Imaging unit and inspection system

Abstract

The present invention provides a technology having a configuration that enables further improvement in judgment accuracy. An imaging unit in an inspection system that performs visual inspection of an object to be inspected includes an imaging section, an illumination section arranged around the imaging section, and a protection section that covers the imaging section and the illumination section, the protection section including a plate-like member configured by connecting a first flat section and a second flat section via a bent portion that is bent in a dogleg shape, and the imaging section is located on the back side of the first flat section.

Description

[Technical Field]

[0001] The present invention relates to an imaging unit in a visual inspection system for an object to be inspected, and to an inspection system. [Background technology]

[0002] There is an inspection system that captures an image of the appearance of an inspection object while the object is being dropped, and determines and selects non-conforming inspection objects from the captured image (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4915129 Summary of the Invention [Problem to be solved by the invention]

[0004] In an inspection system, the imaging conditions affect the accuracy of the determination.

[0005] Therefore, an object of the present invention is to provide an imaging unit having a configuration that enables further improvement in the accuracy of determination, and an inspection system that uses the imaging unit. [Means for solving the problem]

[0006] The present invention provides an imaging unit in an inspection system for performing visual inspection of an inspection object, An imaging unit; an illumination unit disposed around the imaging unit; a protection section that covers the imaging section and the illumination section; Equipped with the protection portion includes a plate-like member configured by connecting a first planar portion and a second planar portion via a bent portion bent in a dogleg shape, The imaging unit is located on the rear side of the first planar unit.

[0007] The present invention also provides an inspection system for performing a visual inspection of an inspection object, comprising: the first imaging unit; the second imaging unit described above; a processing device that controls the operations of the first imaging unit and the second imaging unit and determines an inspection object to be selected from among the inspection objects based on images captured by the first imaging unit and the second imaging unit; Equipped with The first imaging unit and the second imaging unit are arranged so that the first planar portion of the first imaging unit and the first planar portion of the second imaging unit are respectively positioned on the upper side, and so that they face each other toward the area through which the object to be inspected passes. [Effects of the Invention]

[0008] It is possible to provide an imaging unit having a configuration that enables further improvement in determination accuracy, and an inspection system that uses the imaging unit. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing an example of the appearance of an inspection system 10. [Figure 2A] FIG. 1 is a block diagram showing an example of the functional configuration of an inspection system 10. [Figure 2B] FIG. 2 is a diagram showing an example of the hardware configuration of an information processing device 206. [Figure 3A] FIG. 2 is a diagram showing an example of the external configuration of an imaging unit 101. [Figure 3B] FIG. 4 is a diagram showing another example of the external configuration of the imaging unit 101. [Figure 4A] FIG. 4 is a diagram showing another example of the external configuration of the imaging unit 101. [Figure 4B] FIG. 2 is a diagram showing an example of a cross-sectional structure of the imaging unit 101. [Figure 5] FIG. 2 is a diagram for explaining an example of the arrangement of imaging units 101A and 101B in an inspection system. [Figure 6] FIG. 10 is a diagram for explaining an example of control timing of imaging and lighting in the inspection system. [Figure 7] 3A and 3B are diagrams illustrating an example of the structure of a windshield 301. [Figure 8] FIG. 3 is a diagram showing an example of the configuration of a hood 312. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.

[0011] First, the external configuration of an inspection system 10 that performs visual inspection of an inspection object will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the external configuration of the inspection system 10 corresponding to an embodiment. In Fig. 1, the inspection system 10 can be configured to include imaging units 101A and 101B, a belt conveyor 102, a discharge unit 103, etc. In this embodiment, the inspection object includes grains such as rice and wheat, other grains, seeds, processed raw materials, and other granular objects, as well as industrial products such as tablets, screws, nuts, buttons, and rubber products, and even foods such as vegetables, meat, fried foods, and frozen foods.

[0012] In this embodiment, under the control of an external information processing device (information processing device 206 in FIG. 2A), the imaging units 101A and 101B capture images of the appearance of the inspection object while the inspection object is being transported on the belt conveyor 102 and falling between them. The captured images are provided to the information processing device 206, and if an inspection object determined to be non-conforming because its shape or color does not meet a certain standard is found, the ejection unit 103 is operated to eject the air and sort out the inspection object determined to be non-conforming.

