Visual inspection equipment, visual inspection methods and recording media

Abstract

The present application provides a kind of appearance inspection device, appearance inspection method and recording medium capable of carrying out the evaluation of the object with high precision with light transmission.The above-mentioned appearance inspection device is provided with: placing part (10), places lens (L);Illumination part (20) can irradiate multiple shapes of illumination light to placing part (10);Camera part (30) photographs placing part (10);Drive part changes the relative position of placing part (10), illumination part (20) and camera part (30);And processor, changes the relative position and the shape of the above-mentioned illumination light and controls the camera part (30) to photograph lens (L) multiple times, the above-mentioned processor makes camera part (30) photograph lens (L) including the reflected light obtained by reflecting illumination light by lens (L) and lens (L) including the transmitted light obtained by transmitting illumination light through lens (L).

Description

Technical Field

[0001] This invention relates to an appearance inspection device, an appearance inspection method, and a recording medium. Background Technology

[0002] Patent Document 1 discloses an optical inspection method in which an object is illuminated from multiple different illumination directions, and multiple images of the object acquired by a camera mechanism in each of the multiple illumination directions are processed by a control device to determine whether the object has defects.

[0003] Patent Document 2 discloses a workpiece inspection apparatus for inspecting the appearance of a workpiece including a curved surface. This workpiece inspection apparatus comprises: a linear sensor camera having a linear imaging range along an orthogonal direction orthogonal to a predetermined direction of the curved surface; a telecentric lens integrally mounted on the linear sensor camera, which directs light parallel to the optical axis of the linear sensor camera onto the linear sensor camera; a side illumination mechanism that emits light from a side position offset from the front of the imaging range along the predetermined direction of the curved surface; a rotation mechanism that rotates the workpiece relative to the linear sensor camera and the side illumination mechanism along the predetermined direction of the curved surface; and an inspection control mechanism that, while the workpiece is rotated relative to the linear sensor camera and the side illumination mechanism and the side illumination mechanism is emitting light, causes the linear sensor camera to capture images of the imaging range, thereby generating an inspection image under side illumination.

[0004] Patent document 3 discloses a method for identifying defects on the surface of a color filter by using a reflective light source above the surface of the color filter, a reflective optical system of an inspection camera, and a transmission optical system above the surface of the color filter.

[0005] Patent Document 4 discloses a visual inspection device comprising: multiple light sources capable of illuminating at least one of the inner and outer circumferential surfaces of a cylindrical object to be inspected, i.e., the photographed surface; and a camera inspection unit for photographing the object and inspecting its appearance based on an image of the photographed area corresponding to a circumferential portion of the photographed surface. This visual inspection device includes a positioning mechanism comprising: a placement unit for positioning the object at an inspection position; and a rotation unit for rotating the object at the inspection position around the central axis of the cylindrical shape. The light sources comprise: a bar light source having a pair of linear light-emitting portions having an optical axis parallel to and extending parallel to the optical axis of the camera inspection unit; and a coaxial light source having an optical axis identical to the optical axis of the camera inspection unit and located between the pair of light-emitting portions. In the aforementioned positioning mechanism, the optical axis of the aforementioned camera inspection unit is orthogonal to the tangent of the photographed surface of the aforementioned object within the aforementioned camera inspection range, and a pair of light-emitting parts of the aforementioned bar light source position the aforementioned object at a position in the direction of the optical axis of the aforementioned camera inspection unit that does not overlap with the photographed surface within the aforementioned camera inspection range. Furthermore, the aforementioned object is positioned at the aforementioned inspection position by an imaging configuration in which the aforementioned central axis is tilted at a predetermined angle relative to the optical axis of the aforementioned camera inspection unit, and the aforementioned camera inspection unit synchronously photographs the aforementioned object based on the rotation of the aforementioned rotating part.

[0006] Previous technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2015-206701

[0009] Patent Document 2: Japanese Patent Application Publication No. 2019-049478

[0010] Patent Document 3: Japanese Patent Application Publication No. 2011-112431

[0011] Patent Document 4: Japanese Patent Application Publication No. 2019-163953 Summary of the Invention

[0012] The technical problem to be solved by the invention

[0013] Previously, visual inspection was performed on transparent components such as lenses or films. Patent Documents 1 and 3, for example, proposed mechanized methods for visual inspection; however, these methods struggled to detect various defects that might arise in the inspected object. Patent Documents 2 and 4 did not assume the inspection of transparent components.

[0014] The purpose of this invention is to evaluate translucent subjects with high precision.

[0015] means for solving technical problems

[0016] An appearance inspection apparatus according to one aspect of the present invention includes: a holding unit for holding a subject; an illumination unit capable of illuminating the holding unit with illumination light of multiple shapes; an imaging unit for capturing images of the holding unit; a driving unit for changing the relative positions of the holding unit, the illumination unit, and the imaging unit; and a processor for controlling the imaging unit to change the relative positions and the shape of the illumination light and to capture images of the subject multiple times, wherein the processor causes the imaging unit to capture images of the subject including reflected light obtained by the subject reflecting the illumination light and transmitted light obtained by the illumination light passing through the subject.

[0017] An appearance inspection apparatus according to one aspect of the present invention includes: a holding unit for holding a subject; an illumination unit capable of illuminating the holding unit with illumination light of multiple shapes; an imaging unit for capturing images of the holding unit; a driving unit for changing the relative positions of the holding unit, the illumination unit, and the imaging unit; and a processor for controlling the changing of the relative positions and the shape of the illumination light and for causing the imaging unit to capture images of the subject multiple times, wherein the processor changes the positions of both the illumination unit and the imaging unit and causes the imaging unit to capture images of the subject.

[0018] An aspect of the present invention provides an appearance inspection method that uses a holding part for holding a subject, an illumination part capable of irradiating the holding part with illumination light of multiple shapes, an imaging part for photographing the holding part, and a driving part for changing the relative positions of the holding part, the illumination part, and the imaging part to inspect the appearance of the subject. The appearance inspection method includes a control step of changing the relative positions and the shape of the illumination light and controlling the imaging part to photograph the subject multiple times. In the control step, the imaging part photographs the subject containing reflected light obtained by the subject reflecting the illumination light and transmitted light obtained by the illumination light passing through the subject.

[0019] An appearance inspection method according to one aspect of the present invention uses a holding part for holding a subject, an illumination part capable of irradiating the holding part with illumination light of multiple shapes, an imaging part for photographing the holding part, and a driving part for changing the relative positions of the holding part, the illumination part, and the imaging part to detect the appearance of the subject. The appearance inspection method includes a control step of controlling the changing of the relative positions and the shape of the illumination light and causing the imaging part to photograph the subject multiple times. In the control step, the positions of the illumination part and the imaging part are changed and the imaging part is photographed on the subject.

[0020] According to one aspect of the present invention, a recording medium records an appearance inspection program. The appearance inspection program uses a holding part for holding a subject, an illumination part capable of irradiating the holding part with illumination light of multiple shapes, a camera part for photographing the holding part, and a drive part for changing the relative positions of the holding part, the illumination part, and the camera part to inspect the appearance of the subject. The appearance inspection program causes a computer to perform the following steps: a control step, which controls the camera part to change the relative positions and the shape of the illumination light and to photograph the subject multiple times. In the control step, the camera part photographs the subject containing reflected light obtained by the subject reflecting the illumination light and the subject containing transmitted light obtained by the illumination light passing through the subject.

[0021] According to one aspect of the present invention, a recording medium records an appearance inspection program. The appearance inspection program uses a holding part for holding a subject, an illumination part capable of illuminating the holding part with illumination light of multiple shapes, a camera part for photographing the holding part, and a drive part for changing the relative positions of the holding part, the illumination part, and the camera part to inspect the appearance of the subject. The appearance inspection program causes a computer to perform the following steps: a control step, which controls the changing of the relative positions and the shape of the illumination light and causes the camera part to photograph the subject multiple times. In the control step, the positions of the illumination part and the camera part are changed and the camera part is photographed on the subject.

[0022] Invention Effects

[0023] According to the present invention, it is possible to evaluate translucent subjects with high precision. Attached Figure Description

[0024] Figure 1 This is a schematic diagram showing the general structure of an embodiment of the present invention, namely the appearance inspection device 100.

[0025] Figure 2 This is a schematic diagram illustrating an example of the positional relationship between the camera unit 30, the mounting unit 10, and the line light source 22 during transmitted light inspection.

[0026] Figure 3 It means in Figure 2 A schematic diagram showing the range of linear light illumination in lens L under state ST1.

[0027] Figure 4 This is a schematic diagram illustrating an example of the positional relationship between the camera unit 30, the mounting unit 10, and the planar light source 21 during the first reflected light inspection process.

[0028] Figure 5 It means in Figure 4 A schematic diagram showing that, under state ST4, the reflected light from the plane light is incident on the light reflection area of ​​the lens L of the imaging unit 30 in sufficient quantity.

