Inspection device and inspection method

Abstract

An imaging lens (33) facing a workpiece placement plane (12) (placement plane) on which a workpiece (W) (object to be inspected) is placed from a Z direction (facing direction) is provided. The imaging lens (33) images light (Lo, Lv1, Lp1) incident from the object side on which the workpiece mounting plane (12) is provided on a solid-state imaging element (41) (imaging element) of a camera (32) provided on the image side. A first inclined optical system (61) that guides light in a first inclined direction (V1), which is inclined with respect to the Z direction, to the imaging lens (33) is provided. Then, the light (Lo, Lp1) reflected from the workpiece mounting plane (12) in the Z direction is imaged on a solid-state imaging element (41) through an imaging lens (33). Furthermore, the light (Lv1) reflected from the workpiece mounting plane (12) in the first inclined direction (V1) is guided to an imaging lens (33) by a first inclined optical system (61), and is imaged on a solid-state imaging element (41) by the imaging lens (33).

Description

Technical Field

[0001] The present invention relates to a technique for inspecting an inspection object based on the result of irradiating the inspection object with illumination light for capturing a two-dimensional image and pattern light for capturing a three-dimensional image and capturing the inspection object. Background Art

[0002] Patent Document 1 discloses a device that rotates a line sensor relative to an inspection object and images the inspection object with the line sensor, thereby acquiring a two-dimensional image of the inspection object. Patent Document 2 also discloses a device that irradiates solder with light of different hues (red / green) from two light sources and images the solder, thereby acquiring a three-dimensional image of the solder.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Patent Publication No. 3600010

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2009-168453 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] Thus, when inspecting an object, it is necessary to obtain both a two-dimensional image and a three-dimensional image of the object. Therefore, it is desirable to be able to obtain both a two-dimensional image and a three-dimensional image using a single inspection device. Specifically, this can be achieved using an inspection device that includes both a mechanism for illuminating the object with illumination light and capturing the illumination light reflected from the object to obtain a two-dimensional image, and a mechanism for illuminating the object with patterned light for optical segmentation and capturing the patterned light reflected from the object to obtain a three-dimensional image.

[0009] However, when acquiring a two-dimensional image, illumination light is captured from multiple directions (fields of view) as needed. Furthermore, when acquiring a three-dimensional image, patterned light diffusely reflected from the object being inspected is captured. This necessitates the installation of multiple cameras corresponding to the multiple directions for capturing illumination light, or a separate camera for capturing patterned light. This leads to increased size and cost of inspection equipment.

[0010] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to enable imaging from multiple directions for obtaining a two-dimensional image and imaging for obtaining a three-dimensional image to be performed by a single camera.

[0011] Technical solutions to problems

[0012] The inspection device according to the present application includes a camera having a shooting element that shoots received light; a shooting lens that opposes a placement plane provided on an object side and on which an inspection object is placed from a prescribed direct opposition direction; a first oblique optical system that guides light from the placement plane toward a first oblique direction oblique with respect to the direct opposition direction to the shooting lens; an illumination system that generates illumination light that is irradiated toward the placement plane; and a first pattern irradiation section that irradiates linear pattern light for measuring the shape of the inspection object placed on the placement plane by light sectioning from a first sectioning direction oblique with respect to the direct opposition direction toward the placement plane, the shooting lens imaging light reflected from the placement plane toward the direct opposition direction on the shooting element and imaging light reflected from the placement plane toward the first oblique direction guided by the first oblique optical system on the shooting element.

[0013] The inspection method according to the present application is an inspection method of inspecting an inspection object based on an image shot by a camera having a shooting element that images light incident from an object side on the shooting element from a shooting lens that opposes a placement plane provided on an object side and on which an inspection object is placed from a prescribed direct opposition direction, the inspection method including: a step of generating illumination light that is irradiated toward the placement plane; a step of irradiating linear pattern light for measuring the shape of the inspection object placed on the placement plane by light sectioning from a first sectioning direction oblique with respect to the direct opposition direction toward the placement plane; a step of guiding light from the placement plane toward a first oblique direction oblique with respect to the direct opposition direction to the shooting lens by a first oblique optical system; a step of imaging light reflected from the placement plane toward the direct opposition direction on the shooting element by the shooting lens; and a step of imaging light reflected from the placement plane toward the first oblique direction guided by the first oblique optical system on the shooting element by the shooting lens.

[0014] In the present invention (inspection device and inspection method) constructed in this manner, a photographic lens is provided, facing the mounting plane on which the inspection object is placed, from a facing direction. This photographic lens forms an image of light incident from the object side of the mounting plane onto the imaging element of a camera positioned on the image side. Furthermore, a first oblique optical system is provided, which guides light traveling in a first oblique direction relative to the facing direction to the photographic lens. Light reflected from the mounting plane in the facing direction is formed into an image of the imaging element by the photographic lens. Furthermore, light reflected from the mounting plane in the first oblique direction is guided by the first oblique optical system to the photographic lens and formed into an image of the imaging element by the photographic lens. In other words, light reflected from the mounting plane in multiple directions (the facing direction and the first oblique direction) is formed into an image on the imaging element of the same camera. Therefore, it is possible to illuminate the inspection object placed on the mounting plane with illumination light, and to have the camera capture images of the illumination light reflected in the facing direction and the illumination light reflected in the first oblique direction. Furthermore, it is possible to illuminate the inspection object with patterned light, and have the camera capture images of the patterned light reflected in the facing direction. In this way, imaging from multiple directions (the straight-on direction and the first oblique direction) for obtaining a two-dimensional image and imaging for obtaining a three-dimensional image can be performed using one camera.

[0015] Alternatively, the inspection device may be configured such that the illumination system includes a coaxial illumination unit that generates coaxial light that passes through the capturing lens in a facing direction from the image side, opposite the object side, toward the object side. The first oblique optical system redirects a portion of the coaxial light to a first oblique direction, thereby generating illumination light directed from the first oblique direction toward the mounting plane. The capturing lens emits light from the coaxial light, which is different from the portion, in a facing direction, thereby generating illumination light directed from the facing direction toward the mounting plane. In this configuration, the first oblique optical system can illuminate the mounting plane from the first oblique direction, and the capturing lens can reflect the illumination light from the mounting plane in the first oblique direction and return to the first oblique optical system, forming an image on the imaging element. In other words, illumination from the first oblique direction and imaging of the illumination light from the first oblique direction are performed using a common optical path. Furthermore, the capturing lens can illuminate the mounting plane from the facing direction, and the capturing lens can reflect the illumination light from the mounting plane in the facing direction and return to the capturing lens, forming an image on the imaging element. That is, the irradiation of the illumination light from the facing direction and the imaging of the illumination light from the facing direction are performed through the common optical path. In this way, by realizing the commonality of the optical path, the inspection device can be made compact.

[0016] Further, the inspection device can be configured such that the object plane of the normal optical path coincides with the object plane of the first oblique optical path, the normal optical path being an optical path of light emitted from the placement plane toward the normal direction and reaching the imaging element via the imaging lens, and the first oblique optical path being an optical path of light emitted from the placement plane toward the first oblique direction and reaching the imaging element via the first oblique optical system and the imaging lens. In this configuration, for example, irradiation / pickup of illumination light and irradiation / pickup of pattern light with respect to an inspection object placed on the placement plane can be performed in parallel. Thus, two-dimensional images and three-dimensional images of the inspection object can be efficiently acquired.

[0017] Further, the inspection device can be configured to further include an optical path adjustment member disposed between the placement plane and the imaging lens in the normal optical path, the optical path adjustment member causing light traveling from the placement plane toward the normal direction to be emitted toward the imaging lens in the normal direction after being made to take a detour, thereby causing the object plane of the normal optical path to coincide with the object plane of the first oblique optical path. In this configuration, for example, irradiation / pickup of illumination light and irradiation / pickup of pattern light with respect to an inspection object placed on the placement plane can be performed in parallel. Thus, two-dimensional images and three-dimensional images of the inspection object can be efficiently acquired.

[0018] Further, the inspection device can be configured to further include an optical path adjustment member disposed between the imaging lens and the imaging element in the first oblique optical path, the optical path adjustment member causing light incident from the imaging lens to be emitted toward the imaging element after propagating inside the optical path adjustment member, thereby causing the object plane of the first oblique optical path to coincide with the object plane of the normal optical path. In this configuration, for example, irradiation / pickup of illumination light and irradiation / pickup of pattern light with respect to an inspection object placed on the placement plane can be performed in parallel. Thus, two-dimensional images and three-dimensional images of the inspection object can be efficiently acquired.

[0019] Further, the inspection device can be configured such that the first pattern irradiation section and the first oblique optical system are disposed in a manner such that a direction in which pattern light incident on the placement plane from the first cut-off direction is specularly reflected coincides with the first oblique direction. In this configuration, pattern light can be irradiated from the first cut-off direction with respect to an inspection object having a specular reflection characteristic, and the pattern light specularly reflected by the inspection object can be guided to the imaging lens by the first oblique optical system. Thus, a three-dimensional image of the inspection object having the specular reflection characteristic can be further acquired with one camera.

[0020] Further, the inspection device can also be configured to further include: a second oblique optical system that guides light from the placement plane toward a second oblique direction oblique with respect to the direct direction to the photographing lens; and a second pattern irradiation section that irradiates a linear pattern light for measuring a shape of the inspection object placed on the placement plane by the light sectioning method from a second sectioning direction oblique with respect to the direct direction to the placement plane, the first oblique optical system is disposed on one side with respect to an optical axis of the photographing lens, the first pattern irradiation section is disposed on the other side opposite to the one side, the second oblique optical system is disposed on the other side, and the second pattern irradiation section is disposed on the one side. In this configuration, the photographing from the plurality of directions (the direct direction, the first oblique direction, and the second oblique direction) for acquiring the two-dimensional image and the photographing of the pattern light irradiated from the plurality of directions (the first light sectioning direction and the second light sectioning direction) for acquiring the three-dimensional image can be performed by one camera.

[0021] Further, the inspection device can also be configured such that the object plane of the direct light path, the object plane of the first oblique light path, and the object plane of the second oblique light path are identical, the direct light path is a light path of light emitted from the placement plane toward the direct direction reaching the photographing element via the photographing lens, the first oblique light path is a light path of light emitted from the placement plane toward the first oblique direction reaching the photographing element via the first oblique optical system and the photographing lens, and the second oblique light path is a light path of light emitted from the placement plane toward the second oblique direction reaching the photographing element via the second oblique optical system and the photographing lens. In this configuration, for example, the irradiation / photographing of the illumination light and the irradiation / photographing of the pattern light with respect to the inspection object placed on the placement plane can be performed in parallel. Therefore, the two-dimensional image and the three-dimensional image of the inspection object can be efficiently acquired.

[0022] Further, the inspection device can also be configured such that the first pattern irradiation section and the first oblique optical system are disposed in a manner that a direction in which pattern light incident from the first sectioning direction is specularly reflected on the placement plane coincides with the first oblique direction, and the second pattern irradiation section and the second oblique optical system are disposed in a manner that a direction in which pattern light incident from the second sectioning direction is specularly reflected on the placement plane coincides with the second oblique direction. In this configuration, the pattern light can be irradiated to the inspection object having the specular reflection characteristic from the first / second sectioning direction, and the pattern light specularly reflected by the inspection object can be guided to the photographing lens by the first / second oblique optical system. Therefore, the three-dimensional image of the inspection object having the specular reflection characteristic can be further acquired by one camera.

[0023] Alternatively, the inspection device can be configured such that the angle between the first oblique direction and the mounting plane is different from the angle between the second cutting direction and the mounting plane, and the angle between the second oblique direction and the mounting plane is different from the angle between the first cutting direction and the mounting plane. With this configuration, the pattern light irradiating the mounting plane does not pass through the first / second oblique optical system, thereby reducing the amount of pattern light. This allows for efficient irradiation of the required amount of pattern light and the acquisition of a three-dimensional image of the inspection object.

