards), laminated lumber, plywood, and CLT. Long length Image acquisition device for inspecting wood products. Any of the items listed in 8.2. to 4.6. Long length The image acquisition device for inspecting wooden products is provided with a means for analyzing and evaluating the image obtained from the image acquisition device. Long length Inspection equipment for wooden products. 9. The images obtained from the image acquisition device are analyzed and evaluated by the inspection device. And before and after this image acquisition device, Long length The facility is equipped with conveying and picking devices for supplying wood products, and also with devices for sorting, transporting, storing, and printing grades based on the results of the inspection. [Effects of the Invention]

[0007] 1. The present invention is a method for manufacturing long wooden products such as lamina. In plan viewBy carrying out diagonal conveyance or by setting the interval between the carry-in and carry-out conveyors at an angle, the wooden product straddles both the carry-in and carry-out conveyors in the imaging area, stabilizing its posture and enabling accurate images to be acquired quickly. In the present invention, an inspection method has been developed that captures images of the surface of narrow, long wooden products in an imaging area without a transport conveyor, and analyzes and evaluates the images. The present invention is capable of obtaining an evaluation image of a long wooden material such as a lamina by transporting the long wooden material such as a lamina in a stable position in the imaging area. In plan view Transport it at an angle or move the imaging area In plan view It is installed at an angle so that the long material gradually transfers from the carrying-in conveyor to the carrying-out conveyor, ensuring a stable posture. Although it is possible to transport a long wooden product along its length and take an image, it takes time to obtain an image of the entire product, which is inefficient. In plan view The tilted arrangement ensures sufficient spacing and stability of the conveying position. 2. The image capturing device described in claims 2 to 5 is formed between the end of the carry-in conveyor and the beginning of the carry-out conveyor, with the conveyor being tilted. In plan view This invention uses a diagonal interval as the imaging area. By devising a conveyor to form an oblique imaging area and arranging the imaging means along that area, we have created a device that can obtain stable images of long wooden products. 3. The transport conveyor is divided into an inlet and outlet conveyor, so an imaging outlet can be installed below, allowing images of the front and back surfaces of long wooden products to be acquired. By simultaneously evaluating the images of the front and back surfaces, knots that penetrate from the front to the back can be evaluated. Images of wood products can be acquired by capturing images of the reflected light from irradiated light, allowing the surface properties of the wood product to be evaluated. Various properties of the surface of the wood product can be evaluated by comparing images obtained using vertically reflected light and obliquely reflected light. Images are captured using a line sensor camera, stored in memory, and then combined to generate a single image of the wood product. Evaluation data can also be accumulated and used for inspection using AI. For example, knots, insect holes, cracks, rot, discoloration, etc. can be detected. By evaluating the front and back surfaces separately and then evaluating properties common to both surfaces, it is possible to determine whether the property penetrates through the thickness. 4. By forming the loading and unloading conveyors from the same conveyor belt, the speeds of the loading and unloading conveyors can be synchronized. The belt can be routed around the area where the imaging device is installed, ensuring space for the imaging device below. In addition, adjustment means such as speed adjustment, tension adjustment, and spacing adjustment can be shared. 5. The loading and unloading conveyors are made up of multiple rows of belt conveyors. Three or more rows are preferable for handover and transport, and four or more rows are usually used for long materials over 2m. A conveyor belt in the center provides stability for handover. On the other hand, for long, warped materials, if there is a central belt, the center will act as a fulcrum, making the long material unstable and risking the risk of not being able to obtain accurate images. To avoid this risk, measures such as not having a central belt or setting the level of the central belt slightly lower can be taken. Furthermore, since any slight warping of the lamina is corrected during the process of applying adhesive and crimping, even warped lamina are subject to quality evaluation. 