Inspection device and inspection method

Abstract

The present invention provides an inspection device that enables accurate measurement of the edge shape of a target portion on the surface of an object being inspected. [Solution] The inspection device 10 used for inspecting a target part M on the surface S of an object O comprises a control unit 17, an imaging unit 14 that images the inspection area A and acquires the image, an illumination unit 15 that irradiates the inspection area A with light from the opposite side of the imaging unit 14 to the target part M, and a drive unit 16 that rotates the respective positions of the imaging unit 14 and the illumination unit 15 with respect to the inspection area A so that the angles of the optical axes of the imaging unit 14 and the illumination unit 15 with respect to the inspection area A change. The control unit 17 acquires a line profile showing the brightness and darkness in the direction intersecting the target part M in the image for each coordinate of the target part M, and rotates the respective positions of the imaging unit 14 and the illumination unit 15 with respect to the drive unit 16, adjusting the respective angles of the imaging unit 14 and the illumination unit 15 within a predetermined range where the rate of change of brightness and darkness in the line profile exceeds a threshold.

Description

Technical Field

[0001] The present disclosure relates to an inspection apparatus and an inspection method.

Background Art

[0002] Conventionally, techniques for inspecting target portions such as uneven shapes on the surface of an inspection target are known. For example, in Patent Document 1, the surface of a test object is imaged by an imaging camera with only the oblique illumination means (oblique illumination) turned on, the presence or absence of defects in the test object is determined, and whether the defect is convex or concave is determined from the relative position of the defect with respect to the shadow formed by the defect by the oblique illumination. A surface inspection method is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional technique described in Patent Document 1, it is determined whether a defect is convex or concave based on the shadow of the test object, and consideration has not been given to measuring the edge shape of the defect of a plate-shaped test object. In the conventional technique, it has not been easy to accurately measure the edge shape of a target portion such as a defect based on the captured image of the shadow.

[0005] In view of such a point, an object of the present disclosure is to enable accurate measurement of the edge shape of a target portion on the surface of an inspection target.

Means for Solving the Problems

[0006] To solve the above-described problems, an inspection apparatus according to a first aspect is an inspection apparatus used for inspecting a target portion on the surface of an inspection target, Control unit and An imaging unit captures an image of the inspection area of ​​the inspection target, including the target part, and acquires the captured image; An illumination unit that irradiates light onto the target area from the opposite side of the imaging unit into the inspection area, A drive unit that rotates the positions of the imaging unit and the illumination unit with respect to the inspection range so that the angle of the optical axis of each of the imaging unit and the illumination unit with respect to the inspection range changes, Equipped with, The control unit acquires a line profile showing the brightness and darkness in the direction intersecting the target area in the captured image for each coordinate of the target area, and rotates the respective positions of the imaging unit and the illumination unit using the drive unit, adjusting the respective angles of the imaging unit and the illumination unit so that the rate of change of brightness and darkness in the line profile exceeds a predetermined range.

[0007] The second method of inspection is: An inspection method used for inspecting a target part of an object to be inspected, The inspection area of ​​the inspection target, including the aforementioned target part, is imaged by the imaging unit, and the image is acquired. The inspection area is illuminated with light from the opposite side of the imaging unit to the target unit by the illumination unit, Rotating the positions of the imaging unit and the illumination unit with respect to the inspection range such that the angle of the optical axis of each of the imaging unit and the illumination unit with respect to the inspection range changes, While acquiring a line profile showing brightness and darkness in the direction intersecting the target area in the captured image for each coordinate of the target area, the positions of the imaging unit and the illumination unit are rotated, and the angles of the imaging unit and the illumination unit are adjusted so that the rate of change in brightness and darkness in the line profile exceeds a predetermined range. Includes. [Effects of the Invention]

[0008] According to an inspection apparatus and inspection method according to one embodiment of the present disclosure, the edge shape of a target portion on the surface of the object to be inspected can be measured with high accuracy. [Brief explanation of the drawing]

[0009] [Figure 1] This diagram illustrates a part of the configuration of an inspection apparatus according to one embodiment of the present disclosure. [Figure 2] This is a block diagram showing an example of the configuration of an inspection device according to one embodiment of the present disclosure. [Figure 3A] Figure 2 is a flowchart showing a first example of the operation of the inspection device. [Figure 3B] Figure 2 is a flowchart showing a second example of the operation of the inspection device. [Figure 3C] Figure 2 is a flowchart showing a third example of the operation of the inspection device. [Figure 4] Figure 1 is a schematic diagram showing an example of the configuration of the object to be inspected. [Figure 5A] This is the first schematic diagram illustrating an example of the operation of the inspection device in the first step of Figure 3A. [Figure 5B] This is a second schematic diagram illustrating an example of the operation of the inspection device in the first step of Figure 3A. [Figure 5C] This is a third schematic diagram illustrating an example of the operation of the inspection device in the first step of Figure 3A. [Figure 5D] This is the fourth schematic diagram illustrating an example of the operation of the inspection device in the first step of Figure 3A. [Figure 5E] This is the fifth schematic diagram illustrating an example of the operation of the inspection device in the first step of Figure 3A. [Figure 6] This is the sixth schematic diagram illustrating an example of the operation of the inspection device in the first step of Figure 3A. [Figure 7A] This is the first schematic diagram illustrating an example of the operation of the inspection device in the second step of Figure 3B. [Figure 7B] This is a second schematic diagram illustrating an example of the operation of the inspection device in the second step of Figure 3B. [Figure 7C] This is a third schematic diagram illustrating an example of the operation of the inspection device in the second step of Figure 3B. [Figure 7D] It is a fourth schematic diagram for explaining an example of the operation of the inspection apparatus in the second step of FIG. 3B. [Figure 7E] It is a fifth schematic diagram for explaining an example of the operation of the inspection apparatus in the second step of FIG. 3B. [Figure 8] It is a sixth schematic diagram for explaining an example of the operation of the inspection apparatus in the second step of FIG. 3B. [Figure 9] It is a schematic diagram corresponding to FIG. 1, showing another example of the configuration of the inspection object. [Figure 10] It is a schematic diagram corresponding to FIG. 4, showing another example of the configuration of the inspection object. [Figure 11A] It is a first schematic diagram for explaining another example of the operation of the inspection apparatus in the first step of FIG. 3A. [Figure 11B] It is a second schematic diagram for explaining another example of the operation of the inspection apparatus in the first step of FIG. 3A. [Figure 11C] It is a third schematic diagram for explaining another example of the operation of the inspection apparatus in the first step of FIG. 3A. [Figure 11D] It is a fourth schematic diagram for explaining another example of the operation of the inspection apparatus in the first step of FIG. 3A. [Figure 11E] It is a fifth schematic diagram for explaining another example of the operation of the inspection apparatus in the first step of FIG. 3A.