[0024] Alternatively, the inspection device may further include a control unit that sets a direct field of view and an oblique field of view for the imaging element, such that the imaging lens focuses light emitted from the mounting plane in the direct field of view on the imaging element's direct field of view, and focuses light emitted from the mounting plane in the first oblique direction and guided by the first oblique optical system on the oblique field of view on the imaging element's oblique field of view. In this manner, a single imaging element of a single camera can perform both imaging from multiple directions (the direct field of view and the first oblique direction) for obtaining a two-dimensional image and imaging for obtaining a three-dimensional image.

[0025] Alternatively, the inspection apparatus may further include a scanning drive unit that moves an inspection head, including an imaging element, an imaging lens, a first oblique optical system, an illumination system, and a first pattern illumination unit, relative to a support plane in a scanning direction. The control unit causes the scanning drive unit to move the inspection head relative to the scanning direction and causes the imaging element to repeatedly capture images formed by illumination light imaged in the oblique field of view region, thereby acquiring multiple oblique field of view illumination images. The multiple oblique field of view illumination images are arranged to acquire a two-dimensional image of the inspection object placed on the support plane. This configuration reduces the width of the oblique field of view illumination images acquired at a time. Consequently, when capturing images from the first oblique direction, it is possible to capture a two-dimensional image of the inspection object while suppressing the difference in telecentricity between the near side and the far side in the oblique direction.

[0026] Alternatively, the inspection device may be configured to further include an illumination light transmission filter disposed between the imaging element and the imaging lens so as to at least partially overlap the oblique viewing area. The illumination light transmission filter permits transmission of light of the wavelength of the illumination light while restricting transmission of light of the wavelength of the pattern light. The control unit acquires, as the oblique viewing illumination image, an image formed by light imaged in the area of ​​the oblique viewing area that overlaps the illumination light transmission filter. In this configuration, the oblique viewing illumination image can be appropriately acquired while suppressing the influence of the pattern light using the illumination light transmission filter.

[0027] Alternatively, the inspection device may be configured to further include a pattern light transmission filter disposed between the imaging element and the imaging lens so as to partially overlap the oblique viewing area and be adjacent to the illumination light transmission filter. The pattern light transmission filter permits transmission of light of the wavelength of the pattern light while restricting transmission of light of the wavelength of the illumination light. The control unit causes the scanning drive unit to relatively move the inspection head in a scanning direction and causes the imaging element to repeatedly capture images composed of pattern light formed in the area of ​​the oblique viewing area that overlaps the pattern light transmission filter, thereby acquiring multiple oblique viewing pattern images. By arranging the multiple oblique viewing pattern images, a three-dimensional image of the inspection object placed on the support plane is acquired. This configuration reduces the width of the oblique viewing pattern image acquired at a time. As a result, when capturing images from the first oblique direction, a three-dimensional image of the inspection object can be captured while suppressing the difference in telecentricity between the near side and the far side in the oblique direction. Furthermore, the oblique viewing pattern image can be appropriately acquired while suppressing the influence of the illumination light by the pattern light transmission filter.

[0028] Alternatively, the inspection apparatus may further include a scanning drive unit that moves an inspection head, including an imaging element, an imaging lens, a first oblique optical system, an illumination system, and a first pattern irradiation unit, relative to a support plane in a scanning direction. The control unit causes the scanning drive unit to move the inspection head relative to the scanning direction and causes the imaging element to repeatedly capture an image composed of patterned light formed on the facing field of view area, thereby acquiring multiple facing field of view pattern images. By arranging the multiple facing field of view pattern images, a three-dimensional image of the inspection object placed on the support plane is acquired. With this configuration, the width of the facing field of view pattern images acquired at a time can be suppressed. Consequently, when capturing images from the first oblique direction, a three-dimensional image of the inspection object can be captured while suppressing the difference in telecentricity between the front and back sides in the oblique direction.

[0029] Alternatively, the inspection device may be configured to further include a pattern light transmission filter disposed between the imaging element and the imaging lens so as to at least partially overlap the directly facing field of view area. The pattern light transmission filter permits transmission of light having a wavelength of the pattern light while restricting transmission of light having a wavelength of the illumination light. The control unit acquires, as the directly facing field of view pattern image, an image formed by light imaged in the area of ​​the directly facing field of view that overlaps with the pattern light transmission filter. In this configuration, the directly facing field of view pattern image can be appropriately acquired while suppressing the influence of the illumination light by the pattern light transmission filter.

[0030] Alternatively, the inspection device may be configured to further include an illumination light transmission filter disposed between the imaging element and the imaging lens so as to partially overlap the directly facing field of view area and be adjacent to the pattern light transmission filter. The illumination light transmission filter permits transmission of light of the wavelength of the illumination light while restricting transmission of light of the wavelength of the pattern light. The control unit causes the scanning drive unit to relatively move the inspection head in a scanning direction and causes the imaging element to repeatedly capture images composed of illumination light formed in the area of ​​the directly facing field of view area that overlaps the illumination light transmission filter, thereby acquiring multiple directly facing field of view illumination images. These multiple directly facing field of view illumination images are arranged to acquire a two-dimensional image of the inspection object placed on the mounting surface. This configuration reduces the width of the directly facing field of view illumination image acquired at a time. As a result, during imaging, a two-dimensional image of the inspection object can be captured while suppressing the difference in telecentricity between the near side and the far side in an oblique direction. Furthermore, the illumination light transmission filter suppresses the influence of the pattern light and enables appropriate acquisition of the directly facing field of view illumination image.

[0031] Alternatively, the inspection device may further include: a scanning drive unit for moving an inspection head, which includes an imaging element, an imaging lens, a first tilting optical system, an illumination system, and a first pattern irradiation unit, relative to a mounting plane in a scanning direction; and a rotation drive unit for rotating the inspection head about a rotation axis parallel to the facing direction. With this configuration, the inspection head can be rotated appropriately in response to changes in the scanning direction.

[0032] Effects of the Invention

[0033] According to the present invention, it is possible to perform imaging from multiple directions for obtaining a two-dimensional image and imaging for obtaining a three-dimensional image using one camera. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1A It is a plan view schematically showing an example of the inspection device according to the present invention.

[0035] Figure 1B It is a side view schematically showing the structure related to the inspection head included in the inspection apparatus of FIG. 1 .

[0036] Figure 2 This is a block diagram showing the electrical configuration of the inspection device of FIG. 1 .

[0037] Figure 3 It is a side view schematically showing the structure of a first example of the inspection head.

[0038] Figure 4A It is a bottom view schematically showing the positional relationship between the solid-state imaging element and the optical filter.

[0039] Figure 4B It is a side view schematically showing the positional relationship between the solid-state imaging element and the optical filter.

[0040] Figure 5A A diagram schematically showing a line image captured by an inspection head.

[0041] Figure 5B This is a diagram schematically showing the relationship between the region of interest set for the solid-state imaging element and the optical filter.

[0042] Figure 6A This is a diagram schematically illustrating a first example of a method for acquiring a three-dimensional image.

[0043] Figure 6B This is a diagram schematically illustrating a first example of a method for acquiring a three-dimensional image.

[0044] Figure 6C This is a diagram schematically illustrating a first example of a method for acquiring a three-dimensional image.

[0045] Figure 7 This is a diagram schematically illustrating a second example of a method for acquiring a three-dimensional image.

[0046] Figure 8 It is a side view schematically showing the structure of a second example of the inspection head.

[0047] Figure 9A This is a side view schematically showing the structure of a third example of the inspection head.

[0048] Figure 9B It is schematically represented in Figure 9A Diagram of the optical path adjustment components used in the inspection head.

[0049] Figure 10 This is a side view schematically showing the structure of a fourth example of the inspection head.

[0050] Figure 11 This is a diagram schematically showing a modified example of the relationship between the region of interest set for the solid-state imaging element and the optical filter. DETAILED DESCRIPTION

[0051] Figure 1A is a plan view schematically showing an example of an inspection device according to the present invention. Figure 1B 1 is a side view schematically showing a structure related to an inspection head included in the inspection apparatus of FIG. 1 . Figure 2 1 is a block diagram showing the electrical structure of the inspection device of FIG1. Figure 1A 、 Figure 1BIn the following figures, the horizontal direction X, the horizontal direction Y orthogonal to the direction X, and the vertical direction Z are appropriately indicated. This inspection apparatus 1 measures the two-dimensional and three-dimensional shapes of a workpiece W to be inspected.

[0052] The inspection apparatus 1 includes a horizontally arranged inspection table 11 , and the upper surface of the inspection table 11 serves as a workpiece mounting plane 12 for mounting the workpiece W. The workpiece mounting plane 12 is a horizontal plane parallel to the X direction and the Y direction.

[0053] The inspection device 1 includes a head drive mechanism 2 disposed on the upper side of an inspection table 11. The head drive mechanism 2 includes a pair of Y-axis rails 21 disposed at intervals in the X direction. The pair of Y-axis rails 21 extend parallel to the Y direction, and a workpiece mounting plane 12 is provided between the pair of Y-axis rails 21. In addition, the head drive mechanism 2 includes an X-axis rail 22 extending in the X direction, and both ends of the X-axis rail 22 in the X direction are supported by the pair of Y-axis rails 21 so as to be movable in the Y direction. Furthermore, the head drive mechanism 2 includes a head holder 23, and the head holder 23 is supported by the X-axis rail 22 so as to be movable in the X direction.

[0054] In addition, the head drive mechanism 2 has a Y-axis motor 24 that drives the X-axis rail 22 in the Y direction relative to the Y-axis rail 21. That is, one of the pair of Y-axis rails 21 has a built-in ball screw, and the X-axis rail 22 is mounted on the nut of the ball screw. The Y-axis motor 24 is coupled to one end of the ball screw built into the Y-axis rail 21, and drives the X-axis rail 22 in the Y direction by rotating the ball screw. Moreover, the head drive mechanism 2 has an X-axis motor 25 that drives the head holder 23 in the X direction relative to the X-axis rail 22. That is, the X-axis guide rail 22 has a built-in ball screw, and the head holder 23 is mounted on the nut of the ball screw. The X-axis motor 25 is coupled to one end of the ball screw built into the X-axis rail 22, and drives the head holder 23 in the X direction by rotating the ball screw.

[0055] The head holder 23 includes a Z-axis rail 231 supported by the X-axis rail 22 and a lifting frame 232 supported by the Z-axis rail 231 so as to be movable in the Z direction. In addition, the head driving mechanism 2 includes a Z-axis motor 26 ( Figure 2 Specifically, the Z-axis rail 231 includes a ball screw, and a lifting frame 232 is attached to the nut of the ball screw. The Z-axis motor 26 is coupled to one end of the ball screw included in the Z-axis rail 231, and drives the lifting frame 232 in the Z direction by rotating the ball screw.

[0056] The inspection device 1 also includes an inspection head 3 held by a head holder 23. The inspection head 3 is held on a lifting frame 232 so as to be rotatable in a rotation direction R centered around a rotation axis Az parallel to the Z direction. Specifically, the lifting frame 232 includes a rotation mechanism 233 for rotating the inspection head 3 in the rotation direction R. An R-axis motor 27 is mounted on the lifting frame 232. The rotation mechanism 233 rotates the inspection head 3 in the rotation direction R using the torque output by the R-axis motor 27.

[0057] The specific structure for driving the inspection head 3 in the X, Y, and Z directions and the rotational direction R is not limited to the example shown here. For example, the Y-axis motor 24, the X-axis motor 25, the Z-axis motor 26, or the R-axis motor 27 may be formed of linear motors.