6. The oblique imaging area can also be shaped like a dogleg. The ends of the infeed conveyors on both sides are long and the center is short, while the outfeed conveyor is long in the center and short on both sides, forming a dogleg-shaped space between them. The imaging means are also arranged on the left and right to form a dogleg shape. In this way, the long material leaves the conveyor at the center, but is stable because it is supported on both sides, and when both ends of the long material leave the conveyor, the center is supported by the outfeed conveyor, making it easy to stabilize. 7. The invention of claim 6 is that the end of the carry-in conveyor and the beginning of the carry-out conveyor are perpendicular to the conveying direction, and an imaging area is provided at a distance. The long material is regulated so that its posture is at an angle on the carry-in conveyor, and it flows, and in the imaging area In plan view The wooden products pass through at an angle, and then on the discharge conveyor, a reverse restriction is applied to correct the conveying position of the wooden products to a right angle to the conveying direction. In the imaging area, wooden products are transported across both conveyors, so their posture is stable and accurate images can be obtained. This device requires a mechanism to adjust the posture of the wooden products, and also requires a gap between the front and back of the wooden products. This transport attitude changing mechanism can also achieve the same effects as those in 2. to 6. above. 8. The wooden products that can be inspected by the present invention are long lumber, and mainly consist of long lumber such as lamina, pillars, beams, and solid boards, which are materials for laminated lumber, LVL, CLT, etc., but laminated products such as laminated lumber, plywood, and CLT can also be inspected. 9. Images obtained by the image acquisition device of the present invention can be analyzed to inspect wooden products. Various inspection devices proposed by the applicant can be used. Then, based on the inspection and evaluation, the products are sent to subsequent processes, such as sorting and stockpiling. Japanese coniferous trees such as cedar, pine, cypress, and larch, which were planted after the war, have grown and are increasing in volume as lumber, but due to low lumber prices and insufficient care such as pruning, there is discoloration due to knots and oil, and the quality varies greatly. By appropriately evaluating these trees using this invention, it is possible to promote the use of these trees. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. [Figure 2] FIG. 4 is a diagram showing the transport posture and the arrangement of the image acquisition means. [Figure 3] FIG. 1 is an explanatory diagram of a conveyor belt. [Figure 4] 1 shows a perspective view of a first embodiment. [Figure 5] 1 shows a plan view of a first embodiment. [Figure 6] 1A and 1B show a front view and a cross-sectional view of a first embodiment. [Figure 7] FIG. 10 is a diagram showing a "C"-shaped embodiment of the second embodiment. [Figure 8] FIG. 10 is a diagram showing an example of changing the oblique conveying posture according to the third embodiment; [Figure 9] FIG. 1 is a diagram showing an example of a wooden product to be inspected. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention is a wood product inspection device that can evaluate the surface properties of long wooden products such as lamina using images captured by irradiating light and capturing reflected light. The inspection method compares images obtained using light reflected from a vertical direction with images obtained using light reflected from an oblique direction to compare the state of shadows caused by unevenness and determine the presence of live knots, knotholes, discoloration, etc. The invention also proposes an image acquisition device for inspecting wooden products, which is adapted to acquire images of long wooden products. The image acquisition device is equipped with a device for continuously capturing images of wooden products while transporting them, with a transport device for carrying in and out in front of and behind the imaging area where images are captured using a line sensor type imaging means. Since it is necessary to stabilize the posture of narrow wooden products in the imaging area, the imaging area is positioned in the direction of transport. In plan view If installed at an angle, the wooden product In plan view Even if the wooden product is transported at a right angle (short side direction), it is supported by the front and rear transport devices, so the posture of the wooden product is stable. In plan view If installed at a right angle, the wooden product In plan view The object is transported at an angle and is supported by the transport devices in front and behind it across the imaging area to ensure stability.