Mode for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present disclosure will be mainly described with reference to the accompanying drawings. The following description also applies to the inspection method executed by the inspection apparatus 10 to which the present disclosure is applied.

[0011] FIG. 1 is a configuration diagram illustrating a part of the configuration of an inspection apparatus 10 according to an embodiment of the present disclosure. With reference to FIG. 1, the outline of the configuration and functions of the inspection apparatus 10 according to an embodiment of the present disclosure will be mainly described. The inspection apparatus 10 includes a pair of imaging units 14 and illumination units 15 arranged so as to sandwich an inspection object O.

[0012] The inspection device 10 is used to inspect a target part M on the surface S of the object to be inspected O. The inspection device 10 is used, for example, to accurately measure the edge shape E of the target part M on the surface S of the object to be inspected O and to inspect the quality of the edge shape E. In this disclosure, "object to be inspected O" includes, for example, a plate-shaped member formed of any material such as metal and plastic. "Surface S" is the surface of the object to be inspected O on which the target part M is located.

[0013] In this disclosure, “target portion M” includes, for example, a convex or concave structure formed on the surface S. Target portion M includes, for example, a convex structure that extends linearly and continuously along the x-direction such that the end in the positive z-axis direction in Figure 1 has an edge shape E. The object to be inspected O may have, for example, a pair of ribs R whose height in the z-direction is higher than that of the target portion M, arranged so as to sandwich the target portion M from both sides in the y-axis direction. The ribs R extend along the x-direction so as to be substantially parallel to the target portion M which extends linearly along the x-direction. The target portion M and the pair of ribs R are arranged on the surface S of the object to be inspected O so as to protrude from the surface S toward the positive z-axis direction, spaced apart from each other in the y-direction.

[0014] A pair of imaging units 14 and illumination units 15 of the inspection device 10 are arranged to sandwich a target part M on the surface S of the object to be inspected O. The pair of imaging units 14 and illumination units 15 are arranged to sandwich an inspection range A of the object to be inspected O, including the target part M, along the y-direction. The pair of imaging units 14 and illumination units 15 are arranged on opposite sides of each other in the y-direction with respect to the inspection range A. In this disclosure, "inspection range A" includes, for example, a range of the surface S of the object to be inspected O that is illuminated by light from the illumination unit 15 and an image is acquired by the imaging unit 14. The inspection range A includes, for example, the entire edge shape E of the target part M and at least a portion in the x-direction of a pair of ribs R.

[0015] Figure 2 is a block diagram showing an example of the configuration of an inspection apparatus 10 according to one embodiment of the present disclosure. An example of the configuration and function of the inspection apparatus 10 according to one embodiment of the present disclosure will be mainly described with reference to Figure 2. The inspection apparatus 10 has a pair of imaging units 14 and illumination units 15, as well as a storage unit 11, an input unit 12, an output unit 13, a drive unit 16, and a control unit 17.

[0016] The storage unit 11 includes one or more semiconductor memories, one or more magnetic memories, one or more optical memories, or a combination of at least two of these. Semiconductor memories include RAM (Random Access Memory) and ROM (Read-Only Memory). RAM includes SRAM (Static Random Access Memory) and DRAM (Dynamic Random Access Memory). ROM includes EEPROM (Electrically Erasable Programmable Read-Only Memory). In addition, the storage unit 11 may also include storage modules such as HDD (Hard Disk Drive) and SSD (Solid State Drive).

[0017] The storage unit 11 stores data obtained by the operation of the inspection device 10. The storage unit 11 stores data used in the operation of the inspection device 10. The storage unit 11 stores system programs, application programs, and various data acquired by any means such as communication. The storage unit 11 may function as a main memory module, an auxiliary memory module, or a cache memory. The storage unit 11 is not limited to one built into the inspection device 10, and may include an external memory module connected by a digital input / output port such as USB (Universal Serial Bus).

[0018] The input unit 12 includes one or more input interfaces that detect user input and acquire input information based on user operations. The input interfaces include physical keys, capacitive keys, pointing devices, touchscreens integrated with the display of the output unit 13, imaging modules such as cameras that accept gesture input, and sound sensors such as microphones that accept voice input.

[0019] The input unit 12 accepts operations to input data used for the operation of the inspection device 10. The input unit 12 may be connected to the inspection device 10 as an external input device, rather than being integrated into the inspection device 10. Connection methods include any method such as USB, HDMI® (High-Definition Multimedia Interface), and Bluetooth®.