[0058] like Figure 2 As shown, the inspection apparatus 1 includes a controller 9 that controls the head drive mechanism 2 and the inspection head 3. The controller 9 includes a processing unit 91, a Y position detection signal receiving unit 94, an X position detection signal receiving unit 95, a Z position detection signal receiving unit 96, and an R position detection signal receiving unit 97. The processing unit 91 is a processor such as a CPU (Central Processing Unit) and coordinates control within the inspection apparatus 1.

[0059] The Y-axis position detection signal receiving unit 94 obtains the Y-axis position detection signal Sy, which indicates the position of the inspection head 3 in the Y direction, from the encoder of the Y-axis motor 24 and transmits it to the arithmetic processing unit 91. The arithmetic processing unit 91 transmits the Y-axis motion command Cy, which indicates the amount of drive of the inspection head 3 in the Y direction, to the Y-axis position detection signal receiving unit 94. The Y-axis position detection signal receiving unit 94 transmits the Y-axis motion command Cy to the Y-axis motor 24. The Y-axis motor 24 then drives the inspection head 3 in the Y direction by the amount indicated by the Y-axis motion command Cy. At this time, the arithmetic processing unit 91 performs feedback control on the Y-axis motion command Cy based on the Y-axis position detection signal Sy, thereby positioning the inspection head 3 at the target position in the Y direction.

[0060] The X-axis position detection signal receiving unit 95 obtains an X-axis position detection signal Sx indicating the position of the inspection head 3 in the X direction from the encoder of the X-axis motor 25 and transmits it to the arithmetic processing unit 91. The arithmetic processing unit 91 transmits an X-axis motion command Cx indicating the amount of drive of the inspection head 3 in the X direction to the X-axis position detection signal receiving unit 95. The X-axis position detection signal receiving unit 95 transmits the X-axis motion command Cx to the X-axis motor 25. The X-axis motor 25 then drives the inspection head 3 in the X direction by the amount indicated by the X-axis motion command Cx. At this point, the arithmetic processing unit 91 performs feedback control of the X-axis motion command Cx based on the X-axis position detection signal Sx, thereby positioning the inspection head 3 at the target position in the X direction.

[0061] The Z-axis position detection signal receiving unit 96 obtains a Z-axis position detection signal Sz indicating the position of the inspection head 3 in the Z direction from the encoder of the Z-axis motor 26 and transmits it to the arithmetic processing unit 91. The arithmetic processing unit 91 transmits a Z-axis motion command Cz indicating the amount of drive of the inspection head 3 in the Z direction to the Z-axis position detection signal receiving unit 96. The Z-axis position detection signal receiving unit 96 transmits the Z-axis motion command Cz to the Z-axis motor 26. The Z-axis motor 26 then drives the inspection head 3 in the Z direction by the amount indicated by the Z-axis motion command Cz. At this time, the arithmetic processing unit 91 performs feedback control on the Z-axis motion command Cz based on the Z-axis position detection signal Sz, thereby positioning the inspection head 3 at the target position in the Z direction.

[0062] The R-axis position detection signal receiving unit 97 obtains the R-axis position detection signal Sr indicating the position of the inspection head 3 in the R direction from the encoder of the R-axis motor 27 and transmits it to the arithmetic processing unit 91. The arithmetic processing unit 91 transmits the R-axis motion command Cr indicating the amount of drive of the inspection head 3 in the R direction to the R-axis position detection signal receiving unit 97. The R-axis position detection signal receiving unit 97 transmits the R-axis motion command Cr to the R-axis motor 27. The R-axis motor 27 then drives the inspection head 3 in the R direction by the amount indicated by the R-axis motion command Cr. At this time, the arithmetic processing unit 91 performs feedback control on the R-axis motion command Cr based on the R-axis position detection signal Sr, thereby positioning the inspection head 3 at the target position in the R direction.

[0063] The arithmetic processing unit 91 transmits an imaging command Ci indicating execution of imaging to the inspection head 3 . Upon receiving the imaging command Ci, the inspection head 3 images the workpiece W and transmits image data Di of the workpiece W to the arithmetic processing unit 91 .

[0064] Figure 3 1 is a side view schematically showing the structure of a first example of an inspection head. Figure 3 , the scanning direction N of the inspection head 3 and the N1 and N2 sides of the scanning direction N are shown. Here, the scanning direction N is horizontal, and the N1 and N2 sides of the scanning direction N face opposite to each other. This scanning direction N is set relative to the inspection head 3. When the inspection head 3 rotates in the rotation direction R, the scanning direction N also rotates in the rotation direction R.

[0065] The inspection head 3 includes a cylindrical lens barrel 31 extending in the Z direction, a camera 32 mounted on the upper end of the lens barrel 31, and a photographing lens 33 mounted on the lower end of the lens barrel 31. Furthermore, the inspection head 3 includes an illumination system 34 for irradiating light for measuring two-dimensional shapes, and a pattern illumination system 35 for irradiating linear patterned light for measuring three-dimensional shapes using the light section method.

[0066] The photographing lens 33 is located on the upper side of the workpiece placement plane 12, and is opposed to the workpiece placement plane 12 in the Z direction. The optical axis Ao of the photographing lens 33 extends in parallel to the Z direction. That is, the optical axis Ao of the photographing lens 33 is perpendicular to the workpiece placement plane 12, and the photographing lens 33 is opposed in the direction in which the normal line of the workpiece placement plane 12 extends (Z direction). The photographing lens 33 emits light incident from the object side toward the camera 32 disposed on the image side, and the camera 32 photographs the light emitted from the photographing lens 33. The photographing lens 33 is a telecentric lens on both the object side and the image side, and forms an image of the object plane PI or P2 on the image plane.

[0067] The camera 32 includes a solid-state imaging element 41 and an optical filter 45. The solid-state imaging element 41 has a plurality of pixels arranged in two dimensions, and outputs data corresponding to the result of detecting light. As such a solid-state imaging element 41, a CMOS sensor can be given, for example. The solid-state imaging element 41 is disposed on the image plane of the photographing lens 33, and generates image data Di by receiving light imaged by the photographing lens 33. The optical filter 45 is disposed between the photographing lens 33 and the solid-state imaging element 41, and transmits light from the photographing lens 33 toward the solid-state imaging element 41. Figure 4A Figure 4B ). Figure 4A is a bottom view schematically showing the positional relationship between the solid-state imaging element and the optical filter, Figure 4B is a side view schematically showing the positional relationship between the solid-state imaging element and the optical filter. As Figure 4A shown, when viewed from the Z direction, the optical filter 45 is disposed so as to overlap the solid-state imaging element 41, and the solid-state imaging element 41 is contained inside the optical filter 45. Further, as Figure 4B shown, in the Z direction, the optical filter 45 is spaced apart from the solid-state imaging element 41.

[0068] ​The illumination system 34 includes a coaxial illumination unit 51 that generates coaxial light Lc that passes through the taking lens 33 in the Z direction, from the image side toward the object side of the taking lens 33. The coaxial illumination unit 511 includes a coaxial illumination unit 511 mounted on the side of the lens barrel 31 and a half mirror 513 disposed inside the lens barrel 31. The coaxial illumination unit 511 irradiates light toward the half mirror 513. The light irradiated by the coaxial illumination unit 511 is visible light. The half mirror 513 is disposed between the taking lens 33 and the camera 32. It reflects the light from the coaxial illumination unit 511 toward the taking lens 33 and transmits the light from the taking lens 33 toward the camera 32. The taking lens 33 emits the light reflected by the half mirror 513 as coaxial light Lc toward the object side of the taking lens 33. This coaxial light Lc is emitted from the taking lens 33 toward the object side parallel to the Z direction. That is, the coaxial light Lc emitted from the imaging lens 33 toward the object side is collimated light parallel to the Z direction.

[0069] The coaxial light Lc emitted from the central portion 330 of the photographing lens 33 travels parallel to the Z direction (i.e., straight) from the photographing lens 33 to the object plane P1 and irradiates the object plane P1 as illumination light Lo. Thus, the illumination light Lo is irradiated toward the object plane P1 from the Z direction.

[0070] Coaxial light Lc emitted from the peripheral portion 331 of the taking lens 33, which is closer to the N1 side than the central portion 330, enters the first oblique optical system 61. The first oblique optical system 61 is located on the N1 side of the optical axis Ao of the taking lens 33. It converts the coaxial light Lc emitted from the peripheral portion 331 into illumination light Lv1 that is incident on the object plane P2 along a first oblique direction V1 that is tilted relative to the Z direction. Furthermore, when viewed from above in the Z direction, the first oblique direction V1 is parallel to the scanning direction N, and the illumination light Lv1 is incident on the object plane P1 from the N1 side. The first oblique optical system 61 includes a reflective member 611 that reflects the coaxial light Lc emitted from the peripheral portion 331 of the taking lens 33 toward the N1 side of the scanning direction N; a reflective member 612 that reflects the light from the reflective member 611 diagonally downward; and a reflective member 613 that reflects the light from the reflective member 612 toward the object plane P2 in the first oblique direction V1. The reflecting components 611 , 612 , and 613 are, for example, mirrors or prisms.

[0071] Coaxial light Lc emitted from the peripheral portion 332 of the taking lens 33, which is closer to the N2 side than the central portion 330, enters the second oblique optical system 62. The second oblique optical system 62 is positioned on the N2 side of the optical axis Ao of the taking lens 33. It converts the coaxial light Lc emitted from the peripheral portion 332 into illumination light Lv2, which is incident on the object plane P2 along a second oblique direction V2 that is tilted relative to the Z direction. Furthermore, when viewed from above in the Z direction, the second oblique direction V2 is parallel to the scanning direction N, and the illumination light Lv2 is incident on the object plane P1 from the N2 side. The second oblique optical system 62 includes a reflective member 621 that reflects the coaxial light Lc emitted from the peripheral portion 332 of the taking lens 33 toward the N2 side of the scanning direction N; a reflective member 622 that reflects the light from the reflective member 621 obliquely downward; and a reflective member 623 that reflects the light from the reflective member 622 toward the object plane P2 in the second oblique direction V2. The reflecting components 621 , 622 , and 623 are, for example, mirrors or prisms.

[0072] Furthermore, the illumination system 34 includes a first oblique illumination unit 71 and a second oblique illumination unit 72. The first oblique illumination unit 71 is positioned above the object plane P2 and irradiates illumination light toward the object plane P2 from the N1 side of the optical axis Ao. The second oblique illumination unit 72 is positioned above the object plane P2 and irradiates illumination light toward the object plane P2 from the N2 side of the optical axis Ao.

[0073] As described above, the imaging lens 33 forms an image of light from the object plane P1 or P2 on the solid-state imaging device 41 disposed on the image plane. Here, the optical paths to the solid-state imaging device 41 include a straight optical path Oo, a first oblique optical path Ov1, and a second oblique optical path Ov2.

[0074] Specifically, of the illumination light reflected from the object plane P1, the light traveling parallel to the Z direction from the object plane P1 is incident on the central portion 330 of the imaging lens 33 and is imaged by the imaging lens 33 onto the solid-state imaging element 41. Specifically, there is an optical path, or facing optical path Oo, for light emitted from the object plane P1 in the Z direction, via the imaging lens 33 and reaching the solid-state imaging element 41.

[0075] Furthermore, among the illumination light reflected from the object plane P2, the light traveling from the object plane P2 parallel to the first oblique direction V1 is guided by the first oblique optical system 61 to the peripheral portion 331 of the imaging lens 33, and is imaged by the imaging lens 33 onto the solid-state imaging element 41. Specifically, a first oblique optical path Ov1 is provided, which is an optical path for the light emitted from the object plane P2 in the first oblique direction V1 to reach the solid-state imaging element 41 via the first oblique optical system 61 and the imaging lens 33.