[0010] Figure 9 shows an example of a lamina to be inspected by the present invention. Laminae are long, narrow sawn boards approximately 15–60 mm thick, 100–300 mm wide, and 2000–6000 mm long, and are the basic material for laminated lumber (CLT). Evaluating lamina performance is an important factor affecting the quality of laminated lumber products. For example, the strength performance of CLT is classified according to its bending performance, and the strength grade of usable lamina is determined according to the strength grade of the CLT. Laminae whose constituent layers have different strength grades and are symmetrical about the central axis in the thickness direction of the CLT are called "different-grade configurations." Laminae whose constituent layers have the same strength grade are called "same-grade configurations." Furthermore, lamina with a specified upper limit for the bending Young's modulus are designated as "Type B configurations." When applying the inspection devices proposed in Patent Documents 1 and 2 to long, narrow lamina, there is a risk of them getting stuck between the loading and unloading conveyors and falling, which can result in inaccurate images being obtained.

[0011] The image acquisition device of the present invention will be outlined with reference to FIGS. 1 to 3 and FIG. 6(b). Figure 1 shows an outline of an image acquisition device for inspecting wood products 5, which acquires images of the surfaces of wood products as they are transported. The transport device 1 is made up of an infeed conveyor 11 and an unfeed conveyor 12. An imaging area 13 is provided between the infeed conveyor 11 and the unfeed conveyor 12, and an imaging means 6 equipped with a surface illumination means 62 and a surface imaging device 61 is located above the imaging area 13. The imaging area 13 is provided at an angle to the transport direction in a plan view. In order to provide the imaging area 13 at an angle, the ends of the infeed conveyor 11 and the unfeed conveyor 12 are formed so that they are oblique in the width direction. This configuration allows the wooden product 5 to In plan viewEven when transported in the short direction, the section supported by one conveyor is shorter, and the wooden product 5 is supported by both the carry-in and carry-out conveyors, allowing it to maintain a stable posture. If the width of the imaging area is set to be approximately the same as the width of the wooden product, when the center of the wooden product is in the imaging area, the leading and trailing ends of the wooden product in the longitudinal direction are supported by the carry-in conveyor and the carry-out conveyor, so the wooden product is passed on in a stable posture. If the wooden product's posture is stable, the reflected light from the lighting does not waver, allowing the surface characteristics to be accurately imaged. The image of the wood product 5 obtained by the surface imaging device 61 is analyzed and evaluated for properties by the inspection device 10.

[0012] The conveying posture of the wooden product and the arrangement of the imaging means are shown in Figure 2. This is an example of a conveying device using four belt conveyors. In Figure 2(a), the four conveyors that make up the loading conveyor 11 are set so that the end of the upper conveyor in the figure is to the right of the lower conveyor, and the leading edges of the four conveyors of the unloading conveyor 12 are set to the left from top to bottom so that they are parallel to the end of the loading conveyor. This conveyor arrangement allows the imaging area 13 to In plan view The imaging area is formed obliquely, and the imaging means 6 can be arranged along the imaging area. The wooden product 51 is placed on the conveyor 11 in the longitudinal direction. In plan view Even if the wooden product 51 is transported at a right angle, it will be taken over by the carry-out conveyor 12 earlier on the lower side of the imaging area 13 shown in the figure, and will be taken over by the carry-out conveyor 12 later on the upper side of the figure. When the wooden product 51 leaves the carry-in conveyor 11 at the lower part of the figure, most of it is still supported on the carry-in conveyor 11 side, so its posture is stable, and it will gradually move towards the carry-out conveyor 12 side, so the posture of the wooden product 51 can be stabilized throughout the entire imaging area 13.

[0013] In Figure 2(b), of the four conveyors that make up the loading conveyor 11, the two central conveyors shown in the figure are set so that their ends are short, and of the four conveyors that make up the unloading conveyor 12, the two central conveyors are set so that their ends are long. This conveyor arrangement allows the imaging area 13 to In plan view It is formed in an "U" shape, and the imaging means 6 can also be arranged in an "U" shape along the imaging area. Even if the wooden product 51 is transported with its longitudinal direction perpendicular to the carry-in conveyor 11, it will be taken over by the carry-out conveyor 12 earlier in the illustrated center of the imaging area 13 and later at the top and bottom as shown. When the wooden product 51 leaves the carry-in conveyor 11 in the illustrated center, its posture is stable because the top and bottom are still supported by the carry-in conveyor 11 side, and it will gradually move towards the carry-out conveyor 12 side, so the posture of the wooden product 51 can be stabilized throughout the entire imaging area 13.