[0029] Figure 6 This is a schematic diagram illustrating an example of the positional relationship between the imaging unit 30, the mounting unit 10, and the planar light source 21 during the first reflected light inspection process when the lens L is a concave lens.

[0030] Figure 7 This is a schematic diagram illustrating an example of the positional relationship between the camera unit 30, the mounting unit 10, and the point light source 23 during the second reflected light inspection process.

[0031] Figure 8 This is a flowchart illustrating the operation of the appearance inspection device 100 when performing transmitted light inspection.

[0032] Figure 9 It means Figure 8 A detailed flowchart of step S5.

[0033] Figure 10 It means Figure 8 A detailed flowchart of step S5.

[0034] Figure 11 This is a flowchart illustrating the operation of the appearance inspection device 100 when performing the first reflected light inspection process. Detailed Implementation

[0035] Figure 1 This is a schematic diagram illustrating the general structure of an embodiment of the present invention, namely, an appearance inspection device 100. Figure 1 The diagram shows direction X, direction Y orthogonal to direction X, and direction Z orthogonal to both directions X and Y. For example, the visual inspection device 100 is configured such that direction Z aligns with the vertical direction and the direction opposite to it.

[0036] The visual inspection device 100 includes a base 11 fixed at a predetermined position in the Z direction. A through hole extending along the Z direction is formed in the base 11, and a generally cylindrical mounting portion 10 (an example of a holding portion in this specification) is rotatably supported on the inner wall of this through hole. The mounting portion 10 is a component that mounts a lens L, which is the object to be inspected by the visual inspection device 100. The mounting portion 10 is supported so that it can rotate freely about a rotation axis extending along the Z direction. It is configured such that, with the lens L mounted on the mounting portion 10, the optical axis K of the lens L coincides with the rotation center of the mounting portion 10.

[0037] A rotation mechanism 10A is provided on the base 11 to rotate the mounting portion 10. The mounting portion 10 is configured to rotate around a rotation axis via the rotation mechanism 10A. The rotation angle of the mounting portion 10 is defined as the position of the mounting portion 10.

[0038] The visual inspection device 100 also includes a planar light source 21 constituting a surface light source and a planar light source drive mechanism 21A that moves the planar light source 21 along the X and Z directions and rotates it about an axis Ax1 extending along the Y direction. The planar light source 21 and the planar light source drive mechanism 21A are positioned on the side further in the Z direction than the base 11 (the upper side, the first side in the figure).

[0039] The planar light source 21 irradiates the mounting portion 10 with planar light (area light). The structure of the planar light source 21 is not limited as long as it irradiates area light. For example, the planar light source 21 can be a light source composed of an LED (Light Emitting Diode) and a light guide tube, or a light source composed of a planar organic EL (Electro Luminescence).

[0040] Hereinafter, the position of the planar light source 21 in direction X, the position of the planar light source 21 in direction Z, and the rotation angle of the planar light source 21 around axis Ax1 are defined as the position of the planar light source 21.

[0041] The visual inspection device 100 also includes a line light source 22 constituting a line light source and a line light source drive mechanism 22A that moves the line light source 22 along the X and Z directions and rotates it about an axis Ax2 extending along the Y direction. The line light source 22 and the line light source drive mechanism 22A are positioned on the other side (the lower side, the second side in the figure) further in the Z direction than the base 11.

[0042] The line light source 22 irradiates the mounting portion 10 with linear light (linear light) extending in the Y direction. The structure of the line light source 22 is not limited as long as it irradiates linear light. For example, the line light source 22 can be a light source composed of a metal halide lamp and a light guide or a light source composed of an LED and a light guide.

[0043] Hereinafter, the position of the line light source 22 in the X direction, the position of the line light source 22 in the Z direction, and the rotation angle of the line light source 22 around the axis Ax2 are defined as the position of the line light source 22.

[0044] The visual inspection device 100 also includes a camera mounting unit 10 and a camera unit 30 with a lens L mounted on the mounting unit 10, a point light source 23 fixed to the camera unit 30 constituting a point light source, and a camera unit drive mechanism 30A that moves the camera unit 30 along the X and Z directions and rotates it about an axis Ax3 extending along the Y direction. The camera unit 30, the point light source 23, and the camera unit drive mechanism 30A are positioned on the side further in the Z direction than the base 11 (the upper side, the first side in the figure).

[0045] The camera unit 30 includes an imaging element and a camera optical system, and takes pictures of the lens L placed on the mounting unit 10 through the camera optical system.

[0046] Point light source 23 irradiates the mounting portion 10 with point-shaped light (point light). The structure of point light source 23 is not limited as long as it irradiates point light. For example, point light source 23 can utilize light sources including lasers or LEDs and illumination optical systems. Point light source 23 is fixed to imaging portion 30 with its optical axis intersecting the optical axis of imaging portion 30.

[0047] The camera unit drive mechanism 30A moves or rotates the camera unit 30, thereby moving or rotating the point light source 23 fixed to the camera unit 30. Therefore, the camera unit drive mechanism 30A can also be described as a point light source drive mechanism that moves the point light source 23 along the X and Z directions and rotates it around the axis Ax3.

[0048] Hereinafter, the position of the camera unit 30 in the X direction, the position of the camera unit 30 in the Z direction, and the combination of the rotation angle of the camera unit 30 around the axis Ax3 are defined as the position of the camera unit 30. Similarly, the position of the point light source 23 is defined as the combination of the position of the point light source 23 in the X direction, the position of the point light source 23 in the Z direction, and the rotation angle of the point light source 23 around the axis Ax3.

[0049] The planar light source 21, the line light source 22, and the point light source 23 constitute an illumination section 20 capable of irradiating the mounting section 10 with light of multiple shapes (a line light of the first shape, a planar light of the second shape, and a point light of the third shape).

[0050] Detailed descriptions will follow, but during the visual inspection of lens L for the prescribed evaluation items, any one of the planar light source 21, line light source 22, and point light source 23 is controlled to illuminate the lens. Hereinafter, the position of the light source among the planar light source 21, line light source 22, and point light source 23 that is controlled to illuminate the mounting portion 10 is defined as the position of the illumination portion 20. Furthermore, in the following description, in addition to the light source controlled to illuminate the mounting portion 10, light may also be illuminated from another light source. For example, during the inspection of line light source 22, planar light source 21 may also be used as auxiliary illumination for determining the position of the outer periphery of the lens.

[0051] The planar light source drive mechanism 21A, the line light source drive mechanism 22A, the camera unit drive mechanism 30A, and the rotation mechanism 10A constitute a drive unit that changes the relative positions of the mounting unit 10, the illumination unit 20, and the camera unit 30. The planar light source drive mechanism 21A, the line light source drive mechanism 22A, and the camera unit drive mechanism 30A constitute a drive mechanism that moves the illumination unit 20 and the camera unit 30 relative to the mounting unit 10.

[0052] The visual inspection device 100 also includes a central control unit 40, a position control unit 41, and a lighting control unit 42 for centralized overall control. The central control unit 40, position control unit 41, and lighting control unit 42 each have a processing unit for performing various processes, as well as a memory including RAM (Random Access Memory) and ROM (Read Only Memory). The hardware structure of the processing unit includes various processors as follows.

[0053] Various processors include general-purpose processors that execute software (programs) to perform various processes, such as CPUs (Central Processing Units), FPGAs (Field Programmable Gate Arrays), and other processors whose circuit structure can be changed after manufacturing, such as Programmable Logic Devices (PLDs) or Application Specific Integrated Circuits (ASICs), which have circuit structures specifically designed to perform specific processes, such as dedicated electrical circuits.

[0054] The processing unit can be composed of one of these various processors, or it can be composed of a combination of two or more processors of the same or different types (e.g., multiple FPGAs or a combination of a CPU and an FPGA). The processing units of the central control unit 40, position control unit 41, and lighting control unit 42 each use one or more of the aforementioned processors to construct their hardware structures. More specifically, the hardware structure of these various processors is an electrical circuit that combines circuit elements such as semiconductor components. The central control unit 40, position control unit 41, and lighting control unit 42 can also be a structure in which the processing unit, RAM, and ROM are integrated.

[0055] The position control unit 41 independently drives the camera drive mechanism 30A, the planar light source drive mechanism 21A, the line light source drive mechanism 22A, and the rotation mechanism 10A according to instructions from the central control unit 40. The position control unit 41 operates the camera drive mechanism 30A to control the position of the camera unit 30 and the point light source 23. The position control unit 41 operates the planar light source drive mechanism 21A to control the position of the planar light source 21. The position control unit 41 operates the line light source drive mechanism 22A to control the position of the line light source 22. The position control unit 41 operates the rotation mechanism 10A to control the position of the mounting unit 10.

[0056] The lighting control unit 42 controls the planar light source 21, the line light source 22, and the point light source 23 individually according to the instructions from the central control unit 40.