[0020] The output unit 13 includes one or more output interfaces that output information to the user. The output interfaces include a display that outputs information visually as an image, a speaker that outputs information aurally as sound, and a vibrator that outputs information tactilely as vibration. The display is, for example, an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display.

[0021] The output unit 13 outputs data obtained by the operation of the inspection device 10 in a visual, auditory, or tactile manner. Instead of being integrated into the inspection device 10, the output unit 13 may be connected to the inspection device 10 as an external output device. Connection methods include any method such as USB, HDMI®, and Bluetooth®.

[0022] The imaging unit 14 includes one or more imaging modules that image the inspection area A of the inspection target O, including the target area M, and acquire the image. The imaging modules include, for example, cameras. The imaging unit 14 outputs the image of the inspection area A to the control unit 17.

[0023] The illumination unit 15 includes one or more illumination modules that irradiate the inspection area A with light from the opposite side of the imaging unit 14 relative to the target unit M. The illumination modules include, for example, illumination light sources that illuminate the inspection area A so that the imaging unit 14 can clearly image the inspection area A of the inspection target O. The illumination unit 15 receives control signals from the control unit 17 and irradiates or turns off light onto the inspection area A.

[0024] The drive unit 16 includes one or more drive modules that rotate the respective positions of the imaging unit 14 and the illumination unit 15 relative to the inspection range A such that the angle of the optical axes of the imaging unit 14 and the illumination unit 15 relative to the inspection range A changes. The drive modules include, for example, a rotation mechanism that moves the imaging unit 14 and the illumination unit 15 along the trajectory of a circular arc virtually drawn in the yz plane of Figure 1, centered on the target area M of the inspection range A. The drive unit 16 drives the imaging unit 14 and the illumination unit 15 in response to control signals from the control unit 17.

[0025] The control unit 17 includes one or more processors, one or more dedicated circuits, or a combination thereof. The processors are general-purpose processors such as CPUs (Central Processing Units) and GPUs (Graphics Processing Units), or dedicated processors specialized for specific processing, but are not limited to these. The dedicated circuits include FPGAs (Field-Programmable Gate Arrays) and ASICs (Application Specific Integrated Circuits), etc. The control unit 17 is communicatively connected to each component constituting the inspection device 10 and executes processing related to the operation of the inspection device 10. The control unit 17 controls the operation of the entire inspection device 10.

[0026] The functions of the inspection device 10 are realized by executing a program according to one embodiment on a processor corresponding to the inspection device 10. The functions of the inspection device 10 are realized by software. The program causes the computer to perform the operations of the inspection device 10, thereby causing the computer to function as the inspection device 10. In other words, the computer functions as the inspection device 10 by performing the operations of the inspection device 10 according to the program.

[0027] In one embodiment, the program may be recorded on a computer-readable recording medium. The computer-readable recording medium includes, for example, a non-temporary computer-readable medium. Examples of non-temporary computer-readable media include magnetic recording devices, optical discs, magneto-optical recording media, or semiconductor memory. The program may be distributed, for example, by selling, transferring, or leasing portable recording media such as DVDs (Digital Versatile Discs) and CD-ROMs (Compact Disc Read-Only Memory) on which the program is recorded. The program may also be distributed by storing the program in the storage of an external server and transmitting the program from the external server to another computer. The program may be provided as a program product.

[0028] Some or all of the functions of the inspection device 10 may be implemented by a dedicated circuit corresponding to the control unit 17. In other words, some or all of the functions of the inspection device 10 may be implemented by hardware.

[0029] Figure 3A is a flowchart illustrating a first example of the operation of the inspection device 10 shown in Figure 2. Referring to Figure 3A, we will mainly describe a first example of an inspection method used to inspect a target part M in the object to be inspected O, as performed by the inspection device 10 shown in Figure 2. Figure 3A shows the process flow when the inspection device 10 adjusts the first angle of the imaging unit 14 with respect to the inspection range A as the first step in the inspection of the target part M.

[0030] In step S101, the control unit 17 of the inspection device 10 illuminates the inspection area A of the inspection target O with light from the opposite side of the imaging unit 14 using the illumination unit 15.

[0031] In step S102, the control unit 17 of the inspection device 10 uses the imaging unit 14 to image the inspection area A of the inspection target O, including the target part M, which was illuminated by the light from the illumination unit 15 in step S101, and acquires the image.

[0032] In step S103, the control unit 17 of the inspection device 10 uses the captured image acquired in step S102 to acquire a line profile indicating the brightness and darkness in the direction intersecting with the target part M for each coordinate of the target part M.

[0033] In step S104, the control unit 17 of the inspection device 10 determines whether the rate of change in brightness / darkness in the line profile acquired in step S103 exceeds a threshold. For example, the control unit 17 determines whether the rate of change in brightness / darkness exceeds a first threshold. If the control unit 17 determines that the rate of change in brightness / darkness exceeds the first threshold, it executes the process in step S106. If the control unit 17 determines that the rate of change in brightness / darkness does not exceed the first threshold, it executes the process in step S105.

[0034] In step S105, if the control unit 17 of the inspection device 10 determines in step S104 that the rate of change in brightness does not exceed the first threshold, it rotates the position of the imaging unit 14 with respect to the inspection range A using the drive unit 16 so that the angle of the optical axis of the imaging unit 14 with respect to the inspection range A changes. After that, the control unit 17 repeats the process from step S101.

[0035] In step S106, if the control unit 17 of the inspection device 10 determines in step S104 that the rate of change in brightness exceeds a first threshold, it adjusts the angle of the imaging unit 14 to a predetermined range in which the rate of change in brightness in the line profile acquired in step S103 exceeds the threshold. For example, the control unit 17 adjusts the first angle of the imaging unit 14 to a first predetermined range in which the rate of change in brightness exceeds the first threshold.