[0014] FIG. 2(c) shows the leading and trailing ends of the four conveyors that make up the carry-in conveyor 11 and the carry-out conveyor 12 in the conveying direction. In contrast They are lined up at right angles. This conveyor arrangement allows the imaging area 13 to be In plan view The imaging means 6 is also formed at a right angle along the imaging area. In plan view are placed at right angles. By transporting the wooden products 51 in an oblique position, they are quickly transferred to the carry-out conveyor 12 on the upper side of the imaging area 13 as shown in the figure, and are slowly transferred to the carry-out conveyor 12 on the lower side as shown in the figure. Since the wooden products 51 are transferred sequentially from the carry-out conveyor 11 to the carry-in conveyor 12, the position of the wooden products 51 can be stabilized throughout the entire imaging area 13. In addition, a position changing mechanism is provided to change the position of the wooden products during transport to a position perpendicular to the transport direction or an oblique position, so that the wooden products can be matched to the stacking device that takes them out or loads them.

[0015] Imaging area 13 In plan view The diagonal conveyor 1 can be configured using belts, chains, rollers, etc. Belts are the preferred conveyor. A roller conveyor can also be used, but there is a risk that the wooden products will bounce off the rollers. An example of the structure of the transport device is shown in FIG. In this example, the carry-in conveyor 11 and the carry-out conveyor 12 are formed by a single common conveyor. By forming them from a common belt, the conveying speed and tension of the carry-in conveyor 11 and the carry-out conveyor 12 are synchronized. Also, in this example, an imaging area 13 is provided, which is formed at the interval between the carry-in conveyor 11 and the carry-out conveyor 12.

[0016] The conveying device 1 shown in Fig. 3 is composed of four rows of conveying belts. Fig. 3(a) is a plan view, and Fig. 3(b) shows an example of a side view of the carry-in conveyor and the carry-out conveyor. There are four rows of conveyors, namely, carry-in conveyors 11-1 to 11-4 and carry-out conveyors 12-1 to 12-4, and the four rows of conveyors are arranged diagonally opposite each other. In plan view An imaging area 13 is formed obliquely. The carry-in conveyor 11 and the carry-out conveyor 12 are formed by a conveyor belt 1A as shown in the side view. The conveying surface of the transport conveyor 1A is formed by a carry-in conveyor leading pulley 11A, a carry-in conveyor terminal pulley 11B, a carry-out conveyor leading pulley 12A, and a carry-out conveyor terminal pulley 12B. The carry-in and carry-out conveying surfaces are formed at the same height. In this example, the diameter of the carry-in conveyor terminal pulley 11B is made small. By using a pulley with a small diameter, it is possible to ensure the inclination required for providing oblique lighting for the back side. The basic configuration is comprised of a drive pulley 14 and a tension pulley 16 arranged on the lower side. Six belt detouring pulleys 17···17 are provided to detour the conveyor belt 1A downward to form an imaging area 13 between the carry-in conveyor end pulley 11B and the carry-out conveyor start pulley 12A. The belt is routed in a U-shape by the belt detouring pulleys 17, and the resulting space allows for the installation of a lower imaging means. In this device, a mechanism is provided to change the position of the input conveyor end pulley 11B back and forth, allowing adjustment of the spacing of the imaging areas 13. In response to this position change, the tension of the conveyor belt 1A is maintained by the tension pulley 16. Since the transport device 1 is made up of four rows of conveyor belts, the angle of the imaging area 13 can also be adjusted by providing a mechanism that can adjust the positions of both the leading pulley 12A of the output conveyor and the trailing pulley 12B of the output conveyor forward and backward.

[0017] In the example of FIG. 3, the carry-in conveyor 11 and the carry-out conveyor 12 are formed by a single belt, but they can also be formed by separate belts and controlled to synchronize their speeds. Also, in Figure 3(a), four rows of transport conveyors are shown in parallel with equal spacing, but if the spacing in the center is wider than on both sides, the probability of stable transport of long materials with warping increases. This is because if warping occurs, transporting the material so that the center where the center of gravity is located is lower will stabilize the material. Since slight warping can be corrected, if it is included in the quality inspection, inspection efficiency will improve. This conveying device 1 is a conveying device for an image acquisition device for inspecting wooden products, and a conveying device that picks up and conveys lamina from a stock is provided in front of this conveying device 1. In addition, after this conveying device 1, a post-process is provided where lamina that have been evaluated by analyzing the images are sorted and stored.