[0057] When performing an appearance inspection of the lens L placed on the mounting section 10, the central control unit 40 also performs at least a transmitted light inspection process and a first reflected light inspection process. Depending on the structure of the lens L, the central control unit 40 additionally performs a second reflected light inspection process. The details of each inspection process will be explained below.

[0058] (Transmitted light inspection process)

[0059] The transmitted light inspection process includes the following steps: position control, which controls the position of the line light source 22 and the camera unit 30 to a position determined based on the lens information of the lens L (information related to its shape and curvature, etc.); image control, which enables the line light source 22 and the camera unit 30, whose positions have been determined by the position control, to operate, causing the mounting unit 10 to rotate while the camera unit 30 takes multiple images of the lens L illuminated by the line light source 22; and evaluation processing, which performs an evaluation related to the first evaluation item of the lens L based on the multiple images acquired through the image control.

[0060] The first evaluation item refers to scratches (linear defects), spots (dot-like or circular defects), clouding, and combinations of these defects, i.e., dirt, which are widely known as lens defects. Scratches, spots, clouding, and dirt are the main defects of lenses, but other evaluation items may also be included.

[0061] The evaluation related to the first evaluation item of lens L includes, for example, classifying lens L based on the characteristic quantities (length, width, etc.) of scratch areas detected from the camera image, classifying lens L based on the characteristic quantities (size, etc.) of spot areas detected from the camera image, classifying lens L based on the characteristic quantities (area, brightness, etc.) of cloud areas detected from the camera image, and classifying lens L based on the characteristic quantities (size, etc.) of dirt areas detected from the camera image. Classification refers to classifying lens L into grades such as acceptable, unacceptable, and items requiring re-inspection. The size can be calculated, for example, by using (long side + short side) / 2 of the smallest rectangle enclosing the defect. Furthermore, the area of ​​the smallest rectangle enclosing the defect can also be calculated as a size.

[0062] Scratches, spots, cloudiness, and dirt are visually identified by shining light on one side of the optical axis of lens L and observing the transmitted light from the other side of the optical axis of lens L.

[0063] In the image captured by lens L obtained through the aforementioned camera control, areas not illuminated by the line light source 22 will have low and uniform brightness if no scratches, spots, cloudiness, or dirt are present. Conversely, areas with scratches, spots, cloudiness, or dirt will have higher brightness at the defect locations. Therefore, by detecting areas in the image excluding the line light source 22 (areas not illuminated by the line light source 22), the presence or absence of scratches, spots, cloudiness, or dirt can be determined. Following this approach, in the transmitted light inspection process, scratches, spots, cloudiness, or dirt are detected, and an evaluation of the first evaluation item is performed based on the characteristic quantities of each defect.

[0064] Figure 2 This is a schematic diagram illustrating an example of the positional relationship between the camera unit 30, the mounting unit 10, and the line light source 22 during transmitted light inspection processing.

[0065] In the transmitted light inspection process, the centralized control unit 40 presents... Figure 2 The aforementioned position control is performed in state ST1, in which the mounting unit 10 is rotated, and the lens L is photographed when the mounting unit 10 is in each rotated position. Hereinafter, as an example, an example is given where the lens L is photographed once every 12 degrees of rotation of the mounting unit 10, and the mounting unit rotates one full circle. That is, in the above-described camera control, a total of 29 photographs are performed. Furthermore, the shooting interval (angle) and the number of photographs can be arbitrarily set. Also, the mounting unit does not necessarily have to rotate one full circle.

[0066] In the transmitted light inspection process, the centralized control unit 40 further presents... Figure 2The above position control is performed in state ST2. In state ST2, the mounting part 10 is rotated one revolution. When the mounting part 10 is in each rotation position (N times 12 degrees (N = 1 to 29) rotation position), the lens L is photographed.

[0067] The central control unit 40 detects defects in the first evaluation item from 58 video images obtained through 29 shots in state ST1 and 29 shots in state ST2, and grades the lens L based on the detection results.

[0068] Figure 2 The state ST1 shown is that the optical axis of the imaging unit 30 is parallel to the optical axis K of the lens L (in Figure 2 In the example, the positions of the optical axes X and Y are consistent, and the illumination direction of the linear light from the line light source 22 is tilted relative to the optical axis K.

[0069] exist Figure 3 The diagram shows the illumination range AR1 of the linear light illuminating the lens L in state ST1. (See diagram for example.) Figure 3 As shown, in state ST1, linear light is obliquely incident on the central portion (second region) of lens L in direction X. The central portion is a region that includes the optical axis of lens L and has a width in direction X. By rotating the placement unit 10 one revolution in state ST1, the linear light is incident on the entire inspection area (specifically, the region of the effective diameter) of lens L.

[0070] Figure 2 The state ST2 shown is a state relative to state ST1 where only the position of the line light source 22 has changed. Figure 3 The diagram shows the illumination range AR2 of the linear light beam illuminating lens L in state ST2. (See diagram for example.) Figure 3 As shown, in state ST2, linear light obliquely illuminates the region (first region) at one end of the lens L in the direction X. By rotating the mounting unit 10 one revolution in state ST2, the linear light illuminates the entire peripheral region radially outside the inspection area of ​​the lens L.

[0071] exist Figure 3 In the example, the illumination range AR1 extends from one end of the lens L in the direction Y to the other, but is not limited to this. For example, as... Figure 3 In state ST1a, the illumination range AR1 can also be set to the center of the lens L in both the X and Y directions. In this case, by rotating the mounting unit 10 one revolution in state ST1a and one revolution in state ST2, the linear light can illuminate the entire inspection area of ​​the lens L.

[0072] And, as Figure 3In state ST2a, the illumination range AR2 can also be set, for example, between one end and the center of the lens L in the direction X. In this case, by rotating the mounting part 10 one revolution in state ST1 or state ST1a, and then rotating the mounting part 10 one revolution in state ST2a, the linear light can illuminate the entire inspection area of ​​the lens L.

[0073] In state ST1, when the lens L is photographed by the camera unit 30, the position of the line light source 22 is determined in such a way that the line light source 22 does not fall within the illumination range AR1 in the photographed image. This position of the line light source 22 varies depending on the shape of the lens L being inspected and is determined according to the shape of the subject.

[0074] Similarly, in state ST2, when the lens L is photographed by the camera unit 30, the position of the line light source 22 is determined in such a way that the line light source 22 does not fall within the illumination range AR2 in the photographed image. This position of the line light source 22 varies depending on the shape of the lens L being inspected and is determined according to the shape of the subject.

[0075] Furthermore, depending on the structure of lens L, in either state ST1 or state ST2, sometimes a blind spot area that cannot be captured by the camera unit 30 may occur near the periphery of the inspection area of ​​lens L, or an area in the image captured by lens L may occur near the periphery of the inspection area of ​​lens L where the brightness is not sufficiently reduced. In this case, the position of camera unit 30 and the position of line light source 22 are changed so that camera unit 30 can capture the area near the periphery of the inspection area of ​​lens L, and the brightness of the image captured near that periphery is sufficiently reduced.

[0076] like Figure 2 As shown in state ST3, the centralized control unit 40 tilts the optical axis of the imaging unit 30 relative to the optical axis K of the lens L, and controls the position of the imaging unit 30 and the position of the line light source 22 so that the linear light from the line light source 22 illuminates a region (region 3) on one side end of the lens L that is different from that in state ST2. In this state ST3, the centralized control unit 40 rotates the mounting unit 10 one revolution, and captures images of the lens L when the mounting unit 10 is in each rotation position (N times the rotation position of 12 degrees).

[0077] In this case, the central control unit 40 detects defects in the first evaluation item from 87 video images obtained through 29 shots in state ST1, 29 shots in state ST2, and 29 shots in state ST3, and grades the lens L according to the detection results.

[0078] Furthermore, in any of the states ST1, ST2, and ST3, blind spots may sometimes occur that cannot be captured by the camera unit 30. In this case, by flipping the lens inside and outside in the mounting unit 10, the position of the camera unit 30 and the position of the line light source 22 can be controlled in a way that allows the defects existing in the blind spot area to be captured, and additional shots can be taken.

[0079] Figure 2 State ST1 shows that the position of the camera unit 30 is the first camera position and the position of the line light source 22 is the second illumination position. Figure 2 State ST2 shows that the position of the camera unit 30 is the first camera position and the position of the line light source 22 is the first illumination position. Figure 2 Status ST3 indicates that the position of camera unit 30 is the second camera position.

[0080] (First reflected light inspection and processing)

[0081] The first reflected light inspection process includes the following processes: position control, which controls the position of the planar light source 21 and the position of the camera unit 30 to the position determined according to the lens information of the lens L; image control, which enables the planar light source 21 and the camera unit 30, whose positions have been determined by the position control, to operate, so that the mounting unit 10 rotates while the camera unit 30 takes multiple pictures of the lens L illuminated by the planar light; and evaluation processing, which performs an evaluation related to the second evaluation item of the lens L based on the multiple images acquired by the image control.