[0013] 2A is a block diagram showing an example of the functional configuration of an inspection system 10 according to an embodiment. As shown in FIG. 2A, in the inspection system 10, an information processing device 206 controls the operations of an imaging unit 201, an illumination unit 202, a discharge unit 203, a transport unit 204, and an object supply unit 205.

[0014] The imaging unit 201 is configured to include a two-dimensional area sensor, an AD converter, etc., and can use imaging elements such as CCD and CMOS. By using a two-dimensional area sensor, the angle of view is wider than that of the line sensors that have been widely used in conventional sorting devices, and by capturing images of the inspection object multiple times, the inspectable area can be substantially increased.

[0015] The number of pixels of the area sensor can be, for example, several million pixels, but is not limited to this. The number of pixels depends on the size of the object to be inspected and the criteria used for the inspection. For example, if the size of the external features of the object to be inspected, which are used to determine whether the criteria are met, is above a certain level, it is sufficient to ensure image quality such as VGA. On the other hand, if it is necessary to determine fine features, a high-resolution image sensor such as 4K can be used. The imaging unit 201 may include a hood arranged on the light-receiving surface of the image sensor to prevent external light from entering the image sensor.

[0016] The imaging unit 201 can capture images at a frame rate of 20 to 35 frames per second under the control of the information processing device 206. The frame rates shown here are merely examples, and higher frame rates are also possible. In this embodiment, an example will be described in which images are captured at 30 frames per second.

[0017] Next, the illumination unit 202 is arranged around the imaging unit 201 so as to surround the imaging unit 201, and includes a plurality of LEDs arranged in a matrix. The illumination unit 202 may be arranged above, below, left, and right of the imaging unit 201. It may also be arranged only above and below, or only left and right. Alternatively, it may be arranged only on one side of the top and bottom where light directionality is better, or on one side of the left and right where light directionality is better. The illumination unit 202 irradiates light onto the inspection object when the imaging unit 201 captures an image.

[0018] The imaging units 101A and 101B are configured to include a camera unit that combines an imaging section 201 and an illumination section 202, and a plurality of such camera units may be arranged in each of the imaging units 101A and 101B.

[0019] The discharge section 203 is a mechanism for discharging air corresponding to the discharge unit 103, and is configured as, for example, a blower mechanism that releases compressed air using an electromagnetic valve, a flap drive mechanism, or an electric fan including a fan and a motor. By operating the discharge section 203, air can be sent into the space into which the inspection object falls. The operation of the discharge section 203 is controlled by the information processing device 206, and when the inspection object is determined to be non-conforming based on the image captured by the imaging section 201, the discharge section 203 is activated to sort the inspection object.

[0020] The conveying unit 204 corresponds to the belt conveyor 102, and conveys the inspection objects and supplies them to the inspection space where the imaging units 101A and 101B perform imaging. It may also include a mechanism for conveying inspected objects. The object supplying unit 205 is a mechanism that ejects the inspection objects from the holder in which they are held and supplies them to the conveying unit 204. The operations of the conveying unit 204 and the object supplying unit 205 are controlled by the information processing device 206. Note that the operations of the conveying unit 204 and the object supplying unit 205 may be controlled by a control device other than the information processing device 206. In that case, the information processing device 206 can cooperate with the control device.

[0021] The information processing device 206 is a device that controls the operations of the imaging unit 201, the lighting unit 202, the discharge unit 203, the transport unit 204, and the object supply unit 205, and is configured by, for example, a personal computer. The information processing device 206 processes the image acquired from the imaging unit 201 to determine whether the inspection object being imaged satisfies certain standards, and if it is determined that the standards are not met, it controls the discharge unit 203 to operate a fan to blow out air and sort out the non-conforming inspection object.

[0022] Next, an example of the hardware configuration of the information processing device 206 will be described with reference to Fig. 2B. In Fig. 2B, a processor 261 executes various application programs for controlling the operations of the OS, imaging unit 201, lighting unit 202, discharge unit 203, transport unit 204, and object supply unit 205 stored in a hard disk (HD) 263, and controls temporary storage of information, files, and the like required for executing the programs in a RAM 262. The processor 261 includes a CPU, a GPU, an FPGA, an ASIC, and the like. The RAM 262 functions as the main memory, work area, and the like of the processor 261. The HD 263 stores application programs, driver programs, an OS, control programs, processing programs for executing processing corresponding to this embodiment, and the like.