[0036] Figure 3B is a flowchart illustrating a second example of the operation of the inspection device 10 in Figure 2. Referring to Figure 3B, a second example of an inspection method used for inspecting a target part M in an object O, as performed by the inspection device 10 in Figure 2, will be mainly described. Figure 3B shows the processing flow when, for example, as a second step following the first step, the inspection device 10 adjusts the second angle of the illumination unit 15 with respect to the inspection range A in the inspection of the target part M. After adjusting the first angle of the imaging unit 14 to a first predetermined range in step S106 of Figure 3A, the control unit 17 of the inspection device 10 adjusts the second angle of the illumination unit 15 to a second predetermined range where the rate of change in brightness exceeds a second threshold greater than the first threshold.

[0037] In step S201, the control unit 17 of the inspection device 10 illuminates the inspection area A of the inspection object O with light from the opposite side of the imaging unit 14 to the target part M of the inspection object O using the illumination unit 15.

[0038] In step S202, the control unit 17 of the inspection device 10 uses the imaging unit 14 to image the inspection area A of the inspection target O, including the target part M, which was illuminated by the light from the illumination unit 15 in step S201, and acquires the image.

[0039] In step S203, the control unit 17 of the inspection device 10 uses the captured image acquired in step S202 to acquire line profiles indicating the brightness and darkness in the direction intersecting with the target part M for each coordinate of the target part M.

[0040] In step S204, the control unit 17 of the inspection device 10 determines whether the rate of change in brightness / darkness in the line profile acquired in step S203 exceeds a threshold. For example, the control unit 17 determines whether the rate of change in brightness / darkness exceeds a second threshold. If the control unit 17 determines that the rate of change in brightness / darkness exceeds the second threshold, it executes the process in step S206. If the control unit 17 determines that the rate of change in brightness / darkness does not exceed the second threshold, it executes the process in step S205.

[0041] In step S205, if the control unit 17 of the inspection device 10 determines in step S204 that the rate of change in brightness does not exceed the second threshold, it rotates the position of the illumination unit 15 with respect to the inspection range A using the drive unit 16 so that the angle of the optical axis of the illumination unit 15 with respect to the inspection range A changes. After that, the control unit 17 repeats the process from step S201.

[0042] In step S206, if the control unit 17 of the inspection device 10 determines in step S204 that the rate of change in brightness exceeds the second threshold, it adjusts the angle of the illumination unit 15 to a predetermined range in which the rate of change in brightness in the line profile acquired in step S203 exceeds the threshold. For example, the control unit 17 adjusts the second angle of the illumination unit 15 to a second predetermined range in which the rate of change in brightness exceeds the second threshold, which is greater than the first threshold.

[0043] In the first and second steps shown in Figures 3A and 3B, respectively, the control unit 17 of the inspection device 10 rotates the positions of the imaging unit 14 and the illumination unit 15 using the drive unit 16 while acquiring a line profile showing the brightness and darkness in the direction intersecting with the target unit M in the captured image for each coordinate of the target unit M. The control unit 17 adjusts the angles of the imaging unit 14 and the illumination unit 15 to a predetermined range in which the rate of change of brightness and darkness in the line profile exceeds a threshold.

[0044] In this disclosure, “threshold” includes, for example, a first threshold for adjusting the first angle of the optical axis of the imaging unit 14 with respect to the inspection range A, and a second threshold greater than the first threshold for adjusting the second angle of the optical axis of the illumination unit 15 with respect to the inspection range A. “Predetermined range” includes, for example, a first predetermined range that includes the first angle of the imaging unit 14 when the rate of change of brightness exceeds the first threshold, and a second predetermined range that includes the second angle of the illumination unit 15 when the rate of change of brightness exceeds the second threshold. “Angle” includes, for example, the first angle of the optical axis of the imaging unit 14 with respect to the inspection range A, and the second angle of the optical axis of the illumination unit 15 with respect to the inspection range A.

[0045] Figure 3C is a flowchart illustrating a third example of the operation of the inspection device 10 in Figure 2. Referring to Figure 3C, a third example of an inspection method used for inspecting a target part M in an object O will be primarily described. Figure 3C shows the process flow when, for example, as a third step following the second step, the inspection device 10 adjusts the state of the illumination unit 15 relative to the inspection range A during the inspection of the target part M. In this disclosure, "state of the illumination unit 15" includes, for example, at least one of the light intensity of the illumination unit 15 and the distance to the target part M.

[0046] In step S301, the control unit 17 of the inspection device 10 illuminates the inspection area A of the inspection object O with light from the opposite side of the imaging unit 14 to the target part M of the inspection object O using the illumination unit 15.

[0047] In step S302, the control unit 17 of the inspection device 10 uses the imaging unit 14 to image the inspection area A of the inspection target O, including the target part M, which was illuminated by the light from the illumination unit 15 in step S301, and acquires the image.

[0048] In step S303, the control unit 17 of the inspection device 10 uses the captured image acquired in step S302 to acquire line profiles indicating the brightness and darkness in the direction intersecting with the target part M for each coordinate of the target part M.

[0049] In step S304, the control unit 17 of the inspection device 10 determines whether the rate of change in brightness in the line profile acquired in step S303 exceeds another threshold that is greater than the threshold. For example, the control unit 17 determines whether the rate of change in brightness exceeds a third threshold that is greater than the second threshold. If the control unit 17 determines that the rate of change in brightness exceeds the third threshold, it executes the process in step S306. If the control unit 17 determines that the rate of change in brightness does not exceed the third threshold, it executes the process in step S305.