[0076] Furthermore, of the illumination light reflected from the object plane P2, the light traveling from the object plane P2 parallel to the second oblique direction V2 is guided by the second oblique optical system 62 to the peripheral portion 332 of the imaging lens 33, and is imaged by the imaging lens 33 onto the solid-state imaging element 41. Specifically, a second oblique optical path Ov2 is provided, which is an optical path for the light emitted from the object plane P2 in the second oblique direction V2 to reach the solid-state imaging element 41 via the second oblique optical system 62 and the imaging lens 33.

[0077] Furthermore, because the path from object plane P1 to photographic lens 33 in the orthogonal optical path Oo differs from the path from object plane P2 to photographic lens 33 in the first oblique optical path Ov1, object plane P1 and object plane P2 are offset in the Z direction. That is, object plane P1 is further away from photographic lens 33 than object plane P2.

[0078] The pattern illumination system 35 includes a first pattern illumination unit 81. The first pattern illumination unit 81 illuminates the object plane P1 with pattern light Lp1 for measuring three-dimensional shapes using the light section method. The pattern light Lp1 is a laser beam having a linear shape extending in a direction orthogonal to the scanning direction N and the Z direction. The first pattern illumination unit 81 is positioned on the N2 side of the optical axis Ao of the imaging lens 33 and emits the pattern light Lp1 incident on the object plane P1 along a first sectioning direction Q1 that is inclined relative to the Z direction. Furthermore, when viewed from above in the Z direction, the first sectioning direction Q1 is parallel to the scanning direction N, and the pattern light Lp1 enters the object plane P1 from the N2 side.

[0079] The pattern illumination system 35 also includes a second pattern illumination unit 82. The second pattern illumination unit 82 irradiates pattern light Lp2, used for measuring three-dimensional shapes using the optical section method, onto the object plane P1. The pattern light Lp2 is a laser beam having a linear shape extending in a direction perpendicular to the scanning direction N and the Z direction. The second pattern illumination unit 82 is positioned on the N1 side of the optical axis Ao of the imaging lens 33 and emits the pattern light Lp2 incident on the object plane P1 along a second sectioning direction Q2 that is inclined relative to the Z direction. Furthermore, when viewed from above in the Z direction, the second sectioning direction Q2 is parallel to the scanning direction N, and the pattern light Lp2 is incident on the object plane P1 from the N1 side.

[0080] Figure 5A This figure schematically illustrates a line image captured by the inspection head. The processing unit 91 causes the inspection head 3 to capture a linear line image I1 extending parallel to a perpendicular direction M, which is perpendicular to the scanning direction N. Specifically, light from the object plane P1 or the object plane P2 is imaged by the imaging lens 33 onto the solid-state imaging element 41. The solid-state imaging element 41 then captures the line image I1, which is composed of output data from each pixel corresponding to the line image I1. The line image I1 has a width of at least a predetermined number of pixels in the scanning direction N.

[0081] Figure 5B This diagram schematically illustrates the relationship between the region of interest (ROI) set for the solid-state imaging element and the optical filter. As described above, the solid-state imaging element 41 captures light reaching it via the facing optical path Oo, the first oblique optical path Ov1, and the second oblique optical path Ov2. In contrast, the processing unit 91 sets the facing field of view Fo, the first oblique field of view Fv1, and the second oblique field of view Fv2, arranged in the scanning direction N, on the solid-state imaging element 41. The facing field of view Fo corresponds to the facing optical path Oo, and light reaching the solid-state imaging element 41 from the object plane P1 via the facing optical path Oo enters the facing field of view Fo. The first oblique field of view Fv1 corresponds to the first oblique optical path Ov1, and light reaching the solid-state imaging element 41 from the object plane P2 via the first oblique optical path Ov1 enters the first oblique field of view Fv1. The second oblique viewing area Fv2 is a region of interest corresponding to the second oblique optical path Ov2 , and light reaching the solid-state imaging element 41 from the object plane P2 via the second oblique optical path Ov2 enters the second oblique viewing area Fv2 .

[0082] In addition, as described above, an optical filter 45 is arranged in a manner opposite to the solid-state imaging element 41. The optical filter 45 has two bandpass filters 451 and 452 that selectively allow light of different wavelengths to pass through. The bandpass filter 451 allows the pattern light Lp1 and Lp2 to pass through, while limiting the transmission of the illumination light Lo, Lv1, and Lv2. The bandpass filter 452 allows the illumination light Lo, Lv1, and Lv2 to pass through, while limiting the transmission of the pattern light Lp1 and Lp2. In addition, in Figure 5B In FIG, the band-pass filter 451 and the band-pass filter 452 are distinguished by different shading (diagonal shading, dot shading).

[0083] The bandpass filter 452 is provided so as to overlap the entire first oblique viewing area Fv1. Therefore, the bandpass filter 452 allows the illumination lights Lo, Lv1, and Lv2 to enter the first oblique viewing area Fv1, while limiting the incidence of the pattern lights Lp1 and Lp2 on the first oblique viewing area Fv1.

[0084] Furthermore, the bandpass filter 452 is provided so as to overlap the entire second oblique viewing area Fv2. Therefore, the bandpass filter 452 allows the illumination lights Lo, Lv1, and Lv2 to enter the second oblique viewing area Fv2, while limiting the incidence of the pattern lights Lp1 and Lp2 on the second oblique viewing area Fv2.

[0085] Further, the band pass filter 452 is disposed in a manner of overlapping with the end portion region Foe disposed at both ends in the scanning direction N in the field of view region Fo. Therefore, the incidence of the illumination light Lo, Lv1, Lv2 to the end portion region Foe facing the field of view region Fo is allowed by the band pass filter 452, on the other hand, the incidence of the pattern light Lp1, Lp2 to the end portion region Foe facing the field of view region Fo is restricted by the band pass filter 452.

[0086] Further, the band pass filter 451 is disposed in a manner of overlapping with the central region Foc between the end portion regions Foe disposed at both ends in the scanning direction N in the field of view region Fo. Therefore, the incidence of the pattern light Lp1, Lp2 to the central region Foc facing the field of view region Fo is allowed by the band pass filter 451, on the other hand, the incidence of the illumination light Lo, Lv1, Lv2 to the central region Foc facing the field of view region Fo is restricted by the band pass filter 451.

[0087] In this configuration, the arithmetic processing section 91 can acquire two-dimensional images of the workpiece W by imaging the workpiece W placed on the workpiece placement plane 12 from the Z direction, the first oblique direction V1, and the second oblique direction V2, respectively. Further, the image acquired by the one imaging of the inspection head 3 is a linear line image Il extending in a straight line in the orthogonal direction orthogonal to the scanning direction N. Therefore, the arithmetic processing section 91 moves (i.e., scans) the inspection head 3 with respect to the workpiece placement plane 12 and causes the inspection head 3 to image the line image Il multiple times, thereby acquiring a two-dimensional image composed of a plurality of line images Il.

[0088] In a case where the two-dimensional image from the Z direction is acquired, the arithmetic processing section 91 controls the Z-axis motor 26 in a manner that the object plane P1 coincides with the workpiece placement plane 12, thereby adjusting the position (i.e., height) of the inspection head 3 in the Z direction. Next, the arithmetic processing section 91 performs adjustment of the scanning direction N. For example, in a case where the two-dimensional image is acquired while moving the inspection head 3 in the X direction, the arithmetic processing section 91 controls the R-axis motor 27 in a manner that the scanning direction N coincides with the X direction, thereby adjusting the position (i.e., rotation angle) of the rotation direction R of the inspection head 3. Further, in a case where the two-dimensional image is acquired while moving the inspection head 3 in the Y direction, the arithmetic processing section 91 controls the R-axis motor 27 in a manner that the scanning direction N coincides with the Y direction, thereby adjusting the position of the rotation direction R of the inspection head 3. Further, in order to acquire the two-dimensional image, the direction in which the inspection head 3 is moved need not be parallel to the X direction or the Y direction, but can be inclined with respect thereto.

[0089] When the rotation angle of the inspection head 3 is adjusted, the processing unit 91 controls the head drive mechanism 2 so that the inspection head 3 moves in the scanning direction N and transmits a capture command Ci to the inspection head 3, instructing it to capture a line image Il, a two-dimensional image viewed from the Z direction. Upon receiving this capture command Ci, the inspection head 3 illuminates the coaxial illumination 511, irradiating the object plane P1 with illumination light Lo, and captures multiple line images Il based on the light that reaches the solid-state imaging device 41 via the facing optical path Oo. As described above, the light (light of the same wavelength as the illumination light) that passes through the facing optical path Oo reaches the end region Foe of the facing field of view Fo set on the solid-state imaging device 41. Therefore, the inspection head 3 captures multiple line images Il based on the end region Foe of the facing field of view Fo. In this way, the inspection head 3 acquires multiple line images Il (in other words, image data Di) and transmits them to the processing unit 91. Then, the calculation processing unit 91 arranges the plurality of line images I1 in the scanning direction N to obtain a two-dimensional image of the workpiece W viewed from the Z direction.

[0090] When acquiring a two-dimensional image from the first oblique direction V1, the processing unit 91 controls the Z-axis motor 26 so that the object plane P2 aligns with the workpiece mounting plane 12, thereby adjusting the position (i.e., height) of the inspection head 3 in the Z direction. Next, the processing unit 91 adjusts the scanning direction N. Once the rotation angle of the inspection head 3 is adjusted, the processing unit 91 controls the head drive mechanism 2 to move the inspection head 3 in the scanning direction N and transmits an imaging command Ci to the inspection head 3, instructing it to capture a line image I1 for acquiring a two-dimensional image from the first oblique direction V1. Upon receiving this imaging command Ci, the inspection head 3 activates the coaxial illumination 511, irradiating the object plane P2 with illumination light Lv1, and captures multiple line images I1 based on the light that reaches the solid-state imaging device 41 via the first oblique optical path Ov1. As described above, the light (light of the same wavelength as the illumination light) that has passed through the first oblique optical path Ov1 reaches the first oblique field of view Fv1 set on the solid-state imaging device 41. Therefore, the inspection head 3 captures the line image I1 multiple times based on the first oblique viewing field Fv1. This way, the inspection head 3 acquires multiple line images I1 (in other words, image data Di) and transmits them to the processing unit 91. The processing unit 91 then arranges the multiple line images I1 in the scanning direction N to acquire a two-dimensional image of the workpiece W viewed from the first oblique direction V1.

[0091] When acquiring a two-dimensional image from the second oblique direction V2, the processing unit 91 controls the Z-axis motor 26 so that the object plane P2 aligns with the workpiece mounting plane 12, thereby adjusting the position (i.e., height) of the inspection head 3 in the Z direction. Next, the processing unit 91 adjusts the scanning direction N. When the rotation angle of the inspection head 3 is adjusted, the processing unit 91 controls the head drive mechanism 2 so that the inspection head 3 moves in the scanning direction N and transmits an imaging command Ci to the inspection head 3, instructing it to capture a line image I1 for acquiring a two-dimensional image from the second oblique direction V2. Upon receiving this imaging command Ci, the inspection head 3 activates the coaxial illumination 511, irradiating the object plane P2 with illumination light Lv2, and captures multiple line images I1 based on the light that reaches the solid-state imaging device 41 via the second oblique optical path Ov2. As described above, the light (light of the same wavelength as the illumination light) that has passed through the second oblique optical path Ov2 reaches the second oblique field of view Fv2 set on the solid-state imaging device 41. Therefore, the inspection head 3 captures the line image I1 multiple times based on the second oblique viewing field Fv2. In this way, the inspection head 3 obtains multiple line images I1 (in other words, image data Di) and transmits them to the processing unit 91. The processing unit 91 then arranges the multiple line images I1 in the scanning direction N to obtain a two-dimensional image of the workpiece W viewed from the second oblique direction V2.