[0023] The display 264 is a display means for displaying commands input from the operation unit 269, information acquired from the outside, etc. The interface (hereinafter referred to as I / F) 265 is a communication interface for connecting to external devices such as the imaging unit 101 or a network. The ROM 266 stores programs such as basic I / O programs. The external storage drive 267 can load programs stored in a medium 268 into this computer system. The medium 268 as a recording medium stores predetermined programs and related data. The operation unit 269 is a user interface that allows the operator of this device to input instructions, and is composed of a keyboard and a mouse. The system bus 270 controls the flow of data within the device.

[0024] Next, the external configuration of the imaging units 101A and 101B (hereinafter also simply referred to as imaging unit 101) will be described with reference to Figures 3A and 3B. Figure 3A is a diagram showing an example of the external configuration when viewed from the front side of the windshield 301 of the imaging unit 101.

[0025] In FIG. 3A , a windshield (cover) 301 is attached to the imaging unit 101 to prevent dust and other particles from entering the camera lens. The windshield 301 is attached to a frame 302 and is bent in a dogleg shape at a bend indicated by reference numeral 301a. The windshield 301 and frame 302 together form a protective unit that covers the imaging unit 101 and protects it from dust. The windshield 301 is made of colorless, transparent acrylic and is configured so as not to block light incident on the imaging unit 201 or light emitted from the illumination unit 202. Note that the windshield 301 may be made of glass or resin such as polycarbonate, in addition to acrylic. On the other hand, the frame 302 is made of, for example, metal or plastic and has a light-blocking structure. Camera units 310 and 320, each combining the imaging unit 201 and the illumination unit 202, are arranged behind the windshield 301.

[0026] The camera units 310 and 320 basically have a common structure, and in the following description, the components designated by reference numerals 31X and 32X are common components. Therefore, descriptions made with reference to 31X also apply to 32X. Furthermore, the same number of camera units 310 and 320 are arranged in each of the imaging units 101A and 101B, and when describing the imaging units separately, a capital letter A or B is added to the end of the name. Components designated by the letter A are components of imaging unit 101A, and components designated by the letter B are components of imaging unit 101B. The only difference between the letters is which imaging unit they belong to; the basic configuration is the same as long as they are designated by 31X and 32X.

[0027] FIG. 3B shows an example of the configuration of camera units 310 and 320, with the windshield 301 removed from the state shown in FIG. 3A. Camera unit 310 includes LED illumination units 311, 313, 314, and 315. Each LED illumination unit surrounds an area where an image sensor (not shown) is located, and a hood 312 is disposed over the image sensor. Note that the top, bottom, left, and right arrangement of the LED illumination units is merely an example, and any combination of these arrangements may be used. Hood 312 is cut at an angle to allow contact with windshield 301. The material of hood 312 can be, for example, silicone, resin, metal, rubber, wood, or glass. By attaching hood 312 so that it is sufficiently close to windshield 301, reflections such as flare can be reduced. A lens for the internal image sensor may be disposed inside hood 312.

[0028] Similarly, camera unit 320 is also provided with LED illumination units 321, 323, 324, and 325, and is surrounded by hood 322. Hood 322 is also cut at an angle to allow contact with windshield 301. A lens for the internal imaging element may be disposed inside hood 322.

[0029] A plurality of camera units 310 can be arranged in the horizontal direction of FIG. 3B, and windshield 301 and frame 302 are configured to have a width that allows the number of camera units 310 to be arranged.