[0050] In step S305, if the control unit 17 of the inspection device 10 determines in step S304 that the rate of change in brightness does not exceed the third threshold, it changes the state of the illumination unit 15. After that, the control unit 17 repeats the process from step S301.

[0051] In step S306, if the control unit 17 of the inspection device 10 determines in step S304 that the rate of change in brightness exceeds the third threshold, it adjusts the state of the illumination unit 15 to a third predetermined range in which the rate of change in brightness in the line profile acquired in step S303 exceeds the third threshold.

[0052] In the third step shown in Figure 3C, the control unit 17 of the inspection device 10 acquires a line profile indicating the brightness and darkness in the direction intersecting the target part M in the captured image for each coordinate of the target part M, and adjusts at least one of the light intensity of the illumination unit 15 and the distance to the target part M so that the rate of change of brightness and darkness in the line profile exceeds another threshold that is greater than the threshold. For example, the control unit 17 adjusts the light intensity of the illumination unit 15 to a third predetermined range in which the rate of change of brightness and darkness in the line profile exceeds a third threshold. For example, the control unit 17 adjusts the distance of the illumination unit 15 to the target part M to a third predetermined range in which the rate of change of brightness and darkness in the line profile exceeds a third threshold. In this disclosure, the "third predetermined range" includes, for example, a first range of light intensity of the illumination unit 15 and a second range of distance of the illumination unit 15 to the target part M.

[0053] The control unit 17 of the inspection device 10 may display the captured image on the output unit 13 each time an image is acquired by the imaging unit 14 in each of the first, second, and third steps, or it may display only the final captured image after the adjustments in each step are completed on the output unit 13.

[0054] Figure 4 is a schematic diagram showing an example of the configuration of the inspection target O in Figure 1. The diagram located in the upper left of Figure 4 shows an image of the inspection range A of the inspection target O as viewed from the positive z-axis direction. Each of the target part M and the pair of ribs R included in the inspection range A is visible as a straight line extending in the x-direction when viewed from directly above.

[0055] In Figure 4, the diagram located in the upper right shows an image of the cross-section when the object to be inspected O is cut in the yz plane for each coordinate x1, x2, and x3 of the target part M. In Figure 4, the diagram located in the lower left shows an image of the cross-section when the object to be inspected O is cut in the xz plane for each coordinate y1, y2, and y3 of the inspection range A. For example, each of the pair of ribs R protrudes from the surface S of the object to be inspected O in the positive z-axis direction with a height a within the inspection range A.

[0056] For example, the target part M protrudes from the surface S of the object O to be inspected in the positive z-axis direction with a height h(x) within the inspection range A. The value of height h(x) changes depending on the x-coordinate. That is, the target part M changes its height in the z-direction for each x-coordinate according to the edge shape E. For example, height h(x1) is h1. Height h(x2) is h2. Height h(x3) is h3=b. Here, h2

[0057] ​Figure 5A is the first schematic diagram illustrating an example of the operation of the inspection device 10 in the first step of Figure 3A. Figure 5B is the second schematic diagram illustrating an example of the operation of the inspection device 10 in the first step of Figure 3A. Figure 5C is the third schematic diagram illustrating an example of the operation of the inspection device 10 in the first step of Figure 3A. Figure 5D is the fourth schematic diagram illustrating an example of the operation of the inspection device 10 in the first step of Figure 3A. Figure 5E is the fifth schematic diagram illustrating an example of the operation of the inspection device 10 in the first step of Figure 3A. Figures 5A to 5E are schematic diagrams illustrating the flow of the series of operations in the first step shown in the flowchart of Figure 3A.

[0058] In each of Figures 5A to 5E, the upper half is a schematic diagram of the target part M and a pair of ribs R that protrude in the positive z-axis direction within the inspection area A, viewed in a cross-section in the yz plane. In each of Figures 5A to 5E, the schematic diagram of the upper half schematically shows the cross-section in the yz plane for a specific x-coordinate. In addition, the schematic diagram of the upper half schematically shows the arrangement relationship of a pair of imaging units 14 and illumination units 15 with respect to the inspection area A. The schematic diagrams of the upper half of Figures 5A to 5E schematically show the arrangement relationship of a pair of imaging units 14 and illumination units 15 from time t0 to time t4. The schematic diagrams of the upper half of Figures 5A to 5E show how the first angle of the optical axis of the imaging unit 14 with respect to the inspection area A changes between time t0 and time t4.

[0059] In each of Figures 5A to 5E, the lower half is a schematic diagram showing an example of an image captured when the inspection area A is illuminated by the illumination unit 15 and the inspection area A is imaged by the imaging unit 14, in the arrangement of the pair of imaging unit 14 and illumination unit 15 shown in the upper half of the diagram. The schematic diagrams in the lower half of Figures 5A to 5E schematically show an example of an image captured by the imaging unit 14 during the time period from time t0 to time t4.

[0060] When the target part M and a pair of ribs R are illuminated by the illumination unit 15 within the inspection area A, the protruding structure including the target part M and the pair of ribs R creates a shadowed area where the light from the illumination unit 15 is blocked, and an area that is brightly illuminated by the light from the illumination unit 15 without overlapping with the shadow. The schematic diagrams of the lower halves of Figures 5A to 5E schematically show the light and dark gradient in the captured image resulting from these shadowed and brightly illuminated areas. The schematic diagrams of the lower halves of Figures 5A to 5E show how the light and dark gradient in the captured image changes as the first angle of the optical axis of the imaging unit 14 with respect to the inspection area A changes between time t0 and time t4.

[0061] In addition to Figures 5A to 5E, Figures 7A to 7E and 11A to 11E show the brightness gradient in the captured image divided into 10 steps, namely gradients G1, G2, G3, G4, G5, G6, G7, G8, G9, and G10. The closer to gradient G1, the brighter the captured image is due to the light from the illumination unit 15. The closer to gradient G10, the darker the captured image is due to the light from the illumination unit 15 being blocked.