[0092] Furthermore, the acquisition of a two-dimensional image from the first oblique direction V1 and the acquisition of a two-dimensional image from the second oblique direction V2 are performed so that the same object plane P2 is aligned with the workpiece mounting plane 12. Therefore, the capture of the line image I1 constituting the two-dimensional image from the first oblique direction V1 and the capture of the line image I1 constituting the two-dimensional image from the second oblique direction V2 can be performed in parallel while the inspection head 3 is moved in the scanning direction N.

[0093] In this configuration, the processing unit 91 can capture the workpiece W placed on the workpiece mounting plane 12 from the Z direction to obtain a three-dimensional image of the workpiece W. Furthermore, the image captured by the inspection head 3 in a single capture is a linear image I1 extending in a direction orthogonal to the scanning direction N. Therefore, the processing unit 91 moves the inspection head 3 relative to the workpiece mounting plane 12 (i.e., scans) while causing the inspection head 3 to capture the line image I1 multiple times, thereby obtaining a three-dimensional image composed of multiple line images I1.

[0094] Figure 6A 、 Figure 6B as well as Figure 6C This is a diagram schematically illustrating a first example of a method for acquiring a three-dimensional image. Figure 6A 、 Figure 6B as well as Figure 6CThe workpiece W shown has a length Wx in the X direction, a width Wy in the Y direction, and a height Wz in the Z direction. Pattern light Lp1 is irradiated on the workpiece W from a first cutting direction Q1. In the examples shown in these figures, the scanning direction N is set to the X direction.

[0095] Therefore, the X-direction position Xh of the pattern light Lp1 on the upper surface of the workpiece W and the X-direction position Xl of the pattern light Lp1 on the workpiece mounting plane 12 differ depending on the height difference between the upper surface of the workpiece W and the workpiece mounting plane 12. In this case, the height Wx of the workpiece W is given by the following equation using the angle θ between the pattern light Lp1 and the workpiece mounting plane 12.

[0096] Wx=|Xh-Xl|×tanθ

[0097] Therefore, the calculation processing unit 91 can capture a plurality of line images I1, obtain information indicating the height of the workpiece W based on the position of the irradiation pattern light Lp1 in each line image I1, and acquire a three-dimensional image of the workpiece W.

[0098] Specifically, when acquiring a three-dimensional image, the processing unit 91 controls the Z-axis motor 26 so that the object plane P1 aligns with the workpiece mounting plane 12, thereby adjusting the position (i.e., height) of the inspection head 3 in the Z direction. Next, the processing unit 91 adjusts the scanning direction N. Once the rotation angle of the inspection head 3 is adjusted, the processing unit 91 controls the head drive mechanism 2 to move the inspection head 3 in the scanning direction N and transmits an imaging command Ci to the inspection head 3, instructing it to capture a line image I1 for acquiring a three-dimensional image. Upon receiving this imaging command Ci, the inspection head 3 illuminates the first pattern irradiation unit 81, irradiating the object plane P1 with pattern light Lp1, and captures multiple line images I1 based on light that reaches the solid-state imaging device 41 via the facing optical path Oo. As described above, the light (light of the same wavelength as the pattern light) that has passed through the facing optical path Oo reaches the center region Foc of the facing field of view Fo set on the solid-state imaging device 41. Therefore, the inspection head 3 captures the line image I1 multiple times based on the central area Foc facing the field of view Fo. In this way, the inspection head 3 obtains multiple line images I1 (in other words, image data Di) and sends them to the calculation processing unit 91. The calculation processing unit 91 then arranges the multiple line images I1 in the scanning direction N to obtain a three-dimensional image of the workpiece W viewed from the Z direction.

[0099] Figure 7 FIG is a diagram schematically illustrating a second example of a method for obtaining a three-dimensional image. Figure 7 , a plurality of pixel columns 411 to 415 are described, each consisting of a plurality of pixels arranged in a direction M perpendicular to the scanning direction N. In particular, Figure 7, a state in which the pixel rows 411 to 415 sequentially capture images of the target position Nt each time the inspection head 3 moves by one pixel of the solid-state imaging element 41 in the scanning direction N is shown in time series (times T1 to T5 ).

[0100] exist Figure 6A 、 Figure 6B as well as Figure 6C In the example of , a three-dimensional image of the workpiece W is obtained based on the difference in the irradiation position of the pattern light Lp1 in the scanning direction N (X direction). Figure 7 In the example of , a three-dimensional image of the workpiece W is acquired based on the difference in timing of capturing the pattern light Lp1.

[0101] At time T1 , the pixel row 411 captures the target position Nt. At time T1 , the pattern light Lp1 is not irradiated onto the target position Nt, and the image captured by the pixel row 411 does not include the pattern light Lp1 .

[0102] At time T2, after time T1, the pixel array 412 captures the target position Nt. At time T2, the pattern light Lp1 irradiating the upper surface of the workpiece W is located at the target position Nt. Therefore, among the multiple pixels in the pixel array 412, the pixels corresponding to the upper surface of the workpiece W capture the pattern light Lp1, while the pixels corresponding to the workpiece mounting plane 12 do not capture the pattern light Lp1.

[0103] At time T3 after time T2 , the pixel row 413 captures the target position Nt. At time T3 , the pattern light Lp1 is not irradiated onto the target position Nt, and the image captured by the pixel row 413 does not include the pattern light Lp1 .

[0104] At time T4, after time T3, pixel array 414 captures the target position Nt. At time T4, pattern light Lp1 irradiating workpiece mounting plane 12 is located at target position Nt. Therefore, among the multiple pixels in pixel array 414, the pixels corresponding to workpiece mounting plane 12 capture pattern light Lp1, while the pixels corresponding to the top surface of workpiece W do not capture pattern light Lp1.

[0105] At time T5 after time T4, the pixel array 415 captures the target position Nt. At time T5, the pattern light Lp1 is not irradiated onto the target position Nt, and the image captured by the pixel array 415 does not include the pattern light Lp1.

[0106] Thus, the times T2 and T4 at which the pattern light Lp1 irradiating the same target position Nt is captured differ depending on the height (the upper surface of the workpiece W, the workpiece mounting plane 12) at which the pattern light Lp1 is irradiated. The difference between the times T2 and T4 corresponds to the distance in the scanning direction N between the pixel 412 that detected the pattern light Lp1 at time T2 and the pixel 414 that detected the pattern light Lp1 at time T4. Therefore, it is possible to use Figures 6A to 6C The principle of the description likewise takes a three-dimensional image of the workpiece W.

[0107] In addition, in the example described above, the pattern light Lpl is irradiated to the workpiece W to take a three-dimensional shape. However, the pattern light Lp2 can be irradiated to the workpiece W to likewise take a three-dimensional shape.

[0108] In the inspection device 1 described above, the photographing lens 33 is provided so as to face the workpiece placement plane 12 (placement plane) on which the workpiece W (inspection object) is placed from the Z direction (front direction). The photographing lens 33 images the light Lo, Lvl, Lpl incident from the object side on which the workpiece placement plane 12 is provided, on the solid-state imaging element 41 (imaging element) of the camera 32 provided on the image side. Further, the first oblique optical system 61 is provided which guides light toward the first oblique direction Vl inclined with respect to the Z direction to the photographing lens 33. Then, the light Lo, Lpl reflected from the workpiece placement plane 12 toward the Z direction is imaged on the solid-state imaging element 41 by the photographing lens 33. In addition, the light Lvl reflected from the workpiece placement plane 12 toward the first oblique direction Vl is guided to the photographing lens 33 by the first oblique optical system 61 and imaged on the solid-state imaging element 41 by the photographing lens 33. That is, each light reflected from the workpiece placement plane 12 toward a plurality of directions (the Z direction and the first oblique direction Vl) is imaged on the solid-state imaging element 41 of the same camera 32. Therefore, the illumination light Lo, Lvl can be irradiated to the workpiece W placed on the workpiece placement plane 12, and the camera 32 can be used to respectively take the illumination light Lo reflected toward the Z direction and the illumination light Lvl reflected toward the first oblique direction Vl. In addition, the pattern light Lpl can be irradiated to the workpiece W, and the camera 32 can be used to take the pattern light Lpl reflected toward the Z direction. In this way, the camera 32 can be used to perform the photographing from a plurality of directions (the Z direction and the first oblique direction Vl) for taking a two-dimensional image and the photographing for taking a three-dimensional image.

[0109] The illumination system 34 also includes a coaxial illumination unit 51 that generates coaxial light Lc that passes through the imaging lens 33 in the Z direction from the image side, opposite the object side, toward the object side. The first oblique optical system 61 redirects a portion of the coaxial light Lc toward the first oblique direction V1, thereby generating illumination light Lv1 that travels from the first oblique direction V1 toward the workpiece mounting plane 12. The imaging lens 33 emits light from the coaxial light Lc that is different from the portion in the Z direction, thereby generating illumination light Lo that travels from the Z direction toward the workpiece mounting plane 12. With this configuration, the illumination light Lv1 is irradiated from the first oblique direction V1 toward the workpiece mounting plane 12 by the first oblique optical system 61. Furthermore, the illumination light Lv1, which is reflected from the workpiece mounting plane 12 toward the first oblique direction V1 by the imaging lens 33 and then returned to the first oblique optical system 61, is formed into an image on the solid-state imaging device 41. That is, illumination with illumination light Lv1 from the first oblique direction V1 and imaging with illumination light Lv1 from the first oblique direction V1 are performed via the common first oblique optical path Ov1. Furthermore, illumination light Lo can be irradiated onto the workpiece mounting plane 12 from the Z direction via the imaging lens 33. The illumination light Lo, reflected from the workpiece mounting plane 12 in the Z direction by the imaging lens 33 and returned to the imaging lens 33, is imaged onto the solid-state imaging device 41. In other words, illumination with illumination light Lo from the Z direction and imaging with illumination light Lo from the Z direction are performed via the common facing optical path Oo. By thus commonalizing the optical path, the inspection apparatus 1 can be made more compact.

[0110] The camera 33 also includes a second oblique optical system 62 that guides light directed from the workpiece mounting plane 12 toward a second oblique direction V2 tilted relative to the Z direction toward the imaging lens 33. Furthermore, the camera 33 includes a second pattern irradiation unit 82 that irradiates the workpiece mounting plane 12 with a linear pattern light Lp2 from a second cutting direction Q2 tilted relative to the Z direction, for use in measuring the shape of the workpiece W mounted on the workpiece mounting plane 12 using the light section method. With respect to the optical axis Ao of the imaging lens 33, the first oblique optical system 61 is positioned on the N1 side (one side), while the first pattern irradiation unit 81 is positioned on the N2 side (the other side). Furthermore, the second oblique optical system 62 is positioned on the N2 side, while the second pattern irradiation unit 82 is positioned on the N1 side. With this configuration, a single camera 32 can capture images from multiple directions (the Z direction, the first oblique direction V1, and the second oblique direction V2) to obtain a two-dimensional image, and capture images from multiple directions (the first oblique direction V1 and the second oblique direction V2) to obtain a three-dimensional image using the pattern light Lp1 and Lp2.

[0111] Further, the operation processing section 91 (control section) is provided which sets the direct view field region Fo and the first oblique view field region Fv1 (oblique view field region) of the solid-state imaging element 41. In contrast, the photographing lens 33 images light emitted from the work placement plane 12 in the Z direction on the direct view field region Fo of the solid-state imaging element 41, and images light emitted from the work placement plane 12 in the first oblique direction V1 and guided by the first oblique optical system 61 on the first oblique view field region Fv1 of the solid-state imaging element 41. Thus, by one solid-state imaging element 41 of one camera 32, it is possible to perform photographing from a plurality of directions (the Z direction and the first oblique direction V1) for acquiring a two-dimensional image and photographing for acquiring a three-dimensional image.