[0082] The second evaluation item refers to defects that are widely known as lens defects, such as coating peeling (the detachment of the anti-reflective coating on the outer surface) and discoloration (uneven color of the coating or areas with an appearance different from the normal part), which can be observed through positive reflection light. Coating peeling and discoloration are the main defects of lenses, but other evaluation items may also be included.

[0083] The evaluation related to the second evaluation item of lens L includes, for example, classifying lens L based on the characteristic quantity (size) of the coating peeling area detected from the photographic image, and classifying lens L based on the characteristic quantity (size, color information (RGB, HSV), etc.) of the discoloration area detected from the photographic image. Size, for example, can be calculated by dividing the smallest rectangle enclosing the defect by (long side + short side) / 2. Furthermore, the area of ​​the smallest rectangle enclosing the defect can also be calculated as the size. RGB is an abbreviation for Red, Green, and Blue. HSV is an abbreviation for Hue, Saturation, and Value.

[0084] Coating peeling and discoloration are visually identified by illuminating light from one side of the optical axis of lens L and observing the reflected light from the same side. In the image captured by lens L, the area illuminated by the planar light source 21 is free of brightness unevenness as long as there is no coating peeling in that area. If coating peeling is present in that area, an increase in brightness occurs at the location where it is present. Therefore, by determining the presence or absence of areas with brightness exceeding a threshold in the area including the planar light source 21 in the image captured by the image, the presence or absence of coating peeling can be determined.

[0085] Furthermore, in the image captured by lens L, the area illuminated by the planar light source 21 will be free of brightness or color unevenness as long as there is no discoloration in that area. If discoloration exists in that area, brightness or color unevenness will occur in the area where it exists. Therefore, in the area including the planar light source 21 in the image captured by the image, the presence or absence of discoloration can be determined by judging the presence or absence of areas with higher brightness or different hues from the surrounding area. In the first reflected light inspection process, based on this approach, coating peeling and discoloration are detected, and an evaluation of the second evaluation item is performed based on the characteristic quantities of each defect.

[0086] Figure 4 This is a schematic diagram illustrating an example of the positional relationship between the camera unit 30, the mounting unit 10, and the planar light source 21 during the first reflected light inspection process.

[0087] In the first reflected light inspection process, the centralized control unit 40 presents... Figure 4 The above position control is performed in state ST4. In state ST4, the mounting part 10 is rotated one revolution. When the mounting part 10 is in each rotation position (N times the rotation position of 12 degrees), the lens L is photographed.

[0088] Moreover, the centralized control unit 40 presented Figure 4 The above position control is performed in state ST5. In state ST5, the mounting part 10 is rotated one revolution. When the mounting part 10 is in each rotation position (N times the rotation position of 12 degrees), the lens L is photographed.

[0089] The central control unit 40 detects defects in the second evaluation item from 58 video images obtained through 29 shots in state ST4 and 29 shots in state ST5, and grades the lens L based on the detection results.

[0090] Figure 4 The state ST4 shown is a state in which the optical axis of the camera unit 30 is tilted relative to the optical axis K of the lens L, and the direction of the vertical extension of the light-emitting surface of the planar light source 21 is tilted relative to the optical axis K.

[0091] exist Figure 5 The diagram (AR3) illustrates the light reflection area of ​​the lens L of the imaging unit 30 in state ST4, where the reflected light from the planar light source 21 is incident in sufficient quantity. In state ST4, there is a sufficient amount of planar light reflected towards the imaging unit 30 at the center of the lens L in both the X and Y directions. By rotating the mounting unit 10 one revolution in state ST4, a sufficient amount of reflected light can be captured by the imaging unit 30 from the portion of the inspection area of ​​the lens L, excluding the radially outer periphery.

[0092] Figure 4 The state ST5 shown is a state in which the positions of the camera unit 30 and the planar light source 21 have changed relative to state ST4. Figure 5 The frame AR4 illustrates the light reflection area of ​​the lens L of the imaging unit 30 in state ST5, where the reflected light from the planar light source 21 is incident in sufficient quantity. In state ST5, there is a light reflection area on one side of the lens L in the direction X, where a sufficient amount of planar light is reflected towards the imaging unit 30. By rotating the mounting unit 10 one revolution in state ST5, a sufficient amount of reflected light can be captured by the imaging unit 30 from the radially outer periphery of the inspection area of ​​the lens L.

[0093] Thus, in the first reflected light inspection process, the positions of the camera unit 30 and the planar light source 21 are determined such that a sufficient amount of reflected light is incident on the entire inspection area of ​​the lens L. This combination of the positions of the camera unit 30 and the planar light source 21 varies depending on the shape of the lens L being inspected and is determined according to the shape of the object being inspected.

[0094] For example, when lens L is a concave lens, in Figure 6 Lens L was used for shooting under states ST6 and ST7. Figure 6 The boxes AR5 and AR6 shown represent the light reflection area of ​​the lens L of the imaging unit 30, where the reflected light from the planar light source 21 is incident in sufficient quantity.

[0095] Furthermore, due to the structure of lens L, sometimes it is insufficient to allow a sufficient amount of reflected light to enter the imaging unit 30 from the entire inspection area of ​​lens L by shooting from only one side along the optical axis. In this case, by flipping the lens L inside out in the mounting unit 10, the position of the imaging unit 30 and the position of the planar light source 21 can be controlled to perform the shooting.

[0096] (Second reflected light inspection and processing)

[0097] The second reflected light inspection process includes the following steps: position control, which controls the positions of the point light source 23 and the camera unit 30 to the positions determined according to the lens information of the lens L; image control, which enables the point light source 23 and the camera unit 30, whose positions have been determined by the position control, to operate, so that the mounting unit 10 rotates while the camera unit 30 takes multiple pictures of the lens L illuminated by the point light; and evaluation processing, which performs an evaluation related to the third evaluation item of the lens L based on the multiple images acquired by the image control.

[0098] The third evaluation item refers to ink defects that occur only in lenses with an inked section. Ink defects refer to a condition where a portion of the inked section is thin or peeling off.

[0099] The evaluation related to the third evaluation item of lens L refers to classifying lens L based on the characteristic quantity (length or area) of the ink-poor area detected from the photographic image.

[0100] Ink defects are visually identified by illuminating the inked portion of lens L from one side along the optical axis and observing the reflected light from the same side. In the captured image of lens L, the inked portion will appear low-brightness if there are no ink defects. Conversely, if ink defects are present, the brightness will increase at the location of the defect. Therefore, by searching for areas of high brightness within the captured image, including the inked portion, the presence or absence of ink defects can be determined. In the second reflected light inspection process, ink defects are detected based on this approach, and an evaluation of the third evaluation item is performed based on the detection results.

[0101] Figure 7 This is a schematic diagram illustrating an example of the positional relationship between the imaging unit 30, the mounting unit 10, and the point light source 23 during the second reflected light inspection process. Figure 7 The lens L shown has an ink coating section BL.

[0102] In the second reflected light inspection process, the centralized control unit 40 presents... Figure 7 The aforementioned position control is performed in state ST8. In state ST8, the mounting unit 10 rotates one revolution, and the lens L is photographed when the mounting unit 10 is at each rotation position (N times the rotation position of 12 degrees). By rotating the mounting unit 10 one revolution in state ST8, the imaging unit 30 can photograph the reflected light from the entire inked portion BL of the lens L. Furthermore, as described above, 12 degrees is one example, and the shooting interval (angle) and number of shots can be arbitrarily set.

[0103] The central control unit 40 detects defects in the third evaluation item from the ink coating of each of the 29 video images obtained from 29 shots taken under state ST8, and grades the lens L based on the detection results.

[0104] Additionally, there are lens structures where, in state ST8, the entire inked portion BL of the lens L cannot capture reflected point light, or where a portion of the inked portion BL emits light as a whole in state ST8. In such cases, for example, in state ST9, shooting is performed under different conditions where the positions of the imaging unit 30 and the point light source 23 have been changed.

[0105] Thus, by photographing lens L in multiple states, areas with ink defects (areas whose brightness increases due to the illumination of point light) existing in the inked section BL can be detected without omission. In this case, the central control unit 40 detects defects in the inked section BL from each of the 58 photographic images obtained through 29 photographs in state ST8 and 29 photographs in state ST9, and grades lens L according to the detection results.

[0106] Thus, in the second reflected light inspection process, the positions of the imaging unit 30 and the point light source 23 are determined by causing the reflected light from the entire inked portion BL of the lens L to be incident on the imaging unit 30. This combination of the positions of the imaging unit 30 and the point light source 23 varies depending on the shape of the lens L being inspected and is determined according to the shape of the object being inspected.

[0107] Figure 8 This is a flowchart illustrating the operation of the visual inspection device 100 during transmitted light inspection. The following is a description of its operation. Figure 2 The following example illustrates the checks performed under the two conditions shown in states ST1 and ST2.

[0108] The central control unit 40 acquires lens information of lens L and determines state ST1 and state ST2 based on the lens information. Then, the central control unit 40 first controls the position of camera unit 30 and the position of line light source 22 in state ST1 (step S1).