[0062] The schematic diagram in the upper half of Figure 5A schematically shows the arrangement of a pair of imaging units 14 and illumination units 15 at time t0 for any other specific x-coordinates other than x1, x2, and x3. In the initial arrangement at time t0, the angle of both the imaging unit 14 and illumination unit 15 with respect to the inspection range A is 0°.

[0063] In this case, in the image captured as shown in the schematic diagram of the lower half of Figure 5A, the light from the illumination unit 15 is blocked by the rib R, and a shadow is created in most of the central and lower parts in the height direction along the z axis, resulting in a gradient G7. In the image captured, above the gradient G7, a gradient G4 is obtained in the upper part where the light from the illumination unit 15 is not blocked by the rib R or the like and is directly incident on the imaging unit 14, resulting in brightness.

[0064] The schematic diagram in the upper half of Figure 5B schematically shows the arrangement of a pair of imaging units 14 and illumination units 15 at time t1 following time t0, with respect to coordinate x2. In the arrangement at time t1, the first angle of the optical axis of the imaging unit 14 with respect to the inspection range A is θ1. In the arrangement at time t1, the second angle of the optical axis of the illumination unit 15 with respect to the inspection range A remains 0°.

[0065] At this time, as the first angle increases from 0° to θ1, the imaging unit 14 is positioned to look into the inspection area A from slightly above the protruding structure including the target area M and the pair of ribs R. Therefore, in the image captured in the schematic diagram of the lower half of Figure 5B, the area that is brightly illuminated without being in shadow near the illumination unit 15 side with respect to the target area M at height h2 is shown as a gradient G4 in the central part enclosed by a circle.

[0066] The schematic diagram in the upper half of Figure 5C schematically shows the arrangement of a pair of imaging units 14 and illumination units 15 at time t2 following time t1, with respect to coordinate x1. In the arrangement at time t2, the first angle of the optical axis of the imaging unit 14 with respect to the inspection range A is θ2, which is greater than θ1. In the arrangement at time t2, the second angle of the optical axis of the illumination unit 15 with respect to the inspection range A remains 0°.

[0067] At this time, as the first angle increases further from θ1 to θ2, the imaging unit 14 is positioned to look into the inspection area A from above the protruding structure including the target area M and the pair of ribs R. Therefore, in the image shown in the schematic diagram of the lower half of Figure 5C, a brightly lit area without shadowing begins to appear near the illumination unit 15 side of the target area M at height h1, and a gradient G4 begins to appear in the circular frame area.

[0068] The schematic diagram in the upper half of Figure 5D schematically shows the arrangement of a pair of imaging units 14 and illumination units 15 at time t3 following time t2, with respect to coordinate x3. In the arrangement at time t3, the first angle of the optical axis of the imaging unit 14 with respect to the inspection range A is θ3, which is greater than θ2. In the arrangement at time t3, the second angle of the optical axis of the illumination unit 15 with respect to the inspection range A remains 0°.

[0069] At this time, as the first angle increases further from θ2 to θ3, the imaging unit 14 is positioned to look into the inspection area A from even higher up than the target area M and the protruding structure including the pair of ribs R. Therefore, in the image shown in the schematic diagram of the lower half of Figure 5D, a brightly lit area without shadowing begins to appear near the illumination unit 15 side of the target area M at height h3=b, and a gradient G4 begins to appear in the circular frame area.

[0070] The schematic diagram in the upper half of Figure 5E schematically shows the arrangement of a pair of imaging units 14 and illumination units 15 at time t4 following time t3, for any other specific x-coordinates other than x1, x2, and x3. In the arrangement at time t4, the first angle of the optical axis of the imaging unit 14 with respect to the inspection range A is 90°, which is greater than θ3. In the arrangement at time t4, the second angle of the optical axis of the illumination unit 15 with respect to the inspection range A remains 0°.

[0071] At this time, as the first angle further increases from θ3 to 90°, the imaging unit 14 is positioned to look down on the protruding structure, including the target part M and the pair of ribs R, along with the inspection area A from directly above. Therefore, in the image shown in the schematic diagram of the lower half of Figure 5E, the target part M and the pair of ribs R are each shown as straight lines extending in the x direction. Because the entire inspection area A is brightly lit without being in shadow, the entire image is shown with a gradient G4.

[0072] As described above, from Figure 5A to Figure 5E, the control unit 17 of the inspection device 10 rotates the position of the imaging unit 14 relative to the inspection range A using the drive unit 16, and gradually increases the first angle of the imaging unit 14 from 0° to 90°. For example, the control unit 17 moves the imaging unit 14 using the drive unit 16 so that the imaging unit 14 traces a circular arc trajectory centered on the target part M that protrudes in the positive z-axis direction within the inspection range A.

[0073] Figure 6 is a sixth schematic diagram illustrating an example of the operation of the inspection device 10 in the first step of Figure 3A. Figure 6 corresponds to Figures 5A to 5E and is a schematic diagram illustrating the flow of the series of operations in the first step shown in the flowchart of Figure 3A.

[0074] In Figure 6, the time axis t located on the far left shows the times t0, t1, t2, t3, and t4 shown in Figures 5A to 5E, respectively. To the right of the time axis t, the captured images shown in the schematic diagrams of the lower half of Figures 5A to 5E are reproduced, corresponding to the times t0, t1, t2, t3, and t4, respectively. The majority of the right side of Figure 6 shows examples of line profiles indicating brightness and darkness in the y-direction intersecting the target area M, acquired for each x-coordinate of the target area M in the captured image, for each of the times t0, t1, t2, t3, and t4. For example, examples of line profiles acquired for coordinates x1, x2, and x3 are shown for each of the times t0, t1, t2, t3, and t4. A total of 15 examples of line profiles are shown.