[0112] Further, the Y-axis motor 24 and the X-axis motor 25 (scanning drive section) are provided which relatively move the inspection head 3 in the scanning direction N with respect to the work placement plane 12. The operation processing section 91 moves the inspection head 3 in the scanning direction N by the head driving mechanism 2, and causes the solid-state imaging element 41 to perform photographing of a line image Il constituted by illumination light Lv1 imaged on the first oblique view field region Fv1 a plurality of times, thereby acquiring a plurality of line images Il (oblique view field illumination image), and acquires a two-dimensional image of the work W placed on the work placement plane 12 by arranging the plurality of line images Il. In this structure, it is possible to suppress the width of the line image Il acquired at one time. As a result, when photographing is performed from the first oblique direction V1, it is possible to suppress the difference in telecentricity between the front side and the back side of the photographing lens 33 in the oblique direction to photograph a two-dimensional image of the work W.

[0113] Further, between the solid-state imaging element 41 and the photographing lens 33, a band pass filter 452 (illumination light transmission filter) is provided which is arranged so as to at least partially overlap the first oblique view field region Fv1. This band pass filter 452 allows transmission of light of the wavelength of the illumination light Lv1, and on the other hand, restricts transmission of light of the wavelength of the pattern light Lp1. In contrast, the operation processing section 91 acquires a line image Il constituted by light imaged on a region of the first oblique view field region Fv1 which overlaps the band pass filter 452. In this structure, it is possible to suppress the influence of the pattern light Lp1 by the band pass filter 452, and appropriately acquire a line image Il based on the illumination light Lv1.

[0114] Further, a Y-axis motor 24 and an X-axis motor 25 (scanning drive section) that move the inspection head 3 in the scanning direction N with respect to the work placement plane 12 are provided. The arithmetic processing section 91 moves the inspection head 3 in the scanning direction N by the head drive mechanism 2, and causes the solid-state imaging element 41 to perform imaging of the line image Il constituted by the pattern light Lp1 imaged in the field-of-view region Fo a plurality of times, thereby acquiring a plurality of line images Il (field-of-view pattern image), and acquires a three-dimensional image of the work W placed on the work placement plane 12 by arranging the plurality of line images Il. In this configuration, the width of the line image Il acquired at one time can be suppressed. As a result, when imaging from the first inclined direction V1, the three-dimensional image of the work W can be imaged while suppressing the difference in telecentricity of the imaging lens 33 between the front side and the back side in the inclined direction.

[0115] Further, between the solid-state imaging element 41 and the imaging lens 33, a band-pass filter 451 (pattern light transmission filter) configured to be disposed at least partially overlapping the field-of-view region Fo is provided. The band-pass filter 451 allows the transmission of light of the wavelength of the pattern light Lp1, and on the other hand, restricts the transmission of light of the wavelength of the illumination light Lv1. In contrast, the arithmetic processing section 91 acquires an image constituted by light imaged in a region of the field-of-view region Fo overlapping the band-pass filter 451 as the line image Il. In this configuration, the influence of the illumination light Lo can be suppressed by the band-pass filter 451, and the line image Il based on the pattern light Lp1 can be appropriately acquired.

[0116] Further, between the solid-state imaging element 41 and the imaging lens 33, a band-pass filter 452 configured to be disposed adjacent to the band-pass filter 451 and partially overlapping the field-of-view region Fo is provided. The band-pass filter 452 allows the transmission of light of the wavelength of the illumination light Lo, and on the other hand, restricts the transmission of light of the wavelength of the pattern light Lp1. In contrast, the arithmetic processing section 91 relatively moves the inspection head 3 in the scanning direction N by the head drive mechanism 2, and causes the solid-state imaging element 41 to perform imaging of the line image Il constituted by the illumination light Lo imaged in a region of the field-of-view region Fo overlapping the band-pass filter 452 a plurality of times, thereby acquiring a plurality of line images Il (field-of-view illumination image), and acquires a two-dimensional image of the work W placed on the work placement plane 12 by arranging the plurality of line images Il. In this configuration, the width of the line image Il acquired at one time can be suppressed. As a result, the two-dimensional image of the work W can be imaged while suppressing the difference in telecentricity of the imaging lens 33 between the front side and the back side in the inclined direction at the time of imaging. Furthermore, the influence of the pattern light Lp1 can be suppressed by the band-pass filter 452, and the line image Il based on the illumination light Lo can be appropriately acquired.

[0117] The inspection head 3 is also equipped with a Y-axis motor 24 and an X-axis motor 25 (scanning drive unit) that move the inspection head 3 in the scanning direction N relative to the workpiece mounting plane 12, and an R-axis motor 27 (rotation drive unit) that rotates the inspection head 3 about a rotation axis Az parallel to the Z direction. This configuration allows the inspection head 3 to be rotated appropriately in response to changes in the scanning direction N.

[0118] Thus, in the above-described embodiment, the inspection device 1 corresponds to an example of the “inspection device” of the present invention, the workpiece mounting plane 12 corresponds to an example of the “mounting plane” of the present invention, the Y-axis motor 24 and the X-axis motor 25 correspond to an example of the “scanning drive unit” of the present invention, the R-axis motor 27 corresponds to an example of the “rotation drive unit” of the present invention, the camera 32 corresponds to an example of the “camera” of the present invention, the imaging lens 33 corresponds to an example of the “imaging lens” of the present invention, the illumination system 34 corresponds to an example of the “illumination system” of the present invention, the solid-state imaging element 41 corresponds to an example of the “imaging element” of the present invention, the bandpass filter 451 corresponds to an example of the “pattern light transmission filter” of the present invention, the bandpass filter 452 corresponds to an example of the “illumination light transmission filter” of the present invention, the coaxial illumination unit 51 corresponds to an example of the “coaxial illumination unit” of the present invention, the first tilting optical system 61 corresponds to an example of the “first tilting optical system” of the present invention, the second tilting optical system 62 corresponds to an example of the “second tilting optical system” of the present invention, the first pattern irradiation unit 81 corresponds to an example of the “first pattern irradiation unit” of the present invention, the second pattern irradiation unit 82 corresponds to an example of the “second pattern irradiation unit” of the present invention, and the arithmetic processing unit 41 corresponds to an example of the “imaging element” of the present invention. The processing unit 91 is equivalent to an example of the “control unit” of the present invention, the directly facing field of view area Fo is equivalent to an example of the “directly facing field of view area” of the present invention, the first oblique field of view area Fv1 or the second oblique field of view area Fv2 is equivalent to an example of the “oblique field of view area” of the present invention, the line image Il is equivalent to an example of the “oblique field of view illumination image” of the present invention, the line image Il is equivalent to an example of the “directly facing field of view pattern image” of the present invention, the line image Il is equivalent to an example of the “directly facing field of view illumination image” of the present invention, the coaxial light Lc is equivalent to an example of the “coaxial light” of the present invention, and the illumination lights Lo, Lv1, and Lv2 are equivalent to the illumination lights of the present invention. The pattern lights Lp1 and Lp2 are equivalent to an example of “pattern light” of the present invention, the scanning direction N is equivalent to an example of the “scanning direction” of the present invention, the first cutting direction Q1 is equivalent to an example of the “first cutting direction” of the present invention, the second cutting direction Q2 is equivalent to an example of the “second cutting direction” of the present invention, the first inclined direction V1 is equivalent to an example of the “first inclined direction” of the present invention, the second inclined direction V2 is equivalent to an example of the “second inclined direction” of the present invention, the workpiece W is equivalent to an example of the “inspection object” of the present invention, and the Z direction is equivalent to an example of the “facing direction” of the present invention.

[0119] The present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described embodiment without departing from the spirit of the present invention. For example, the following modifications are possible.

[0120] Figure 8 This is a side view schematically showing the structure of the second example of the inspection head. Figure 3 The following description will focus on the differences from the first example. Similar points to the first example are denoted by corresponding reference numerals, and their description will be omitted as appropriate. The first example differs from the second example in that an optical path adjustment member 63 is provided for the facing optical path Oo. The optical path adjustment member 63 adjusts the propagation of light from the object plane P1 to the photographic lens 33 in the facing optical path Oo.

[0121] Specifically, the optical path adjustment member 63 includes a reflecting member 631 for reflecting light emitted from the object plane P1 in the Z direction toward the N2 side of the scanning direction N; a reflecting member 632 for reflecting the light from the reflecting member 631 upward in the Z direction; a reflecting member 633 for reflecting the light from the reflecting member 632 toward the N1 side of the scanning direction N; and a reflecting member 634 for reflecting the light from the reflecting member 633 upward in the Z direction and guiding it toward the imaging lens 33. The reflecting members 631, 632, 633, and 634 are, for example, mirrors or prisms.

[0122] In this way, the optical path adjustment member 63 detours the light that reaches the taking lens 33 from the object plane P1 in the facing optical path Oo. Here, detour means that, rather than directing the light from the object plane P1 in the Z direction straight to the taking lens 33, the light emitted from the object plane P1 in the Z direction is guided in a direction different from the Z direction, then travels in the Z direction and enters the taking lens 33. As a result, the object plane P1 corresponding to the facing optical path Oo and the object plane P2 corresponding to the first oblique optical path Ov1 and the second oblique optical path Ov2 coincide with each other.

[0123] By the way, in Figure 8 In the example shown in FIG. 1 , the first oblique direction V1 coincides with the second cutting direction Q2, and the reflective component 613 of the first oblique optical path Ov1 is located on the optical path of the pattern light Lp2. Therefore, the reflective component 613 needs to reflect light from the object plane P2 toward the reflective component 612, while transmitting light from the second pattern illumination unit 82 toward the object plane P1. Therefore, a half mirror, for example, is used as the reflective component 613.

[0124] Furthermore, the second oblique direction V2 coincides with the first cutting direction Q1, and the reflective component 623 of the second oblique optical path Ov2 is located on the optical path of the pattern light Lp1. Therefore, the reflective component 623 needs to reflect light from the object plane P2 toward the reflective component 622, while transmitting light from the first pattern illumination unit 8182 toward the object plane P1. Therefore, a half mirror, for example, is used as the reflective component 623.

[0125] In this way, Figure 8 In this example, the optical path of light emitted from the workpiece mounting plane 12 in the Z direction, via the imaging lens 33, to the solid-state imaging device 41, namely, the object plane P1 corresponding to the optical path Oo, coincides with the optical path of light emitted from the workpiece mounting plane 12 in the first oblique direction V1, via the first oblique optical system 61 and the imaging lens 33, namely, the object plane P2 corresponding to the first oblique optical path Ov1. With this configuration, for example, irradiation and imaging of the workpiece W mounted on the workpiece mounting plane 12 with illumination light Lv1 and irradiation and imaging with pattern light Lp1 can be performed in parallel. This allows efficient acquisition of two-dimensional and three-dimensional images of the workpiece W.

[0126] Furthermore, the optical paths of light emitted from the workpiece mounting plane 12 in the second oblique direction V2, via the second oblique optical system 62 and the imaging lens 33, reaching the solid-state imaging element 41—namely, the object plane P2 of the second oblique optical path Ov2, the object plane P2 of the first oblique optical path Ov1, and the object plane P1 of the facing optical path Oo—are aligned. With this configuration, for example, irradiation / imaging of the workpiece W mounted on the workpiece mounting plane 12 with illumination light Lv1, irradiation / imaging with pattern light Lp1, and irradiation / imaging with pattern light Lp2 can be performed in parallel. This allows efficient acquisition of two-dimensional and three-dimensional images of the workpiece W.