[0018] FIG. 6(b) shows the basic configuration of the imaging means. An imaging area 13 is provided between the transfer conveyor 11 and the discharge conveyor 12, and the imaging means 6 is disposed in this imaging area 13. The imaging means 6 is composed of a front surface imaging device 61, a front surface lighting means 62, a back surface imaging device 71, and a back surface lighting means 72. The imaging devices and lighting means are provided on the front and back surfaces of the wooden product to obtain images of both the front and back surfaces. The lighting means 62 and 72 are composed of reflected light lighting 62A and 72A and oblique light lighting 62A and 72A. The imaging device uses a line sensor type imaging device. The front surface side is provided above, with a front surface imaging device 61 directly above, a reflected light illuminator 62A at a large angle above, and an oblique light illuminator 62B obliquely above. Reflected light illumination and oblique illumination utilize the reflection of light at different angles to obtain images, allowing for three-dimensional analysis of the state of unevenness. The back side is provided below in the same manner as the front side. In order to ensure the angle of oblique lighting on the back side, in the illustrated example, the terminal pulley of the transfer conveyor 11 is made small. Then, the back side oblique lighting 72B is provided on the side of the terminal pulley of the transfer conveyor 11.

[0019] An inspection device that processes and evaluates images obtained from an imaging device can employ mechanisms described in Patent Documents 1 to 3 previously proposed by the applicant. Images captured by shining light and capturing reflected light can be used to obtain images of wood products that can be used to evaluate the surface properties of the wood product, and various properties of the surface of the wood product can be evaluated by comparing images obtained using light reflected from a vertical direction and light reflected at an angle. Images are taken with a line sensor camera, stored in memory, and synthesized to generate a single image of the wood product, and evaluation data can be stored and used to utilize AI for inspection. The inspection device is equipped with a grade determination device that determines the grade of a wooden product using predetermined determination parameters based on a line image of the wooden product obtained by a color line sensor type camera. Synchronization processing for generating an image of the entire surface of the wooden product from the line image can be performed by a wooden product detection sensor and encoder installed on the conveying device. The graded wood products are separated and piled up. By inspecting the front and back surfaces, it is possible to detect, evaluate, and grade live knots, dead knots, holes, cracks, insect holes, rot, discoloration, blade marks, and poor putty. By evaluating the front and back surfaces separately and then evaluating the properties common to both surfaces, it is possible to determine whether the properties penetrate through the thickness direction. [Example]

[0020] The image acquisition device of Example 1 is shown in Figures 4 to 6. Figure 4 is a perspective view, Figure 5 is a plan view, and Figure 6 is a cross-sectional view (a) along the imaging region and a front view (b). To make the plan view of Figure 5 easier to understand, the carry-in conveyor 11 and the carry-out conveyor 12 are arranged diagonally with a gap that forms the imaging area 13. The two conveyors are arranged in four parallel rows, with the carry-in conveyors 11 being assigned branch numbers 11-1 to 11-4 and the carry-out conveyors 12 being assigned branch numbers 12-1 to 12-4. Detection sensors 32, 32 that detect wooden products 51 are arranged between the carry-in conveyors 11-1 and 11-2 and between the carry-in conveyors 11-3 and 11-4. Between the imaging regions 13, a surface imaging device 61 consisting of a left surface imaging device 61L and a right surface imaging device 61R, and a surface illumination means 62 consisting of a reflected light illumination 62A and an oblique light illumination 62B are arranged. These imaging devices and lighting means are also provided below the transport conveyor for the back side. The state in which they are arranged above and below is shown in Figure 6. In the front view of Figure 6(b), imaging means 6 consisting of an imaging device and lighting means is provided between the carry-in conveyor 11 and the carry-out conveyor 12. In this example, the conveyor belts for carrying in and carrying out are configured as a single common belt. For this reason, the belt is curved in a U shape to accommodate the lighting and imaging device below. In the front view of Figure 6(b), imaging means 6, consisting of an imaging device and lighting means, is installed between the U-shaped curved carrying in conveyor 11 and carrying out conveyor 12. Reflected light illumination 62A and oblique light illumination 62B are irradiated toward the conveying level of carrying in conveyor 11 and carrying out conveyor 12, which transport wooden products 51, and surface imaging devices 61L and 61R are installed, focused on this conveying level. Two surface imaging devices 61 are placed on the left and right to separately photograph the long wooden product 51. The number of imaging devices is not limited to two, and the number can be increased. The imaging device is installed directly above, and the reflected light is positioned at a distance so as not to hit the imaging device. The oblique light is positioned so that it shines obliquely onto the surface of the wooden product to highlight its unevenness. For the rear side of the wooden product 51, a reflected light illuminator 72A and an oblique light illuminator 72B are irradiated, and rear image pickup devices 71L and 71R focused on this conveyance level are arranged. An encoder 31 is attached to the pulley of the carrying-in conveyor 11, and the signal from the detection sensor 32 and the timing of image acquisition by the imaging device are controlled based on the encoder signal to generate image data for the front and back surfaces of a single wooden product. A cross-sectional view is shown in Figure 6(a).