[0030] Next, the external configuration of the imaging unit 101 will be further described with reference to FIGS. 4A and 4B. FIG. 4A is a diagram showing an example of the external configuration of the imaging unit 101 as seen from the side. FIG. 4A also shows the configuration shown in FIGS. 3A and 3B. FIG. 4A also shows that heat sinks are attached to the back of the LED illumination units 311, 313, and 315. This is a cooling mechanism for reducing heat from each LED illumination unit. The cooling mechanism may be forced cooling using a fan or water cooling. Also provided is a control unit 400 connected to the LED illumination unit 311 and an imaging element (not shown). The control unit 400 includes mechanisms 400A, 400B, and 400C for controlling the LEDs and a mechanism 400B for controlling the imaging element (not shown), and is connected to the information processing device 206 via a cable 401.

[0031] Fig. 4B is a diagram showing an example of the cross-sectional structure at the position indicated by line AA in Fig. 3A. In addition to the above-mentioned configuration, Fig. 4B shows the cross-sectional structure of windshield 301. Also shown is imaging element 316 inside hood 312.

[0032] Next, the positional relationship between the imaging units 101A and 101B will be described with reference to Fig. 5. In the inspection system 10, the imaging units 101A and 101B are arranged in the same direction with the imaging elements 316 positioned above the bent portion 301a of the windshield 301, and facing each other toward the area through which the inspection object passes.

[0033] In FIG. 5, the shaded area 501 indicates the angle of view of the image sensor 316B of the imaging unit 101B. Arrows 502 and 503 indicate the normal direction to the installation surface of the LED illumination units 321A and 325A of the imaging unit 101A and indicate exemplary illumination directions. Arrow 504 indicates the direction in which the object to be inspected passes. While some light from the LED illumination units 321A and 325A is diffused, the linear component of the light travels parallel to the LED illumination units 321A and 325A, or perpendicular to or intersecting with the surface of the windshield 301, which is positioned along the illumination units 321A and 325A. Therefore, the light from the LED illumination units 321A and 325A travels through the windshield 301. The light emitted from the LED illumination units 321A and 325A deviates from the angle of view of the image sensor 316B indicated by area 501, as indicated by arrows 502 and 503.

[0034] Meanwhile, light from LED illumination units 321A and 325A that strikes the object under inspection and is reflected is received by image capture element 326A and visualized as an image. Therefore, the installation direction of LED illumination units 321A and 325A, in other words, the light irradiation direction, is desirably determined so that the most light reflected from the object under inspection is supplied to image capture element 326A. Furthermore, the intersection of arrows 502 and 503 is set so that they intersect within the position or range through which the object under inspection passes, allowing the most light to be irradiated onto the object under inspection. This maximizes the amount of information about the object under inspection, thereby maintaining the quality of the captured image.

[0035] The positional relationship between the imaging units 101A and 101B can be determined depending on, for example, the size of the object to be inspected, the illumination angle of the LED illumination unit, mechanical interference, and the like.

[0036] Furthermore, there is a risk that the light emitted from the LED illumination unit 321A or the like may enter the imaging element 326B of the opposing imaging unit 101B. For this reason, the imaging units 101A and 101B can expose the imaging elements 326 at different times rather than at the same time.

[0037] Fig. 6 is a diagram showing the relationship between the timing of each exposure in the imaging unit 101 and the timing of light emission by the LED illumination unit. In Fig. 6, the upper side shows the imaging unit 101A and the control timing of the LED illumination unit (311A, 313A, 314A, 315A, 321A, 323A, 324A, 325A) of the imaging unit 101A. The imaging unit 101A captures images at a frame rate of 30 frames per second. Pulse 601 indicates the time during which the imaging unit 101A is exposed to light. The interval between pulses 601 is approximately 33 milliseconds.

[0038] The LED illumination unit of the imaging unit 101 operates to emit light from the LED while exposure is being performed by the imaging unit 101A. However, if the LED is lit at the same rate of 30 frames per second as the imaging unit 101A, there is a risk that the human eye will perceive blinking. Therefore, the number of times the LED is lit per unit time can be made greater than the number of images taken per unit time. For example, if the number of images taken per unit time is set to 30, the number of times the LED is lit per unit time can be set to 60 or 90. This makes it impossible for the human eye to perceive blinking. Figure 6 shows the case where the number of times the LED is lit is set to 90.