[0127] Specifically, an optical path adjustment component 63 is provided, positioned between the workpiece mounting plane 12 and the imaging lens 33 in the facing optical path Oo. This optical path adjustment component 63 detours light traveling in the Z direction from the workpiece mounting plane 12 and then emits it in the Z direction toward the imaging lens 33, thereby aligning the object plane P1 of the facing optical path Oo with the object plane P2 of the first oblique optical path Ov1. With this configuration, for example, irradiation / imaging of a workpiece W mounted on the workpiece mounting plane 12 with illumination light Lv1 and irradiation / imaging with pattern light Lp1 can be performed simultaneously. Consequently, two-dimensional and three-dimensional images of the workpiece W can be efficiently acquired.

[0128] Figure 9A is a side view schematically showing the structure of a third example of an inspection head, Figure 9B It is schematically represented in Figure 9A Here, the optical path adjustment components used in the inspection head are shown. Figure 8The following description will focus on the differences from the second example. Similar points to the second example are denoted by corresponding reference numerals, and their description will be omitted as appropriate. The second example differs from the third example in that an optical path adjustment component 64 is provided in place of the optical path adjustment component 63. The optical path adjustment component 64 adjusts the path of light from the object plane P2 to the photographic lens 33 into a first oblique optical path Ov1 and a second oblique optical path Ov2, respectively.

[0129] like Figure 9A and Figure 9B As shown, an optical path adjustment member 64 is disposed on the image side of the photographic lens 33, specifically, between the optical filter 45 and the photographic lens 33. The optical path adjustment member 64 includes a glass plate 641 disposed relative to the first oblique optical path Ov1 and a glass plate 642 disposed relative to the second oblique optical path Ov2. The glass plates 641 and 642 have the same thickness G in the Z direction. Light traveling along the first oblique optical path Ov1 passes through the glass plate 641, then passes through the optical filter 45, and forms an image on the first oblique field of view Fv1 of the solid-state imaging element 41. Light traveling along the second oblique optical path Ov2 passes through the glass plate 642, then passes through the optical filter 45, and forms an image on the second oblique field of view Fv2 of the solid-state imaging element 41.

[0130] The glass plate 641 functions so that the optical path length on the image side of the taking lens 33 in the first oblique optical path Ov1 is longer than the optical path length on the image side of the taking lens 33 in the facing optical path Oo. Therefore, the optical path length on the object side of the taking lens 33 in the first oblique optical path Ov1 is shorter than the optical path length on the object side of the taking lens 33 in the facing optical path Oo. Similarly, the glass plate 642 functions so that the optical path length on the image side of the taking lens 33 in the second oblique optical path Ov2 is longer than the optical path length on the image side of the taking lens 33 in the facing optical path Oo. Therefore, the optical path length on the object side of the taking lens 33 in the second oblique optical path Ov2 is shorter than the optical path length on the object side of the taking lens 33 in the facing optical path Oo. As a result, the object plane P1 and the object plane P2 coincide with each other.

[0131] Here, the lens magnification m of the photographing lens 33 , the optical path difference ΔO1 between the first oblique optical path Ov1 on the object side and the facing optical path Oo, and the optical path difference ΔO2 between the first oblique optical path Ov1 on the image side and the facing optical path Oo satisfy the following relationship.

[0132] ΔO2=ΔO1×m 2

[0133] Furthermore, the thickness G of the glass plates 641 and 642 and the refractive index n of the glass plates 641 and 642 satisfy the following relationship.

[0134] G = ΔO2 / ((n-1) / n)

[0135] In this way, Figure 9A and Figure 9B In the example, a glass plate 641 is provided, positioned between the imaging lens 33 and the solid-state imaging device 41 in the first oblique optical path Ov1. This glass plate 641 allows light incident from the imaging lens 33 to propagate through the interior of the glass plate 641 and then be emitted toward the solid-state imaging device 41. This arrangement aligns the object plane P2 of the first oblique optical path Ov1 with the object plane P1 of the facing optical path Oo. With this configuration, for example, irradiation and imaging of a workpiece W placed on the workpiece placement plane 12 with illumination light Lv1 and irradiation and imaging with pattern light Lp1 can be performed simultaneously. This allows efficient acquisition of two-dimensional and three-dimensional images of the workpiece W.

[0136] Similarly, a glass plate 642 is provided, positioned between the imaging lens 33 and the solid-state imaging device 41 in the second oblique optical path Ov2. This glass plate 642 allows light incident from the imaging lens 33 to propagate through the interior of the glass plate 642 and then be emitted toward the solid-state imaging device 41. This arrangement aligns the object plane P2 of the second oblique optical path Ov2 with the object plane P1 of the facing optical path Oo. With this configuration, for example, irradiation and imaging of a workpiece W placed on the workpiece placement plane 12 with illumination light Lv2 and irradiation and imaging with pattern light Lp1 can be performed simultaneously. This allows efficient acquisition of two-dimensional and three-dimensional images of the workpiece W.

[0137] In the first example, pattern light Lp1 incident on object plane P1 from a first oblique direction V1 and diffusely reflected in the Z direction is imaged on the solid-state imaging device 41 via the facing optical path Oo, thereby capturing a line image Il. Similarly to the first example, in the second and third examples, line images Il based on diffusely reflected pattern light Lp1 can also be captured. However, in the second and third examples, line images Il based on pattern light Lp1 that is regularly reflected from object plane P1 can also be captured.

[0138] Specifically, the first pattern irradiation unit 81 and the first oblique optical system 61 are arranged so that the direction in which pattern light Lp1 incident on the workpiece mounting plane 12 from the first cutting direction Q1 is regularly reflected by the workpiece mounting plane 12 coincides with the first oblique direction V1. With this configuration, the workpiece W having specular reflection properties can be irradiated with the pattern light Lp1 from the first cutting direction Q1, and the pattern light Lp1 specularly reflected by the workpiece W is guided to the imaging lens 33 by the first oblique optical system 61. Consequently, a three-dimensional image of the workpiece W having specular reflection properties can be obtained using a single camera 32.

[0139] Furthermore, the second pattern irradiation unit 82 and the second oblique optical system 62 are arranged so that the direction of regular reflection of the pattern light Lp2 incident on the workpiece mounting plane 12 from the second cutting direction Q2 coincides with the second oblique direction V2. With this configuration, the workpiece W having specular reflection properties can be irradiated with the pattern lights Lp1 and Lp2 from the first and second cutting directions Q1 and Q2, respectively. The pattern lights Lp1 and Lp2, after specular reflection from the workpiece W, are then guided to the imaging lens 33 by the first and second oblique optical systems 61 and 62. Consequently, a three-dimensional image of the workpiece W having specular reflection properties can be obtained using a single camera 32.

[0140] Figure 10 This is a side view schematically showing the structure of the fourth example of the inspection head. Figure 8 The following description will focus on the differences from the second example, with common points with the second example being denoted by corresponding reference numerals and their description omitted as appropriate. The second example differs from the fourth example in that the first tilting optical system 61 and the second pattern irradiation unit 82 are arranged so that the first tilting direction V1 and the second cutting direction Q2 do not coincide with each other, and the second tilting optical system 62 and the first pattern irradiation unit 81 are arranged so that the second tilting direction V2 and the first cutting direction Q1 do not coincide with each other.

[0141] Specifically, the angle between the first oblique direction V1 and the workpiece mounting plane 12 differs from the angle between the second cutting direction Q2 and the workpiece mounting plane 12, and the angle between the second oblique direction V2 and the workpiece mounting plane 12 differs from the angle between the first cutting direction Q1 and the workpiece mounting plane 12. Therefore, the reflective member 613 does not overlap with the optical path of the pattern light Lp2 emitted from the second pattern illumination unit 82 toward the object plane P2, and the reflective member 623 does not overlap with the optical path of the pattern light Lp1 emitted from the first pattern illumination unit 81 toward the object plane P2. As a result, the pattern lights Lp1 and Lp2 irradiated onto the workpiece mounting plane 12 do not pass through the reflective members 613 and 623 (half-mirror), reducing the light intensity of the pattern lights Lp1 and Lp2. This allows for efficient illumination of the required light intensity of the pattern lights Lp1 and Lp2, and for acquisition of a three-dimensional image of the workpiece W.

[0142] Figure 11 This is a diagram schematically showing a modified example of the relationship between the region of interest set for the solid-state imaging element and the optical filter. Figure 5B The following description will focus on the differences between the examples, and the common points will be marked with corresponding symbols and the description will be omitted as appropriate. Figure 5B The difference from the example is that bandpass filters 451 and 452 are provided for both the first oblique viewing area Fv1 and the second oblique viewing area Fv2.

[0143] That is, the band pass filter 452 is disposed in a manner of overlapping with the end region Fve disposed at both ends in the scanning direction N in the first oblique field region Fv1. Therefore, the incidence of the illumination light Lo, Lv1, Lv2 to the end region Fve of the first oblique field region Fv1 is allowed by the band pass filter 452, on the other hand, the incidence of the pattern light Lp1, Lp2 to the end region Fve of the first oblique field region Fv1 is restricted by the band pass filter 452.

[0144] Further, the band pass filter 451 is disposed in a manner of overlapping with the central region Fvc between the end regions Fve disposed at both ends in the scanning direction N in the first oblique field region Fv1. Therefore, the incidence of the pattern light Lp1, Lp2 to the central region Fvc of the first oblique field region Fv1 is allowed by the band pass filter 451, on the other hand, the incidence of the illumination light Lo, Lv1, Lv2 to the central region Fvc of the first oblique field region Fv1 is restricted by the band pass filter 451.

[0145] That is, between the solid-state imaging element 41 and the photographing lens 33, the band pass filter 451 (pattern light transmission filter) is provided in a manner of being disposed in partial overlap with the first oblique field region Fv1 (oblique field region) and adjacent to the band pass filter 452. The band pass filter 451 allows the transmission of light of the wavelength of the pattern light Lp1, Lp2, on the other hand, restricts the transmission of light of the wavelength of the illumination light Lo, Lv1, Lv2. To the contrary, the arithmetic processing section 91 moves the inspection head 3 in the scanning direction N by the Y-axis motor 24 and the X-axis motor 25, and causes the solid-state imaging element 41 to perform the photographing of the line image Il constituted by the pattern light Lp1, Lp2 imaged in the central region Fvc of the first oblique field region Fv1 overlapping with the band pass filter 451 a plurality of times, thereby acquires a plurality of line images Il (oblique field pattern image), acquires the three-dimensional image of the workpiece W placed on the workpiece placement plane 12 by arranging the plurality of line images Il. In this structure, it is possible to suppress the width of the line image Il acquired at one time. As a result, when the photographing is performed from the first oblique direction V1, it is possible to suppress the difference in the telecentricity between the front side and the back side in the oblique direction of the photographing lens 33 to photograph the three-dimensional image of the workpiece W. Further, it is possible to suppress the influence of the illumination light Lo, Lv1, Lv2 by the band pass filter 451 and to appropriately acquire the line image Il.

[0146] Further, in the second oblique field region Fv2, the band pass filter 451 and the band pass filter 452 are also disposed in the same manner as the first oblique field region Fv1. Then, the arithmetic processing section 91 performs the same control as the first oblique field region Fv1 on the second oblique field region Fv2.

[0147] Furthermore, deformations other than those described above can be applied. For example, the coaxial illumination 511 may emit visible light of R (red), G (green), and B (blue). In this case, the visible light of each of R, G, and B can be used to capture the line images I1 of each of R, G, and B. In addition, in order to separate and capture the line images I1 of each position of R, G, and B, the inspection head 3 may be configured to image R, G, and B respectively on different regions of interest of the solid-state imaging element 41. Alternatively, color filters of R, G, and B may be provided in the optical filter 45, and R, G, and B may be sequentially illuminated in the coaxial illumination 511 to capture the line images I1.