[0109] Next, the central control unit 40 rotates and drives the mounting unit 10. When the rotation angle of the mounting unit 10 increases by 12 degrees, the imaging unit 30 captures the lens L mounted on the mounting unit 10, and the imaging unit 30 acquires and saves the image of the lens L (step S2).

[0110] Next, the central control unit 40 controls the position of the camera unit 30 and the position of the line light source 22 in state ST2 (step S3).

[0111] Next, the central control unit 40 rotates and drives the mounting unit 10. When the rotation angle of the mounting unit 10 increases by 12 degrees, the imaging unit 30 captures the lens L mounted on the mounting unit 10, and the imaging unit 30 acquires and saves the image of the lens L (step S4).

[0112] Next, the central control unit 40 evaluates the lens L based on a total of 58 images, which are the 29 images saved in step S2 and the 29 images saved in step S4, for the four first evaluation items: scratches, spots, cloudiness, and dirt (step S5).

[0113] Figure 9 and Figure 10 It is used for explanation Figure 8 The flowchart details the steps of S5.

[0114] The central control unit 40 sets the reference number "N" to 1 (step S11) and performs defect detection processing on the first predetermined area in the "N"th camera image out of the 29 camera images saved in step S2 (step S12).

[0115] The first predetermined area is the region in the image where the brightness is sufficiently reduced due to the absence of linear light rays, determined based on lens information. The first predetermined area can also be set as a user-specified region.

[0116] Defect detection processing involves binarizing or differentiating the pixel values ​​of a predetermined region, and treating areas with brightness above a detection threshold as defects. The defect detection algorithm is prepared according to each defect category: scratches, spots, cloudiness, and dirt. The central control unit 40 performs four different defect detection processes on a single camera image.

[0117] Next, the central control unit 40 calculates and saves the feature quantity of each defect category detected by the defect detection process in step S12 (step S13).

[0118] Hereinafter, the feature quantity of the scratch defect detected from the Nth image is recorded as the scratch feature quantity Pk(N). The feature quantity of the spot defect detected from the Nth image is recorded as the spot feature quantity Pb(N). The feature quantity of the cloud defect detected from the Nth image is recorded as the cloud feature quantity Pc(N). The feature quantity of the dirt defect detected from the Nth image is recorded as the dirt feature quantity Py(N). The scratch feature quantity Pk(N), spot feature quantity Pb(N), cloud feature quantity Pc(N), and dirt feature quantity Py(N) are collectively referred to as the feature quantity P(N).

[0119] Next, the centralized control unit 40 maintains the maximum value of the feature quantity P(N) as the evaluation data (step S14).

[0120] Specifically, the centralized control unit 40 maintains the maximum value among the scratch feature quantities Pk(N) as scratch evaluation data for evaluating scratch defects. The centralized control unit 40 maintains the maximum value among the spot feature quantities Pb(N) as spot evaluation data for evaluating spot defects. The centralized control unit 40 maintains the maximum value among the cloud spot feature quantities Pc(N) as cloud spot evaluation data for evaluating cloud spot defects. The centralized control unit 40 maintains the maximum value among the dirt feature quantities Py(N) as dirt evaluation data for evaluating dirt defects. Regarding defect categories where no defects were detected, the centralized control unit 40, for example, maintains the lowest value considered to be a feature quantity as evaluation data.

[0121] Next, the central control unit 40 increments the reference number "N" by 1 (step S15) and performs defect detection processing on the first predetermined area in the "N"th camera image out of the 29 camera images saved in step S2 (step S16).

[0122] Next, the central control unit 40 calculates and saves the feature quantity P(N) of the defect for each defect category detected by the defect detection process in step S16 (step S17).

[0123] Next, the central control unit 40 determines, according to each defect category of scratches, spots, cloudiness and dirt, whether the maximum value of the feature quantity P(N) calculated in step S17 is greater than the evaluation data (step S18).

[0124] When the maximum value of the feature quantity P(N) calculated in step S17 is greater than the defect category of the evaluation data, the centralized control unit 40 updates the evaluation data of the defect category according to the maximum value (step S19).

[0125] Specifically, when the maximum value of the scratch feature quantity Pk(N) is greater than the scratch evaluation data, the centralized control unit 40 maintains this maximum value as the latest scratch evaluation data. When the maximum value of the scratch feature quantity Pk(N) is less than or equal to the scratch evaluation data, the centralized control unit 40 does not update the scratch evaluation data.

[0126] When the maximum value of the spot characteristic quantity Pb(N) is greater than the spot evaluation data, the centralized control unit 40 maintains this maximum value as the latest spot evaluation data. When the maximum value of the spot characteristic quantity Pb(N) is less than or equal to the spot evaluation data, the centralized control unit 40 does not update the spot evaluation data.

[0127] When the maximum value in the cloud spot characteristic quantity Pc(N) is greater than the cloud spot evaluation data, the centralized control unit 40 maintains this maximum value as the latest cloud spot evaluation data. When the maximum value in the cloud spot characteristic quantity Pc(N) is less than or equal to the cloud spot evaluation data, the centralized control unit 40 does not update the cloud spot evaluation data.

[0128] When the maximum value of the fouling characteristic quantity Py(N) is greater than the fouling evaluation data, the centralized control unit 40 maintains this maximum value as the latest fouling evaluation data. When the maximum value of the fouling characteristic quantity Py(N) is less than or equal to the fouling evaluation data, the centralized control unit 40 does not update the fouling evaluation data.

[0129] After step S19, when the reference number “N” is less than 29 (step S20: “No”), the central control unit 40 returns the processing to step S15. When the reference number “N” is 29 (step S20: “Yes”), the processing of step S21 is performed.

[0130] In step S21, the centralized control unit 40 sets the reference number "M" to 1. Then, the centralized control unit 40 performs defect detection processing on the second predetermined area in the "M"th image out of the 29 images saved in step S4 (step S22).

[0131] Similar to the first predetermined region, the second predetermined region is a region in the image where the brightness is sufficiently reduced due to the absence of linear light rays, and is predetermined based on lens information. The second predetermined region can also be set as a user-specified region.

[0132] Next, the central control unit 40 calculates and saves the feature quantity of each defect category detected by the defect detection process in step S22 (step S23).

[0133] Hereinafter, the feature quantity of the scratch defect detected from the Mth image is recorded as the scratch feature quantity Pk(M). The feature quantity of the spot defect detected from the Mth image is recorded as the spot feature quantity Pb(M). The feature quantity of the cloud defect detected from the Mth image is recorded as the cloud feature quantity Pc(M). The feature quantity of the dirt defect detected from the Mth image is recorded as the dirt feature quantity Py(M). The scratch feature quantity Pk(M), spot feature quantity Pb(M), cloud feature quantity Pc(M), and dirt feature quantity Py(M) are collectively referred to as the feature quantity P(M).

[0134] Next, the central control unit 40 determines whether the maximum value of the feature quantity P(M) calculated in step S23 is greater than the evaluation data for each defect category, including scratches, spots, cloudiness, and dirt (step S24).

[0135] When the maximum value of the feature quantity P(M) calculated in step S23 is greater than the defect category of the evaluation data, the centralized control unit 40 updates the evaluation data of the defect category according to the maximum value (step S25).

[0136] Specifically, when the maximum value of the scratch feature quantity Pk(M) is greater than the scratch evaluation data, the centralized control unit 40 maintains this maximum value as the latest scratch evaluation data. When the maximum value of the scratch feature quantity Pk(M) is less than or equal to the scratch evaluation data, the centralized control unit 40 does not update the scratch evaluation data.

[0137] When the maximum value of the spot characteristic quantity Pb(M) is greater than the spot evaluation data, the centralized control unit 40 maintains this maximum value as the latest spot evaluation data. When the maximum value of the spot characteristic quantity Pb(M) is less than or equal to the spot evaluation data, the centralized control unit 40 does not update the spot evaluation data.

[0138] When the maximum value in the cloud spot characteristic quantity Pc(M) is greater than the cloud spot evaluation data, the centralized control unit 40 maintains this maximum value as the latest cloud spot evaluation data. When the maximum value in the cloud spot characteristic quantity Pc(M) is less than or equal to the cloud spot evaluation data, the centralized control unit 40 does not update the cloud spot evaluation data.

[0139] When the maximum value of the fouling characteristic quantity Py(M) is greater than the fouling evaluation data, the centralized control unit 40 maintains this maximum value as the latest fouling evaluation data. When the maximum value of the fouling characteristic quantity Py(M) is less than or equal to the fouling evaluation data, the centralized control unit 40 does not update the fouling evaluation data.

[0140] After step S25, when the reference number "M" is less than 29 (step S26: "No"), the centralized control unit 40 increments the reference number "M" by 1 (step S27), and then returns the process to step S22. When the reference number "M" is 29 (step S26: "Yes"), the centralized control unit 40 performs the process of step S28.