[0021] A perspective view of the device configuration is shown in FIG. The image information captured by the left surface imaging device 61L and the right surface imaging device 61R, which form the surface imaging device 61, is processed by the AI ​​controller surface 33A to generate and evaluate a surface image of the wood product. The image information captured by the left backside imaging device 71L and the right backside imaging device 71R that form the backside imaging device 71 is processed by the AI ​​controller back side 33B to generate and evaluate a backside image of the wooden product.

[0022] The operation is explained as follows: Wooden products 51 placed on the carry-in conveyor 11 are transported and detected by the detection sensor 32 near the end of the carry-in conveyor 11, and a detection signal is sent to two AI controllers 33A and 33B to identify the wooden product to be inspected. As the wooden products are transported, they enter the imaging area 13. Once the wooden products enter the imaging area 13, they leave the short carry-in conveyor 11-4 one by one, are illuminated from above and below, and images of the front and back are taken by the imaging means and sent to the AI ​​controllers 33A and 33B. The wooden products 51 leave the carry-in conveyor in order of length, and are transferred to each of the oppositely disposed carry-out conveyors 12-4 to 12-1. In the illustrated example, the distance between the two conveyors and the inclination of the imaging area 13 are set so that the front end of the wooden product 51 will land on the carry-out conveyor 12-4 before the rear end of the wooden product 51 leaves the carry-in conveyor 11-3. Therefore, the front end of the wooden product 51 will land on one of the four rows of carry-out conveyors 12 before the rear end of the wooden product 51 leaves two of the four rows of carry-in conveyors 11, so that the wooden product can pass through the imaging area 13 in a stable posture. Therefore, it is possible to acquire an image without any distortion. The timing of transporting the wooden product 51 is managed by an encoder 31 installed on the carry-in conveyor 11, and the detection signal from the detection sensor 32 and image data from a line sensor are integrated by an AI controller to obtain images of the front and back of the wooden product. Quality evaluation is carried out based on these images. [Example]

[0023] FIG. 7 shows a second embodiment of an image acquisition device in which the imaging region 13 is formed in a "L" shape. In this embodiment, the two outer conveyors 11-1 and 11-4 that make up the four rows of conveyors 11 are short, and the inner conveyors 11-2 and 11-3 are long, and the opposing unloading conveyors 12 are configured so that the two outer conveyors are long and the two inner conveyors are short. A "U"-shaped imaging area 13 is formed between these conveyors, and the imaging means 6 is also bent in the middle and shaped like an "U". The upper and lower lighting means and imaging devices that make up the imaging means 6 are the same as those in Example 1 except for their shape. As in Example 1, the leading edge of the wooden product 51 transported by the input conveyor 11 is detected by the detection sensor 32, and a signal is sent to the AI ​​controller. Images are then captured by the front and back imaging devices 61 and 71, and sent to the AI ​​controller, and images of the front and back surfaces are generated according to the timing signal of the encoder 32.