[0075] In the graphs showing examples of each line profile, the vertical axis corresponds to the y-coordinate. The horizontal axis corresponds to the luminance value, which indicates the degree of brightness in the captured image. Each graph plots the luminance value, which changes along the y-axis at a specific x-coordinate of the target unit M, for each pixel corresponding to the y-axis, in the captured image acquired using the imaging unit 14 at a predetermined time.

[0076] The control unit 17 of the inspection device 10 may acquire rough shape information of the edge shape E of the target part M in advance by any means. For example, the control unit 17 may acquire an image using a pair of imaging units 14 and illumination units 15 arranged in any arrangement with respect to the inspection range A. The control unit 17 may display the acquired image on the output unit 13 and accept user input via the input unit 12 to set the x coordinate of the line profile indicating the brightness of the image.

[0077] The control unit 17 may predetermine the x-coordinates of the feature points of the edge shape E of the target part M according to the user's settings based on the shape information displayed on the output unit 13. In this disclosure, "feature points" include, for example, extreme values ​​and inflection points. The control unit 17 acquires a line profile showing the brightness and darkness in the y-direction intersecting the target part M in the captured image for each x-coordinate of the target part M. For example, the control unit 17 acquires line profiles at coordinates x1, x2, and x3, which are the x-coordinates of the feature points of the edge shape E.

[0078] The control unit 17 rotates the position of the imaging unit 14 using the drive unit 16 while acquiring a line profile for each x-coordinate of the target unit M. The control unit 17 moves the imaging unit 14 by increasing the first angle from the horizontal direction where the first angle is 0°. The control unit 17 acquires multiple similar line profiles for each of the multiple positions of the imaging unit 14 that have changed over time using the drive unit 16.

[0079] The control unit 17 adjusts the first angle of the imaging unit 14 to a first predetermined range in which the rate of change in brightness and darkness in the line profile exceeds a first threshold. In this disclosure, "rate of change in brightness and darkness" means, for example, the difference in luminance value per unit pixel in the line profile. The control unit 17 calculates, for example, the rate of change in brightness and darkness on the line profile in a predetermined range centered on the y coordinate where the target unit M is located. For each of the multiple positions of the imaging unit 14 that have changed over time by the drive unit 16, the control unit 17 compares the rate of change in brightness and darkness in the entire line profile with the first threshold.

[0080] For example, the control unit 17 determines that, at the position of the imaging unit 14 at time t0, the rate of change in brightness near the y coordinate where the target unit M is located does not exceed the first threshold in the entire line profile. At the position of the imaging unit 14 at time t1, the control unit 17 determines that, in the line profile at coordinate x2, the rate of change in brightness near the y coordinate where the target unit M is located exceeds the first threshold.

[0081] The control unit 17 determines that, at the position of the imaging unit 14 at time t2, the rate of change in brightness near the y coordinate where the target unit M is located in the line profile at coordinate x1 exceeds the first threshold. The control unit 17 determines that, at the position of the imaging unit 14 at time t3, the rate of change in brightness near the y coordinate where the target unit M is located in the line profile at coordinate x3 exceeds the first threshold. The control unit 17 determines that, at the position of the imaging unit 14 at time t4, the rate of change in brightness near the y coordinate where the target unit M is located in all line profiles does not exceed the first threshold.

[0082] The control unit 17 adjusts the angle to a predetermined range where the rate of change in brightness exceeds a threshold for all coordinates from which a line profile has been acquired. The control unit 17 adjusts the first angle θ of the imaging unit 14 to a first predetermined range where the rate of change in brightness exceeds a first threshold for all coordinates x1, x2, and x3 from which a line profile has been acquired. In the example shown in Figure 6, the first predetermined range is, for example, θ3 ≤ θ < 90°. The first angle θ that satisfies θ3 ≤ θ < 90° is the angle at which the brightness of the edge shape E of the object to be inspected becomes pronounced.

[0083] Figure 7A is the first schematic diagram illustrating an example of the operation of the inspection device 10 in the second step of Figure 3B. Figure 7B is the second schematic diagram illustrating an example of the operation of the inspection device 10 in the second step of Figure 3B. Figure 7C is the third schematic diagram illustrating an example of the operation of the inspection device 10 in the second step of Figure 3B. Figure 7D is the fourth schematic diagram illustrating an example of the operation of the inspection device 10 in the second step of Figure 3B. Figure 7E is the fifth schematic diagram illustrating an example of the operation of the inspection device 10 in the second step of Figure 3B.

[0084] Figures 7A to 7E are schematic diagrams illustrating the sequence of operations in the second step shown in the flowchart of Figure 3B. The control unit 17 of the inspection device 10, for example, after adjusting the first angle θ as described above, changes the second angle of the illumination unit 15 in the second step to determine optical conditions in which the brightness and darkness of the edge shape E become more pronounced.

[0085] In each of Figures 7A to 7E, the upper half is a schematic diagram of the target part M and a pair of ribs R that protrude in the positive z-axis direction within the inspection area A, viewed in a cross-section in the yz plane. In each of Figures 7A to 7E, the schematic diagram of the upper half schematically shows the cross-section in the yz plane with respect to coordinate x3. In addition, the schematic diagram of the upper half schematically shows the arrangement relationship of a pair of imaging units 14 and illumination units 15 with respect to the inspection area A. The schematic diagrams of the upper half of Figures 7A to 7E schematically show the arrangement relationship of a pair of imaging units 14 and illumination units 15 from time T0 to time T4. The schematic diagrams of the upper half of Figures 7A to 7E show how the second angle of the optical axis of the illumination unit 15 with respect to the inspection area A changes between time T0 and time T4.