[0141] In step S28, the centralized control unit 40 compares the evaluation data for each defect category with a threshold to classify the lens L and saves the results. Specifically, the centralized control unit 40 saves the evaluation level of the lens L with scratch defects, the evaluation level of the lens L with spot defects, the evaluation level of the lens L with cloud defects, and the evaluation level of the lens L related to dirt defects.

[0142] exist Figure 8 Following the action, the central control unit 40 proceeded... Figure 11 The actions shown. Figure 11 This is a flowchart illustrating the operation of the appearance inspection device 100 during the first reflected light inspection process. The following will be explained using... Figure 4 The following examples illustrate the checks performed under the two conditions shown in states ST4 and ST5.

[0143] The central control unit 40 acquires lens information of lens L and determines state ST4 and state ST5 based on the lens information. Then, the central control unit 40 first controls the position of camera unit 30 and the position of planar light source 21 in state ST4 (step S6).

[0144] Next, the central control unit 40 rotates and drives the mounting unit 10. When the rotation angle of the mounting unit 10 increases by 12 degrees, the imaging unit 30 captures the lens L mounted on the mounting unit 10, and the imaging unit 30 acquires and saves the image of the lens L (step S7).

[0145] Next, the central control unit 40 controls the position of the camera unit 30 and the position of the planar light source 21 in state ST5 (step S8).

[0146] Next, the central control unit 40 rotates and drives the mounting unit 10. When the rotation angle of the mounting unit 10 increases by 12 degrees, the imaging unit 30 captures the lens L mounted on the mounting unit 10, and the imaging unit 30 acquires and saves the image of the lens L (step S9).

[0147] Next, the central control unit 40 evaluates the lens L based on a total of 58 images, which are the 29 images saved in step S7 and the 29 images saved in step S9, for the two second evaluation items of coating peeling and discoloration (step S10).

[0148] Processing in step S10 and Figure 9 and Figure 10 The content shown is the same. That is, the central control unit 40 keeps the maximum value among the feature values ​​of coating peeling defects extracted from the 59 camera images as coating peeling evaluation data, and keeps the maximum value among the feature values ​​of discoloration defects extracted from the 59 camera images as discoloration evaluation data.

[0149] Then, the central control unit 40 compares the coating peeling evaluation data with the threshold to determine the evaluation level of the lens L with coating peeling defects, and compares the discoloration evaluation data with the threshold to determine the evaluation level of the lens L with discoloration defects, and saves the determination results.

[0150] exist Figure 8 and Figure 11 After the action is completed, the central control unit 40 determines, for example, the defect category with the worst evaluation level and outputs the evaluation level of that defect category as the final result.

[0151] In addition, the central control unit 40 performs a second reflected light inspection process based on the structure of the lens L, and also evaluates ink defects.

[0152] According to the above-described appearance inspection device 100, defects (scratches, spots, clouding, and dirt) that can be visually identified can be detected with high precision by transmitting light through the lens L and observing the area of ​​the lens L not illuminated by the line light source 22 through the transmitted light inspection process. Furthermore, according to the appearance inspection device 100, defects (coating peeling and discoloration) that can be visually identified can be detected with high precision by reflecting planar light through the lens L and observing the area of ​​the lens L illuminated by that planar light through the first reflected light inspection process. Furthermore, according to the appearance inspection device 100, defects (poor ink quality) that can be visually identified can be detected with high precision by observing the reflected light when dotted light is irradiated onto the ink-coated portion of the lens L through the second reflected light inspection process.

[0153] Thus, according to the appearance inspection device 100, by taking pictures of the lens L under multiple conditions (e.g., state ST1, state ST2, state ST4, and state ST5) where the relative positions of the mounting section 10, the illumination section 20, and the imaging section 30 are different from the combination of the shape of the light irradiated from the illumination section 20, it is possible to detect with high precision various defects that may occur in the lens L that cannot be detected by taking pictures using only a single shape of illumination light or by taking pictures of only the reflected light structure from the subject.

[0154] Furthermore, in the visual inspection device 100, when evaluating the same type of defect (e.g., scratch defects), although the positions of the illumination unit 20 and the imaging unit 30 are the same, scratch defects are detected from 29 imaging images taken from different rotational positions of the mounting unit 10. Then, the lens L with the scratch defect is evaluated based on the maximum value among the characteristic quantities of all detected scratch defects.

[0155] The scratch defects present in lens L may change depending on the viewing position of the imaging unit 30 and the rotation position of the mounting unit 10. This is because the illumination pattern of the linear light on the scratch defect changes with the rotation position. According to the appearance inspection device 100, lens L is evaluated based on the maximum value of the characteristic quantity of the scratch defect detected from each of the 29 photographic images. Therefore, it is possible to prevent the characteristic quantity of a large scratch from being judged as a small value. As a result, lens L can be evaluated with high accuracy.

[0156] Furthermore, in the visual inspection device 100, in order to detect defects of the same type, images are taken under two different conditions (state ST1 and state ST2 or state ST4 and state ST5) depending on the combination of the positions of the camera unit 30 and the illumination unit 20. Therefore, defects that cannot be detected under only one of the two conditions due to the illumination method can be detected under the other condition. Thus, the accuracy of defect detection can be improved.

[0157] (Modified Example)

[0158] The following describes a modified example of the visual inspection device 100.

[0159] The visual inspection device 100 is designed for an object to be inspected, and is not limited to the lens L. Any object that is translucent can be placed on the mounting section 10 to detect defects. In this case, the optical axis K of the lens L can be replaced with the central axis of the object.

[0160] In the visual inspection device 100, the point light source 23 may not be fixed to the camera unit 30. In this case, a separate mechanism is provided to move the point light source 23 along the X and Z directions and rotate it about an axis extending along the Y direction. Alternatively, by fixing the point light source 23 to the camera unit 30... Figure 1 The structure shown can eliminate the mechanism for moving the point light source 23, thereby enabling the miniaturization and cost reduction of the device.

[0161] In the visual inspection device 100, the point light source 23 can be replaced with a surface light source that illuminates a planar light. By illuminating the inked portion of the lens L with light and capturing the reflected light, ink defects can be detected. Therefore, a surface light source can be used instead of the point light source 23. In this case, during the second reflected light inspection process, the planar light source 21 can be moved to the position of the point light source 23. Thus, the number of light sources included in the illumination unit 20 can be set to two, thereby achieving miniaturization and cost reduction of the device.

[0162] In the visual inspection device 100, by making the camera unit 30, the planar light source 21, and the line light source 22 movable, switching between states ST1, ST2, and ST3, or between states ST4 and ST5, can be achieved. As a variation, multiple camera units 30, planar light sources 21, and line light sources 22 can be fixedly arranged, and one of the multiple camera units 30, one of the multiple line light sources 22, and one of the multiple planar light sources 21 can be selected and operated in any of the states ST1, ST2, ST3, ST4, and ST5. Furthermore, as another variation, in addition to moving the camera unit 30, planar light source 21, and line light source 22, or instead of using them, switching between states ST1, ST2, and ST3, or between states ST4 and ST5, can also be achieved by moving or tilting the mounting unit 10. That is, any structure can be moved as long as the relative positions of the mounting part 10 (lens L), the illumination part 20, and the imaging part 30 can be changed. Furthermore, in the appearance inspection device 100, the mounting part 10 was described as an example of a holding part, but the holding part can be any other structure as long as the above-mentioned inspection can be performed without causing scratches to the lens L. For example, the holding part could also be a structure that holds the lens.

[0163] As described above, at least the following items are described in this specification. Additionally, the components corresponding to the above embodiments are shown in parentheses, but the specification is not limited thereto.

[0164] (1) A visual inspection device comprising:

[0165] The preservation department is responsible for preserving the patient.

[0166] The lighting unit is capable of irradiating the aforementioned holding unit with lighting light of various shapes;

[0167] The camera unit will film the aforementioned holding section;

[0168] The driving unit causes a change in the relative positions of the holding unit, the lighting unit, and the camera unit; and

[0169] The processor controls the changes in the relative positions and the shape of the illumination light, and causes the camera to take multiple pictures of the subject.

[0170] The processor causes the camera unit to capture images of the subject containing reflected light obtained by the subject reflecting the illumination light and transmitted light obtained by the illumination light passing through the subject.

[0171] (2) The appearance inspection device according to (1), wherein,

[0172] The aforementioned drive unit includes a rotation mechanism that rotates the aforementioned holding unit to multiple rotational positions.

[0173] (3) The appearance inspection device according to (1) or (2), wherein,

[0174] The aforementioned drive unit includes a drive mechanism that moves the aforementioned lighting unit and the aforementioned camera unit relative to the aforementioned holding unit.

[0175] (4) The appearance inspection device according to any one of (1) to (3), wherein,

[0176] When the side on which the camera unit is positioned relative to the aforementioned holding part is designated as the first side, and the side opposite to the first side is designated as the second side,

[0177] The processor described above performs the following control:

[0178] While the first-shaped illumination light is irradiated onto the holding portion from the second side, the subject is photographed by the imaging unit; and

[0179] While the subject is being illuminated by a second-shaped light from the first side onto the holding part, the camera unit captures an image of the subject.