[0039] 6, the control timing of the imaging unit 101B and the LED illumination units (311B, 313B, 314B, 315B, 321B, 323B, 324B, 325B) of the imaging unit 101B is shown at the bottom. The imaging unit 101B also captures images at a frame rate of 30 frames per second. However, the position of pulse 603 indicating the exposure timing of the imaging unit 101B is shifted in time from the position of pulse 601, and is also shifted in time from pulse 602 of the LED illumination unit for the imaging unit 101.

[0040] As a result, during the period when imaging unit 101B is capturing images, the LED illumination unit of imaging unit 101A is turned off, and therefore the quality of the captured image by imaging unit 101B is not reduced by light from the LED illumination unit of imaging unit 101A. Similarly, during the period when imaging unit 101A is capturing images, the LED illumination unit of imaging unit 101B is turned off, and therefore the quality of the captured image by imaging unit 101A is not reduced by light from the LED illumination unit of imaging unit 101B.

[0041] 7, the relationship between windshield 301 and the light-receiving plane of image sensor 316 will be described. FIG. 7 is a diagram showing an exemplary cross-sectional structure for explaining the installation angle of windshield 301 with respect to the light-receiving plane of image sensor 316.

[0042] As shown in FIG. 7, the windshield 301 in this embodiment is configured as a plate-like member bent into a dogleg shape. More specifically, a first flat surface 301b, on the back side of which an image sensor 316, a hood 312, and an LED illumination unit 311 are arranged, and a second flat surface 301c, on the back side of which an LED illumination unit 315 is arranged, are connected via a bent portion 301a. The LED illumination unit 311 is arranged on the back side of the first flat surface 301b and along the first flat surface 301b, and the LED illumination unit 315 is arranged on the back side of the second flat surface 301c and along the second flat surface 301c. Although not shown in FIG. 7, the LED illumination units 313 and 314 are arranged on the back side of the first flat surface 301b.

[0043] 7, the imaging surface of imaging element 316 is represented by dotted line 701. Dotted line 702 indicates a plane parallel to the imaging surface represented by dotted line 701 and is set to be tangent to bend 301a of windshield 301. In this case, if the angle of first flat surface portion 301b relative to dotted line 702 is θ1 and the angle of second flat surface portion 301c relative to dotted line 702 is θ2, then θ2≧θ1 holds. Regarding the magnitudes of θ1 and θ2, for example, the lower limit of θ1 can be set to approximately 26 degrees and the lower limit of θ2 can be set to approximately 16 degrees. However, these numerical values ​​are merely examples, and the values ​​of θ1 and θ2 can be selected as angles larger than the angle θmin at which the reflected image from the opposing imaging unit 101 does not fall within the angle of view after calculating reflections by the windshield 301, etc., based on at least one of the angle of view of the imaging section 201 of the imaging unit 101, the distance to the object to be inspected expected at the time of imaging, the installation angle, arrangement, and irradiation angle of the lighting section 202, the angle with the opposing imaging unit, etc.

[0044] The angle with the opposing imaging unit can be found, for example, as the intersection angle of the normal to the imaging plane of each imaging unit 101. In Fig. 5, the imaging elements 326A and 316B of the opposing imaging units 101A and 101B face each other directly, so the intersection angle is 0 degrees, but an intersection angle may also be set. Furthermore, when imaging units 101A and 101B are further added with 101C to capture images from three directions, an intersection angle is set, and the values ​​of θ1 and θ2 can be set according to the intersection angle.

[0045] FIG. 8 shows an example of the external configuration of the hood 312. The hood 312 can be made of, for example, a silicone material and is attached to the rear surface of the windshield 301. The hood 312 has a shape in which a cylindrical first portion 312a on the lower side is connected to a reverse-tapered second portion 312b on the upper side. The reason for providing the second portion 312b halfway along the first portion 312a is to avoid interference with the angle of view of the image sensor 316. More specifically, if the hood 312 were reverse-tapered from the base, the diameter of the base would be too small, causing interference with the lens and reducing assembly efficiency. This is to avoid these issues. If the height of the hood 312 can be made shorter, the first portion 312a may be omitted.

[0046] Additionally, second portion 312b on the upper side of hood 312 has an opening cut to match the inclination of windshield 301. The inclination angle of the opening surface corresponds to θ1 shown in Fig. 7 with respect to the horizontal plane. By setting an appropriate angle for hood 312 to match windshield 301 and fitting it in close contact with windshield 301 in this way, ghosts and flares caused by noise other than specular reflection can be prevented.