[0024] In this embodiment, the wooden product 51 in the imaging area 13 falls off the outer carry-in conveyors 11-1 and 11-4, but remains stable because the center of the wooden product 51 continues to be supported by the two inner carry-in conveyors 11-2 and 11-3, and the spacing is adjusted so that while more than half the width of the wooden product 51 is on these two carry-in conveyors, it is supported by the outer carry-out conveyors 12-1 and 12-4 of the carry-out conveyor 12. Therefore, the posture of the wooden product 51 moving in the imaging area 13 is stable, and clear images can be acquired. In this example, the wooden product 51 in the imaging area is supported at the center or both sides, so that its posture is stable. [Example]

[0025] FIG. 8 shows a third embodiment of the image capturing device in which a wooden product is conveyed in a tilted position and the imaging area 13 is formed perpendicular to the conveying direction. In this embodiment, the carry-in conveyor and the carry-out conveyor are each divided into front and rear sections, with a position change mechanism provided between them. The carry-in conveyor and the carry-out conveyor are configured in four rows, as in the first and second embodiments. The carry-in conveyor 11 is divided into a front carry-in belt conveyor 111 and a rear carry-in belt conveyor 113, between which a carry-in low-friction conveyor 112 and position-changing lifting members 114L and 114R are arranged. A left position-changing lifting member 114L and a right position-changing lifting member 114R are provided at the front and rear and are raised and lowered so as to appear and disappear from the conveyance level. The carry-out conveyor 12 is divided into a front carry-out belt conveyor 121 and a rear carry-out belt conveyor 123, between which are arranged a carry-out low-friction conveyor 122 and posture return lifting members 124L and 124R. The left posture return lifting member 124L and the right posture return lifting member 124R are provided perpendicular to the conveying direction and are raised and lowered so as to appear and disappear relative to the conveying level. An imaging area 13 is provided perpendicularly between the rear carry-in belt conveyor 113 and the front carry-out belt conveyor 121. The imaging device and lighting means constituting the imaging means 6 installed in the imaging area 13 are provided perpendicularly to the conveying direction along the imaging area, as in the first embodiment.

[0026] The right side of the wooden product 51 comes into contact with the right attitude-changing lifting member 114R during conveyance, and the left side advances and comes into contact with the left attitude-changing lifting member 114L, and at the point when the wooden product 51 becomes inclined with respect to the direction of advancement, the left attitude-changing lifting member 114L and the right attitude-changing lifting member 114R are lowered, and the wooden product 51 is conveyed by a rear carry-in belt conveyor 113 and sent into an imaging area 13, and images of the front and back are acquired by an imaging means. The wooden products 51 continue at an angle, are sequentially transferred onto the front discharge belt conveyor 121, and proceed to the discharge low-friction conveyor 122, where the left side of the wooden products 51 abuts against the left posture return lifting member 124L, and then the right side abuts against the right posture return lifting member 124R, and the posture of the wooden products 51 returns to a position perpendicular to the conveying direction. At this point, the left posture return lifting member 124L and the right posture return lifting member 124R are lowered and sent to the rear discharge belt conveyor 123, where they are sent to the subsequent process. The movement of the components that change their position relative to the conveying surface or return to their original position can be controlled using contact sensors or optical sensors. For example, when a wooden product comes into contact with the left or right components in the extended position, the components are lowered. After that, when the optical sensor detects the passage of the wooden product, the components are raised to prepare for contact with the next wooden product. The low-friction carry-in conveyor 112 and the low-friction carry-out conveyor 122, which change the position of the wooden products 51, are formed by belt conveyors or chain conveyors with low friction, making it easy to change positions. Chain conveyors have point contact, so they tend to have low friction. [Explanation of symbols]