[0180] (5) The appearance inspection device according to any one of (1) to (3), wherein,

[0181] The aforementioned shapes of light include linear light.

[0182] When the side on which the camera unit is positioned relative to the aforementioned holding part is designated as the first side, and the side opposite to the first side is designated as the second side,

[0183] The aforementioned linear light irradiates from the second side.

[0184] The transmitted light is the linear light that has transmitted the subject.

[0185] (6) The appearance inspection device according to (5), wherein,

[0186] When the linear light is irradiated, the processor controls the position of the illumination unit to a first irradiation position where the linear light irradiates a first region at the end of the subject and a second irradiation position where the linear light irradiates a second region that is separate from the end of the subject.

[0187] (7) The appearance inspection device according to (6), wherein,

[0188] When the linear light is irradiated, the processor controls the position of the camera unit to at least the first imaging position, which is either a first imaging position where the optical axis of the camera unit is parallel to the central axis of the subject or a second imaging position where the optical axis is tilted relative to the central axis.

[0189] (8) The appearance inspection device according to (7), wherein,

[0190] When the camera unit is located at the first camera position, the processor illuminates the linear light from the first illumination position and causes the camera unit to capture an image of the subject. When the camera unit is located at the first camera position, the processor illuminates the linear light from the second illumination position and causes the camera unit to capture an image of the subject. When the camera unit is located at the second camera position, the processor illuminates the linear light onto a third region at the end of the subject that is different from the first region and causes the camera unit to capture an image of the subject.

[0191] (9) The appearance inspection device according to any one of (1) to (8), wherein,

[0192] The aforementioned shapes of light include planar light.

[0193] The reflected light includes the planar light reflected by the subject.

[0194] (10) The appearance inspection device according to (9), wherein,

[0195] The processor changes the combination of the planar light and the relative position to two or more different positions of the illumination unit and the camera unit, and captures the subject containing the reflected light.

[0196] (11) The appearance inspection device according to any one of (1) to (10), wherein,

[0197] The subject of the above examination is a lens.

[0198] The processor acquires information related to the shape of the lens and changes the position of the illumination unit and the position of the camera unit according to the shape of the lens.

[0199] (12) The appearance inspection device according to any one of (1) to (11), wherein,

[0200] The aforementioned shapes of light include planar light, linear light, and point light.

[0201] The processor controls the position of the illumination part when irradiating the planar light, the position of the illumination part when irradiating the linear light, and the position of the illumination part when irradiating the point light to be at different positions.

[0202] (13) The appearance inspection device according to any one of (1) to (12), wherein,

[0203] The aforementioned lighting unit includes a surface light source that illuminates planar light, a line light source that illuminates linear light, and a point light source that illuminates point light.

[0204] The point light source moves in conjunction with the camera unit, while the area light source and the line light source move independently.

[0205] (14) The appearance inspection device according to any one of (1) to (12), wherein,

[0206] The aforementioned lighting unit includes a surface light source that illuminates planar light, a line light source that illuminates linear light, and a point light source that illuminates point light.

[0207] The aforementioned surface light source, the aforementioned line light source, and the aforementioned point light source move independently.

[0208] (15) The appearance inspection device according to any one of (1) to (14), wherein,

[0209] The aforementioned drive unit includes a rotation mechanism that rotates the aforementioned holding unit.

[0210] The processor, having determined the combination of the shape of the illumination light, the position of the illumination unit, and the position of the camera unit, rotates the holding unit while taking multiple pictures of the subject under test.

[0211] (16) The appearance inspection device according to (15), wherein,

[0212] The processor detects specific areas (defect areas) from multiple camera images acquired from the camera unit according to each of the above combinations of the common shapes of the above illumination light, and evaluates the subject based on the feature quantity of the specific area with the largest feature quantity among the detected specific areas.

[0213] (17) A visual inspection device, comprising:

[0214] The preservation department is responsible for preserving the patient.

[0215] The lighting unit is capable of irradiating the aforementioned holding unit with lighting light of various shapes;

[0216] The camera unit will film the aforementioned holding section;

[0217] The driving unit causes a change in the relative positions of the holding unit, the lighting unit, and the camera unit; and

[0218] The processor controls the changes in the relative positions and the shape of the illumination light, and causes the camera to take multiple pictures of the subject.

[0219] The processor changes the positions of the lighting unit and the camera unit and causes the camera unit to capture images of the subject.

[0220] (18) The appearance inspection device according to (17), wherein,

[0221] When the side on which the camera unit is disposed relative to the holding part is designated as the first side, and the side opposite to the first side is designated as the second side, the processor controls the imaging of the subject by the camera unit when the holding part is illuminated by illumination light of the first shape from the second side, and controls the imaging of the subject by the camera unit when the holding part is illuminated by illumination light of the second shape from the first side.

[0222] (19) A method for visual inspection, comprising: a holding part for holding a subject, an illumination part capable of irradiating the holding part with illumination light of multiple shapes, an imaging part for capturing images of the holding part, and a driving part for changing the relative positions of the holding part, the illumination part, and the imaging part; the method comprising:

[0223] The control steps involve changing the relative positions and the shape of the illumination light, and controlling the camera unit to take multiple images of the subject.

[0224] In the above control steps, the camera unit captures images of the subject containing reflected light obtained by the subject reflecting the illumination light and transmitted light obtained by the illumination light passing through the subject.

[0225] (20) A method for visual inspection, comprising: a holding part for holding a subject, an illumination part capable of irradiating the holding part with illumination light of multiple shapes, an imaging part for capturing images of the holding part, and a driving part for changing the relative positions of the holding part, the illumination part, and the imaging part; the method comprising:

[0226] The control steps involve changing the relative positions and the shape of the illumination light, and controlling the camera unit to take multiple images of the subject.

[0227] In the above control steps, the positions of the lighting unit and the camera unit are changed and the camera unit is used to capture images of the subject.

[0228] (21) An appearance inspection procedure that uses a holding part for holding a subject, an illumination part capable of irradiating the holding part with illumination light of multiple shapes, an imaging part for photographing the holding part, and a driving part for changing the relative positions of the holding part, the illumination part, and the imaging part to inspect the appearance of the subject, wherein the appearance inspection procedure causes a computer to perform the following steps:

[0229] The control steps involve changing the relative positions and the shape of the illumination light, and controlling the camera unit to take multiple images of the subject.

[0230] In the above control steps, the camera unit captures images of the subject containing reflected light obtained by the subject reflecting the illumination light and transmitted light obtained by the illumination light passing through the subject.

[0231] (22) An appearance inspection procedure that uses a holding part for holding a subject, an illumination part capable of irradiating the holding part with illumination light of multiple shapes, an imaging part for photographing the holding part, and a driving part for changing the relative positions of the holding part, the illumination part, and the imaging part to inspect the appearance of the subject, wherein the appearance inspection procedure causes a computer to perform the following steps:

[0232] The control steps involve changing the relative positions and the shape of the illumination light, and controlling the camera unit to take multiple images of the subject.

[0233] In the above control steps, the positions of the lighting unit and the camera unit are changed and the camera unit is used to capture images of the subject.

[0234] Various embodiments have been described above with reference to the accompanying drawings, but it is self-evident that they are not limited to the examples involved in this invention. Various modifications and alterations will be readily apparent to those skilled in the art within the scope of the claims, and these are naturally understood to fall within the technical scope of this invention. Furthermore, the constituent elements of the above embodiments can be combined without departing from the spirit of the invention.

[0235] Furthermore, this application claims priority based on Japanese Patent Application No. 2020-197622, ​​filed on November 27, 2020, the contents of which are incorporated herein by reference.

[0236] Symbol Explanation

[0237] AR1, AR2 - Illumination range; AR3, AR4, AR5, AR6 - Frame; 10A - Rotation mechanism; 10 - Mounting part; 11 - Base; 20 - Illumination part; 21 - Planar light source; 21A - Planar light source driving mechanism; 22 - Line light source; 22A - Line light source driving mechanism; 23 - Point light source; 30 - Camera part; 30A - Camera part driving mechanism; 40 - Central control part; 41 - Position control part; 42 - Illumination control part; 100 - Appearance inspection device; L - Lens; Ax1, Ax2, Ax3 - Axis; K - Optical axis; BL - Ink coating part.