[0148] Alternatively, instead of driving the inspection head 3 , the workpiece mounting plane 12 may be driven to move the inspection head 3 in the scanning direction N relative to the workpiece mounting plane 12 .

[0149] Furthermore, the specific configurations of the first tilting optical system 61 and the second tilting optical system 62 are not limited to the above-described examples, and the number and arrangement of reflective components and the like can be appropriately changed.

[0150] Marking Description

[0151] 1…Inspection device;

[0152] 12…workpiece mounting plane (mounting plane);

[0153] 24…Y-axis motor (scanning drive unit);

[0154] 25…X-axis motor (scanning drive unit);

[0155] 27…R-axis motor (rotation drive unit);

[0156] 32…camera;

[0157] 33…shooting shots;

[0158] 34…Lighting system;

[0159] 41… solid-state imaging element (imaging element);

[0160] 451…Bandpass filter (pattern light transmission filter);

[0161] 452…Bandpass filter (illumination light transmission filter);

[0162] 51…coaxial lighting unit;

[0163] 61…a first tilted optical system;

[0164] 62…second tilt optical system;

[0165] 81 ...a first pattern irradiation portion;

[0166] 82 ... a second pattern irradiation portion;

[0167] 91 ...arithmetic processing unit (control unit);

[0168] Fo…facing the field of vision;

[0169] Fv1…first oblique visual field area (oblique visual field area);

[0170] Fv2…second oblique visual field area (oblique visual field area);

[0171] I1… line images (oblique field of view illumination image, frontal field of view pattern image, frontal field of view illumination image);

[0172] Lc…coaxial light;

[0173] Lo, Lv1, Lv2…illumination light;

[0174] Lp1, Lp2…pattern light;

[0175] N…scanning direction;

[0176] Q1…first cutting direction;

[0177] Q2…second cutting direction;

[0178] V1…first tilt direction;

[0179] V2…second tilt direction;

[0180] W…workpiece (inspection object);

[0181] Z...Z direction (facing direction).

Claims

1. An inspection device comprising: A camera having an imaging element for capturing received light; The photographing lens faces a mounting plane provided on the object side and on which the inspection object is mounted, from a predetermined facing direction; a first oblique optical system for guiding light from the mounting plane in a first oblique direction oblique with respect to the facing direction to the photographic lens; an illumination system for generating illumination light directed toward the mounting plane; as well as a first pattern irradiation unit for irradiating the mounting plane with linear pattern light from a first cutting direction inclined with respect to the facing direction for measuring the shape of the inspection object mounted on the mounting plane by a light section method; The photographing lens forms an image on the photographing element of light reflected from the mounting plane in the facing direction, and forms an image on the photographing element of light reflected from the mounting plane in the first oblique direction and guided by the first oblique optical system.

2. The inspection device according to claim 1, wherein: The illumination system includes a coaxial illumination unit that generates coaxial light that passes through the photographic lens in the facing direction from the image side opposite to the object side toward the object side. The first oblique optical system changes the traveling direction of a portion of the on-axis light into the first oblique direction, thereby generating the illumination light directed from the first oblique direction toward the mounting plane. The imaging lens generates the illumination light directed from the facing direction toward the placement plane by emitting light different from the portion of the light in the coaxial light in the facing direction.

3. The inspection device according to claim 1 or 2, wherein: The object plane of the facing optical path is consistent with the object plane of the first inclined optical path. The facing optical path is the optical path of light emitted from the supporting plane toward the facing direction through the shooting lens to reach the shooting element. The first inclined optical path is the optical path of light emitted from the supporting plane toward the first inclined direction through the first inclined optical system and the shooting lens to reach the shooting element.

4. The inspection device according to claim 3, wherein: The inspection device further includes an optical path adjustment component, which is arranged between the mounting plane and the photographic lens in the facing optical path. The optical path adjustment member detours the light traveling from the mounting plane in the facing direction and then emits it in the facing direction toward the photographing lens, thereby aligning the object plane of the facing optical path with the object plane of the first oblique optical path.

5. The inspection device according to claim 3, wherein: The inspection device further includes an optical path adjustment member disposed between the imaging lens and the imaging element in the first oblique optical path. The optical path adjusting member allows light incident from the photographic lens to propagate inside the optical path adjusting member and then be emitted toward the imaging element, thereby aligning the object plane of the first oblique optical path with the object plane of the facing optical path.

6. The inspection device according to any one of claims 3 to 5, wherein: The first pattern irradiation unit and the first tilting optical system are arranged so that a direction in which pattern light incident on the mounting plane from the first cutting direction is regularly reflected on the mounting plane coincides with the first tilting direction.

7. The inspection device according to claim 1, wherein: The inspection device further comprises: a second oblique optical system for guiding light from the mounting plane in a second oblique direction oblique with respect to the facing direction to the photographic lens; and The second pattern irradiation unit irradiates the mounting plane with a linear pattern light for measuring the shape of the inspection object mounted on the mounting plane by a light section method from a second cutting direction inclined with respect to the facing direction. With respect to the optical axis of the shooting lens, the first tilted optical system is arranged on one side, the first pattern irradiation unit is arranged on the other side opposite to the one side, the second tilted optical system is arranged on the other side, and the second pattern irradiation unit is arranged on the one side.

8. The inspection device according to claim 7, wherein: The object plane of the facing optical path, the object plane of the first inclined optical path, and the object plane of the second inclined optical path are consistent. The facing optical path is the optical path of light emitted from the supporting plane toward the facing direction via the shooting lens to reach the shooting element. The first inclined optical path is the optical path of light emitted from the supporting plane toward the first inclined direction via the first inclined optical system and the shooting lens to reach the shooting element. The second inclined optical path is the optical path of light emitted from the supporting plane toward the second inclined direction via the second inclined optical system and the shooting lens to reach the shooting element.

9. The inspection device according to claim 8, wherein: The first pattern irradiation unit and the first tilting optical system are arranged so that the direction in which the pattern light incident on the mounting plane from the first cutting direction is regularly reflected on the mounting plane coincides with the first tilting direction. The second pattern irradiation unit and the second oblique optical system are arranged so that a direction in which pattern light incident on the mounting plane from the second cutting direction is regularly reflected on the mounting plane coincides with the second oblique direction.

10. The inspection device according to claim 9, wherein: The angle between the first tilting direction and the mounting plane is different from the angle between the second cutting direction and the mounting plane. An angle between the second inclined direction and the placement plane is different from an angle between the first cutting direction and the placement plane.

11. The inspection device according to claim 1, wherein: The inspection device further includes a control unit that sets a straight-on visual field area and an oblique visual field area for the imaging element. The shooting lens images the light emitted from the mounting plane toward the facing direction onto the facing field of view of the shooting element, and images the light emitted from the mounting plane toward the first oblique direction and guided by the first oblique optical system onto the oblique field of view of the shooting element.

12. The inspection device according to claim 11, wherein: The inspection device further includes a scanning drive unit that moves an inspection head including the imaging element, the imaging lens, the first tilting optical system, the lighting system, and the first pattern irradiation unit relative to the mounting plane in a scanning direction. The control unit obtains a plurality of inclined field of view illumination images by causing the scanning drive unit to relatively move the inspection head in the scanning direction and causing the imaging element to repeatedly perform imaging of images composed of the illumination light imaged in the inclined field of view area, and obtains a two-dimensional image of the inspection object placed on the carrying plane by arranging the plurality of inclined field of view illumination images.

13. The inspection device according to claim 12, wherein: The inspection device further includes an illumination light transmitting filter disposed between the imaging element and the imaging lens so as to at least partially overlap the oblique viewing area. The illumination light transmission filter allows the transmission of light of the wavelength of the illumination light, while limiting the transmission of light of the wavelength of the pattern light. The control unit acquires, as the oblique viewing illumination image, an image formed by light formed on a region of the oblique viewing area that overlaps with the illumination light transmission filter.

14. The inspection device according to claim 13, wherein: The inspection device further includes a pattern light transmitting filter disposed between the imaging element and the imaging lens so as to partially overlap the oblique viewing area and be adjacent to the illumination light transmitting filter. The pattern light transmission filter allows the transmission of light of the wavelength of the pattern light, while limiting the transmission of light of the wavelength of the illumination light. The control unit obtains a plurality of inclined field of view pattern images by causing the scanning drive unit to relatively move the inspection head in the scanning direction and causing the imaging element to repeatedly perform imaging of an image consisting of the pattern light imaged in the inclined field of view area in the area overlapping with the pattern light transmission filter, and obtains a three-dimensional image of the inspection object placed on the carrying plane by arranging the plurality of inclined field of view pattern images.

15. The inspection device according to claim 11, wherein The inspection device further includes a scanning drive unit that moves an inspection head including the imaging element, the imaging lens, the first tilting optical system, the lighting system, and the first pattern irradiation unit relative to the mounting plane in a scanning direction. The control unit obtains a plurality of facing field of view pattern images by causing the scanning drive unit to relatively move the inspection head in the scanning direction and causing the imaging element to repeatedly perform imaging of images composed of the patterned light imaged on the facing field of view area, and obtains a three-dimensional image of the inspection object placed on the carrying plane by arranging the plurality of facing field of view pattern images.

16. The inspection device according to claim 15, wherein: The inspection device further includes a pattern light transmitting filter, the pattern light transmitting filter being arranged between the imaging element and the imaging lens so as to at least partially overlap the directly facing field of view area. The pattern light transmission filter allows the transmission of light of the wavelength of the pattern light, while limiting the transmission of light of the wavelength of the illumination light. The control unit acquires an image formed by light formed on a region of the facing viewing area that overlaps with the pattern light transmission filter as the facing viewing area pattern image.

17. The inspection device according to claim 16, wherein: The inspection device further includes an illumination light transmitting filter, which is arranged between the imaging element and the imaging lens so as to partially overlap the directly facing field of view area and be adjacent to the pattern light transmitting filter. The illumination light transmission filter allows the transmission of light of the wavelength of the illumination light, while limiting the transmission of light of the wavelength of the pattern light. The control unit obtains a plurality of directly facing field of view illumination images by causing the scanning drive unit to relatively move the inspection head in the scanning direction and causing the imaging element to repeatedly perform imaging of images consisting of the illumination light imaged in the directly facing field of view area in the area overlapping with the illumination light transmission filter, and obtains a two-dimensional image of the inspection object placed on the carrying plane by arranging the plurality of directly facing field of view illumination images.

18. The inspection device according to claim 1, wherein: The inspection device further comprises: a scanning drive unit that moves an inspection head including the imaging element, the imaging lens, the first tilting optical system, the illumination system, and the first pattern irradiation unit relative to the mounting plane in a scanning direction; as well as The rotation drive unit rotates the inspection head around a rotation axis parallel to the facing direction.

19. An inspection method for inspecting an object to be inspected based on an image captured by imaging light incident from the object side onto an imaging element of a camera through a photographic lens positioned opposite a mounting plane provided on the object side and on which the object to be inspected is mounted, from a predetermined facing direction, wherein: The inspection method comprises: generating illumination light directed toward the mounting plane; a step of irradiating the mounting plane with linear pattern light for measuring the shape of the inspection object mounted on the mounting plane by a light section method from a first cutting direction inclined with respect to the facing direction; a step of guiding light directed from the mounting plane in a first oblique direction tilted relative to the facing direction to the photographing lens by a first oblique optical system; A step of forming an image of light reflected from the mounting plane in the facing direction onto the imaging element by the imaging lens; and The photographing lens forms an image on the imaging element by reflecting the light from the mounting plane in the first oblique direction and guided by the first oblique optical system.

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