[0047] According to the above-described embodiment, in an imaging unit in an inspection system for visually inspecting an object to be inspected, by using a two-dimensional area sensor in the imaging section, it is possible to widen the angle of view and increase the inspectable area by capturing images multiple times. Furthermore, when capturing images multiple times, the positional relationship between the object to be inspected (the object) and the lighting changes depending on the timing of the images, so images with different shadows and highlights can be acquired. This means that the same object can be inspected multiple times with different representations, reducing the risk of overlooking an object.

[0048] Furthermore, by arranging a bent-in-the-Leg windshield on the imaging unit, it is possible to prevent a flat surface from being formed in front of the imaging unit. This windshield configuration can almost completely eliminate specular reflection, so it is possible to prevent the illumination during imaging from being reflected by the windshield of the opposite imaging unit and appearing in the image, which would significantly reduce the imaging quality.

[0049] Furthermore, by attaching the hood close enough to the windshield, it is possible to reduce reflections such as flare caused by noise other than specular reflection. Also, since the hood can be placed in close contact with the windshield, the noise reduction effect can be ensured more reliably.

[0050] <Summary of the embodiment> The above-described embodiment discloses at least the following imaging unit and inspection system. (1) An imaging unit in an inspection system for performing a visual inspection of an object to be inspected, An imaging unit; an illumination unit disposed around the imaging unit; a protection section that covers the imaging section and the illumination section; Equipped with the protection portion includes a plate-like member configured by connecting a first planar portion and a second planar portion via a bent portion bent in a dogleg shape, The imaging section is an imaging unit located on the back side of the first planar section. (2) The first planar portion has a first angle of inclination with respect to an imaging surface of an imaging element of the imaging unit, the second planar portion is inclined at a second angle with respect to the imaging surface of the imaging element; The imaging unit according to (1), wherein the second angle is equal to or greater than the first angle. (3) The lighting unit is The imaging unit according to (2), further comprising a first illumination unit located on the rear side of the first planar portion and arranged along the first planar portion. (4) The lighting unit is The imaging unit according to (2) or (3), further comprising a second illumination unit located on the rear side of the second planar portion and arranged along the second planar portion. (5) The lighting unit is The imaging unit according to any one of (2) to (4), further comprising a third illumination unit located on the rear side of the first planar unit and arranged parallel to the imaging surface of the imaging element. (6) The imaging unit further includes a hood for the imaging element, The imaging unit described in any one of (2) to (5), wherein the hood contacts the back surface of the first planar portion and has an opening cut at an inclination corresponding to the inclination of the first planar portion. (7) The hood is configured by connecting a cylindrical first portion and an inversely tapered second portion, The imaging unit according to (6), wherein the second portion is in contact with the rear surface of the first planar portion. (8) The imaging unit according to any one of (2) to (7), wherein the imaging section includes a two-dimensional area sensor. (9) A plurality of imaging units and a plurality of lighting units are provided, The imaging unit according to any one of (2) to (8), wherein the protection section covers the plurality of imaging sections and the plurality of lighting sections. (10) An inspection system for performing a visual inspection of an object to be inspected, A first imaging unit according to any one of (2) to (9), A second imaging unit according to any one of (2) to (9), a processing device that controls the operations of the first imaging unit and the second imaging unit and determines an inspection object to be selected from among the inspection objects based on images captured by the first imaging unit and the second imaging unit; Equipped with An inspection system wherein the first imaging unit and the second imaging unit are arranged so that the first planar portion of the first imaging unit and the first planar portion of the second imaging unit are respectively positioned on the upper side, and so that they face each other toward an area through which the object to be inspected passes. (11) Regarding the first imaging unit and the second imaging unit, The inspection system described in (10), wherein the first angle and the second angle are calculated based on at least one of the angle of view of the imaging unit, the distance to the object to be inspected estimated at the time of imaging, the installation angle, arrangement and illumination angle of the lighting unit, and the angle with the opposing imaging unit, and are set to an angle larger than the minimum angle at which the reflected image by the plate-like member of one imaging unit does not fall within the angle of view of the other imaging unit. (12) The inspection system described in (10) or (11), wherein the processing device controls the first imaging unit and the second imaging unit so that imaging by the first imaging unit and the second imaging unit is performed alternately in time. (13) The processing device controls each of the illumination units so that illumination by the illumination unit of the first imaging unit and illumination by the illumination unit of the second imaging unit are performed alternately in time in accordance with the imaging timing of the first imaging unit and the second imaging unit. (14) The inspection system according to any one of (10) to (13), wherein the processing device causes the illumination unit to emit light a number of times per unit time that is greater than the number of times the first imaging unit and the second imaging unit capture images per unit time.