[0027] 1. Conveyor device 1A Conveyor belt 10 Inspection equipment 11 Intake conveyor 11A Intake conveyor end pulley 11B Intake conveyor end pulley 12. Discharge conveyor 12A Discharge conveyor end pulley 12B Discharge conveyor end pulley 13 Imaging area 14 Drive pulley 15 Imaging interval adjustment mechanism 16 Tension pulley 17 Detour pulley 20 Image acquisition device 3. Control System 31 Encoder 32 detection sensor 33A AI Controller Surface 33B AI Controller back 5, 51 Wooden products 6. Imaging Method 61 Surface imaging device 61L Surface imaging device left 61R Surface Imaging Device Right 62 Surface illumination means 62A Reflected Lighting 62B Oblique Lighting 71 Backside imaging device 71L Rear image pickup device left 71R rear imaging device right 72 Backside illumination means 72A Reflected light illumination 72B Oblique lighting 111 Front loading belt conveyor 112 Low-friction conveyor 113 Rear loading belt conveyor 121 Front discharge belt conveyor 122 Low-friction discharge conveyor 123 Rear discharge belt conveyor 114 Posture-changing lifting member 114L Position change lifting member left 114R Right-hand lifting member for changing position 124 Posture return lifting member 124L Posture return lifting member left 124R Right side of lifting member for returning posture

Claims

1. 1. A method for inspecting long wooden products using surface images, comprising: An image capturing device for capturing a surface image of a long wooden product, comprising: a carry-in conveyor; a carry-out conveyor; and an imaging area provided between the two conveyors, and imaging means disposed along the imaging area, The imaging means includes an illumination device and an imaging device, (A) When the imaging area is provided at an angle to the conveying direction in a plan view, the long wooden product is conveyed in a perpendicular orientation to the conveying direction in a plan view, and an image of the long wooden product is acquired by the imaging means while it passes through the imaging area. or, (B) When the imaging area is provided in a direction perpendicular to the conveying direction in a plan view, the long wooden product is conveyed in an oblique position in a plan view with respect to the conveying direction, and an image of the long wooden product is acquired by the imaging means while it passes through the imaging area. A method for inspecting long wooden products.

2. An apparatus for inspecting long wooden products using surface images, An image capturing device for a long wooden product, comprising an input conveyor, an output conveyor, and an imaging means disposed between the two conveyors, The end of the carry-in conveyor and the beginning of the carry-out conveyor are arranged diagonally in a plan view, and the imaging area is arranged diagonally in a plan view, An image acquisition device for inspecting long wooden products, characterized in that the imaging means comprises an illumination device and an imaging device, and the illumination device and the imaging device are arranged along the direction of the imaging area.

3. The imaging means are arranged above and below, 3. The image acquisition device for inspecting long wooden products according to claim 2, wherein the lighting device has two types of lighting with different illumination angles.

4. 4. The image acquisition device according to claim 3, wherein the carry-in conveyor and the carry-out conveyor are constituted by the same conveyor belt.

5. An image acquisition device for inspecting long wooden products as described in any one of claims 2 to 4, characterized in that the loading conveyors and unloading conveyors are arranged in parallel in at least three rows, and the imaging area formed between the loading conveyors and the unloading conveyors is a diagonal linear interval or a curved "L"-shaped interval.

6. An apparatus for inspecting long wooden products using surface images, An image capturing device for a long wooden product, comprising an input conveyor, an output conveyor, and an imaging means disposed between the two conveyors, The end of the loading conveyor and the beginning of the unloading conveyor are arranged perpendicular to the conveying direction in a plan view, the loading conveyor is provided with a mechanism for restricting the conveying position of the long wooden products from a perpendicular angle to the conveying direction to an oblique angle, and the unloading conveyor is provided with a mechanism for restricting the conveying position of the long wooden products from an oblique angle to a perpendicular angle to the conveying direction, The imaging area is located between the infeed conveyor and the discharge conveyor, perpendicular to the conveying direction in a plan view. An image acquisition device for inspecting long wooden products, characterized in that the imaging means comprises an illumination device and an imaging device, and the illumination device and the imaging device are arranged along the direction of the imaging area.

7. An image acquisition device for inspecting long wooden products as described in Claim 2, 3 or 6, characterized in that the long wooden products are either lamina, long lumber, laminated timber, plywood or CLT.

8. An inspection device for long wooden products, comprising means for analyzing and evaluating images obtained from the image acquisition device for inspecting long wooden products according to any one of claims 2 to 4 and 6.

Images