Claims

1. An appearance inspection apparatus comprising: a holding portion held by a through-hole of a base so as to be rotatable, which holds an object; a rotation mechanism that rotates the holding portion around a rotation axis extending in a direction of the through-hole; an imaging portion disposed at a position on a first side of the holding portion in the direction of the through-hole, which captures the object held by the holding portion; an imaging portion drive mechanism that changes a position of the imaging portion with respect to the base and an imaging direction; a planar light source disposed on the first side, which is capable of irradiating planar light to the object held by the holding portion; a planar light source drive mechanism that changes a position of the planar light source with respect to the base and an irradiation direction with respect to the object held by the holding portion; a linear light source disposed at a position on a second side of the holding portion opposite to the first side, which is capable of irradiating linear light to the object held by the holding portion; a linear light source drive mechanism that changes a position of the linear light source with respect to the base and an irradiation direction with respect to the object held by the holding portion; and a processor that controls driving of the rotation mechanism, the imaging portion drive mechanism, the planar light source drive mechanism, and the linear light source drive mechanism, operation of the planar light source and the linear light source, and operation of the imaging portion, the processor causing the imaging portion to capture the object with respect to reflected light of the planar light reflected by the object and transmitted light of the linear light transmitted through the object in a case where the object held by the holding portion is positioned at a plurality of rotation positions by driving the rotation mechanism. 2.The appearance inspection apparatus according to claim 1, wherein in a case where the linear light is irradiated, the processor drives the linear light source drive mechanism to control the position of the linear light source at a first irradiation position at which the linear light is irradiated to a first region of an end portion of the object and a second irradiation position at which the linear light is irradiated to a second region separate from the end portion of the object. 3.The appearance inspection apparatus according to claim 2, wherein in a case where the linear light is irradiated, the processor controls the position of the imaging portion at at least a first imaging position at which an optical axis of the imaging portion is parallel to a central axis of the object and a second imaging position at which the optical axis is inclined with respect to the central axis. 4.The appearance inspection apparatus according to claim 3, wherein ​ The processor irradiates the linear light from the first irradiation position and causes the imaging section to capture the subject while the imaging section is at the first imaging position, irradiates the linear light from the second irradiation position and causes the imaging section to capture the subject while the imaging section is at the first imaging position, and irradiates the linear light to a third region different from the first region among the end portions of the subject and causes the imaging section to capture the subject while the imaging section is at the second imaging position.

5. The appearance inspection apparatus according to any one of claims 1 to 4, wherein In a case where the planar light is irradiated, the processor drives the planar light source driving mechanism to control the position of the planar light source at a position at which a sufficient amount of planar light is irradiated to a central portion of the subject and a position at which a sufficient amount of planar light is irradiated to one end portion of the subject.

6. The appearance inspection apparatus according to claim 5, wherein In a case where the planar light is irradiated, the processor drives the imaging section driving mechanism to control the position of the imaging section at a position at which a sufficient amount of reflected light is incident on the imaging section from the subject.

7. The appearance inspection apparatus according to any one of claims 1 to 4, wherein The processor causes the imaging section to capture the subject held by the holding section in a case where the subject is at a plurality of rotational positions, the subject including reflected light of the planar light of the planar light source reflected by the subject, and the subject including transmitted light of the linear light of the linear light source transmitted through the subject, in a state where the position of the planar light source, the position of the linear light source, and the position of the imaging section are controlled at specific positions.

8. The appearance inspection apparatus according to claim 7, wherein The processor performs detection of a specific portion from a plurality of captured images of the subject in a case where the subject is at a plurality of rotational positions, which are acquired from the imaging section in a state where the position of the planar light source, the position of the linear light source, and the position of the imaging section are controlled at specific positions, respectively, performs evaluation of the subject on the basis of a feature amount of a specific portion in which the feature amount is largest among the detected specific portions.

9. The appearance inspection apparatus according to any one of claims 1 to 4, wherein The subject is a lens, The processor acquires information related to the shape of the lens, and changes the position of the planar light source, the position of the linear light source, and the position of the imaging section in accordance with the shape of the lens.

10. The appearance inspection apparatus according to any one of claims 1 to 4, wherein The appearance inspection apparatus further has: a point light source disposed on the first side and capable of irradiating point light to the subject held by the holding section; and a point light source driving mechanism that changes the position of the point light source with respect to the base and the irradiation direction with respect to the subject held by the holding section, The processor causes the imaging section to capture the subject in which the point light of the point light source is reflected by the subject, in a state in which the subject held by the holding section is located at a plurality of rotational positions due to driving of the rotation mechanism.

11. The appearance inspection apparatus according to claim 10, wherein The point light source is fixed to the imaging section, and the imaging section driving mechanism functions as the point light source driving mechanism.

12. The appearance inspection apparatus according to claim 10, wherein The processor causes the imaging section to capture the subject in which the point light of the point light source is reflected by the subject, in a state in which the subject held by the holding section is located at a plurality of rotational positions due to driving of the rotation mechanism.

13. The appearance inspection apparatus according to claim 12, wherein The processor performs detection of a specific part from a plurality of captured images of the subject in which the subject is located at a plurality of rotational positions, which are acquired from the imaging section in a state in which the position of the point light source and the position of the imaging section are controlled at specific positions, respectively, and performs evaluation of the subject based on a feature amount of a specific part in which the feature amount is largest among the detected specific parts.

14. An appearance inspection method in which an appearance of a subject is inspected using the following components: a holding section that holds the subject rotatably supported to a through hole of a base; a rotation mechanism that rotates the holding section around a rotation axis extending in a direction of the through hole; an imaging section that is disposed at a position of a first side, which is a side closer to the through hole than the holding section, and captures the subject held by the holding section; an imaging section driving mechanism that changes a position of the imaging section with respect to the base and an imaging direction; a planar light source that is disposed at the first side and is capable of irradiating a planar light to the subject held by the holding section; a planar light source driving mechanism that changes a position of the planar light source with respect to the base and an irradiation direction to the subject held by the holding section; a linear light source that is disposed at a second side, which is a side opposite to the first side, closer to the through hole than the holding section, and is capable of irradiating a linear light to the subject held by the holding section; and a linear light source driving mechanism that changes a position of the linear light source with respect to the base and an irradiation direction to the subject held by the holding section, wherein the appearance inspection method includes: a driving mechanism control step of driving the rotation mechanism, the imaging section driving mechanism, the planar light source driving mechanism, and the linear light source driving mechanism; a light source operation control step of causing the planar light source and the linear light source to operate; and an imaging control step of causing the imaging section to operate. A plurality of rotational position imaging image acquisition steps are performed using the drive mechanism control step, the light source operation control step, and the imaging control step, in which a plurality of imaging images of the subject containing reflected light of the planar light of the planar light source reflected by the subject and a plurality of imaging images of the subject containing transmitted light of the linear light of the linear light source transmitted through the subject are acquired in a state in which the subject held by the holding portion is positioned at a plurality of rotational positions by driving of the rotational mechanism.

15. The appearance inspection method according to claim 14, wherein The plurality of rotational position imaging image acquisition steps are performed in a state in which the position of the planar light source, the position of the linear light source, and the position of the imaging portion are controlled at specific positions.

16. The appearance inspection method according to claim 15, wherein The plurality of rotational position imaging image acquisition steps are performed a plurality of times by controlling the position of the planar light source, the position of the linear light source, and the position of the imaging portion, which are controlled at specific positions, at other specific positions.

17. A recording medium recording an appearance inspection program for inspecting an appearance of a subject using the following components: a holding portion holding the subject rotatably supported to a through hole of a base; a rotational mechanism rotating the holding portion around a rotational axis extending in a direction of the through hole; an imaging portion configured at a position of a first side, which is a side closer to the through hole than the holding portion, to image the subject held by the holding portion; an imaging portion drive mechanism changing a position of the imaging portion with respect to the base and an imaging direction; a planar light source configured at the first side to be able to irradiate planar light to the subject held by the holding portion; a planar light source drive mechanism changing a position of the planar light source with respect to the base and an irradiation direction to the subject held by the holding portion; a linear light source configured at a second side, which is a side opposite to the first side, to be able to irradiate linear light to the subject held by the holding portion; and a linear light source drive mechanism changing a position of the linear light source with respect to the base and an irradiation direction to the subject held by the holding portion, wherein the appearance inspection program causes a computer to execute: a drive mechanism control step of driving the rotational mechanism, the imaging portion drive mechanism, the planar light source drive mechanism, and the linear light source drive mechanism; a light source operation control step of operating the planar light source and the linear light source; and an imaging control step of operating the imaging portion. ​ The appearance inspection program performs a plurality of rotational position imaging image acquisition steps using the drive mechanism control step, the light source operation control step, and the imaging control step, in which a plurality of imaging images of the subject containing reflected light of the planar light of the planar light source reflected by the subject and a plurality of imaging images of the subject containing transmitted light of the linear light of the linear light source transmitted through the subject are acquired while the subject held by the holding portion is positioned at a plurality of rotational positions by driving of the rotational mechanism.

18. The recording medium according to claim 17, wherein The plurality of rotational position imaging image acquisition steps are performed in a state in which the position of the planar light source, the position of the linear light source, and the position of the imaging portion are controlled at specific positions.

19. The recording medium according to claim 18, wherein The plurality of rotational position imaging image acquisition steps are performed a plurality of times with the position of the planar light source, the position of the linear light source, and the position of the imaging portion controlled at other specific positions.

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