[0051] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention.

Claims

1. An imaging unit in an inspection system for performing visual inspection of an inspection object, An imaging unit; An illumination unit disposed around the imaging unit; a protection section for covering the imaging section and the illumination section; Equipped with the protection portion includes a plate-like member including a first planar portion and a second planar portion connected via a bent portion bent in a dogleg shape, The imaging unit is disposed on the rear side of the first planar portion.

2. the first planar portion has a first angle of inclination with respect to an imaging surface of an imaging element of the imaging unit; the second planar portion has a second angle with respect to the imaging surface of the imaging element; The imaging unit of claim 1 , wherein the second angle is greater than or equal to the first angle.

3. The illumination unit includes: a first illumination unit located on the rear side of the first planar portion and arranged along the first planar portion; The imaging unit according to claim 2 , further comprising:

4. The illumination unit includes: a second illumination unit located on the rear side of the second planar portion and arranged along the second planar portion; The imaging unit according to claim 2 , further comprising:

5. The illumination unit includes: The imaging unit according to claim 2 , further comprising a third illumination section located on a rear side of the first planar section and disposed parallel to the imaging surface of the imaging element.

6. The imaging unit further includes a hood for the imaging element, The imaging unit according to claim 2 , wherein the hood is in contact with a rear surface of the first planar portion and has an opening cut at an inclination corresponding to an inclination of the first planar portion.

7. The hood is configured by connecting a cylindrical first portion and a reverse tapered second portion, The imaging unit according to claim 6 , wherein the second portion is in contact with the rear surface of the first planar portion.

8. The imaging unit according to claim 2 , wherein the imaging section includes a two-dimensional area sensor.

9. The imaging device includes a plurality of imaging units and a plurality of illumination units, The imaging unit according to claim 2 , wherein the protection section covers the plurality of imaging sections and the plurality of illumination sections.

10. An inspection system for performing a visual inspection of an inspection object, comprising: A first imaging unit according to any one of claims 2 to 4; A second imaging unit according to any one of claims 2 to 4; a processing device that controls operations of the first imaging unit and the second imaging unit and determines an inspection object to be selected from among the inspection objects based on images captured by the first imaging unit and the second imaging unit; Equipped with An inspection system, wherein the first imaging unit and the second imaging unit are arranged so that the first planar portion of the first imaging unit and the first planar portion of the second imaging unit are each positioned on the upper side, and so that they face each other toward an area through which the object to be inspected passes.

11. Regarding the first imaging unit and the second imaging unit, The inspection system described in claim 10, wherein the first angle and the second angle are calculated based on at least one of the angle of view of the imaging unit, the distance to the object to be inspected expected at the time of imaging, the installation angle, arrangement and irradiation angle of the lighting unit, and the angle with the opposing imaging unit, and are set to an angle larger than the minimum angle at which a reflected image by the plate-like member of one imaging unit does not fall within the angle of view of the other imaging unit.

12. The inspection system according to claim 10 , wherein the processing device controls the first imaging unit and the second imaging unit so that imaging by the first imaging unit and the second imaging unit is performed alternately in time.

13. The inspection system according to claim 12, wherein the processing device controls each of the illumination units so that illumination by the illumination unit of the first imaging unit and illumination by the illumination unit of the second imaging unit are performed alternately in time corresponding to imaging timing in the first imaging unit and the second imaging unit.

14. The inspection system according to claim 10 , wherein the processing device causes the illumination unit to emit light a number of times per unit time greater than a number of times the first imaging unit and the second imaging unit capture images per unit time.

Images