[0086] In each of Figures 7A to 7E, the lower half is a schematic diagram showing an example of an image captured when the inspection area A is illuminated by the illumination unit 15 and the inspection area A is imaged by the imaging unit 14, in the arrangement of the pair of imaging unit 14 and illumination unit 15 shown in the upper half of the diagram. The schematic diagrams in the lower half of Figures 7A to 7E schematically show an example of an image captured by the imaging unit 14 during the time period from time T0 to time T4.

[0087] When the target part M and the pair of ribs R are illuminated by the illumination unit 15 within inspection range A, the protruding structure including the target part M and the pair of ribs R creates shadows where the light from the illumination unit 15 is blocked, and areas that are brightly illuminated by the light from the illumination unit 15 without overlapping shadows. The schematic diagrams of the lower halves of Figures 7A to 7E schematically show the light and dark gradient in the captured image resulting from these shadowed and brightly illuminated areas. The schematic diagrams of the lower halves of Figures 7A to 7E show how the light and dark gradient in the captured image changes as the second angle of the optical axis of the illumination unit 15 with respect to inspection range A changes between time T0 and time T4. Note that in the schematic diagrams of the lower halves of Figures 7A to 7D, the shadows in inspection range A (surface S) corresponding to the ribs R located on the upper side are omitted for the sake of simplicity, unlike the shadows of the target part M and the ribs R located on the lower side. The shadow in inspection range A corresponding to the upper rib R is located further back in the y-direction relative to the imaging unit 14, and it is difficult to identify the boundary between the shadow and the rib R; therefore, it is assumed to be included in the upper rib R. For example, in Figure 7D, the shadows in the corresponding inspection range A for the target unit M and the lower rib R are shown by gradient G3, while such a shadow is omitted for the upper rib R.

[0088] The schematic diagram in the upper half of Figure 7A schematically shows the arrangement of a pair of imaging units 14 and illumination units 15 at time T0 with respect to coordinate x3. In the arrangement at time T0, the first angle θ of the optical axis of the imaging unit 14 with respect to the inspection range A maintains the angle adjusted in the first step, satisfying θ3 ≤ θ < 90°. The second angle of the optical axis of the illumination unit 15 with respect to the inspection range A remains 0°.

[0089] In this case, in the image captured in the schematic diagram of the lower half of Figure 7A, gradients G6, G7, and G9 are obtained in the shadowed areas where light from the illumination unit 15 is blocked by the protruding structure including the target part M and a pair of ribs R. On the other hand, in the other areas, a portion of the light from the illumination unit 15 is irradiated onto the inspection area A, resulting in a relatively bright gradient G4.

[0090] The schematic diagram in the upper half of Figure 7B schematically shows the arrangement of a pair of imaging units 14 and illumination units 15 at time T1 following time T0, with respect to coordinate x3. In the arrangement at time T1, the first angle θ of the optical axis of the imaging unit 14 with respect to the inspection range A maintains the angle adjusted in the first step, satisfying θ3 ≤ θ < 90°. In the arrangement at time T1, the second angle of the optical axis of the illumination unit 15 with respect to the inspection range A is φ1.

[0091] At this time, as the second angle increases from 0° to φ1, the illumination unit 15 is positioned to look into the inspection area A from slightly above the protruding structure including the target part M and the pair of ribs R. Therefore, in the captured image shown in the schematic diagram of the lower half of Figure 7B, gradients G6 and G8 are obtained in the shadowed areas where the light from the illumination unit 15 is blocked by the protruding structure including the target part M and the pair of ribs R. On the other hand, in the other areas, the light from the illumination unit 15 is irradiated onto the inspection area A, and a brighter gradient G3 is obtained.

[0092] The schematic diagram in the upper half of Figure 7C schematically shows the arrangement of a pair of imaging units 14 and illumination units 15 at time T2 following time T1, with respect to coordinate x3. In the arrangement at time T2, the first angle θ of the optical axis of the imaging unit 14 with respect to the inspection range A maintains the angle adjusted in the first step, satisfying θ3 ≤ θ < 90°. In the arrangement at time T2, the second angle of the optical axis of the illumination unit 15 with respect to the inspection range A is φ2, which is greater than φ1.

[0093] At this time, as the second angle increases further from φ1 to φ2, the illumination unit 15 is positioned to look into the inspection area A from above the protruding structure including the target part M and the pair of ribs R. Therefore, in the captured image shown in the schematic diagram of the lower half of Figure 7C, gradients G5 and G9 are obtained in the shadowed areas where the light from the illumination unit 15 is blocked by the protruding structure including the target part M and the pair of ribs R. On the other hand, in the other areas, the light from the illumination unit 15 is irradiated onto the inspection area A, and a brighter gradient G2 is obtained.

[0094] The schematic diagram in the upper half of Figure 7D schematically shows the arrangement of a pair of imaging units 14 and illumination units 15 at time T3 following time T2, with respect to coordinate x3. In the arrangement at time T3, the first angle θ of the optical axis of the imaging unit 14 with respect to the inspection range A maintains the angle adjusted in the first step, satisfying θ3 ≤ θ < 90°. In the arrangement at time T3, the second angle of the optical axis of the illumination unit 15 with respect to the inspection range A is φ3, which is greater than φ2.

[0095] At this time, as the second angle increases further from φ2 to φ3, the illumination unit 15 is positioned to look into the inspection area A from even higher up than the protruding structure including the target part M and the pair of ribs R. Therefore, in the captured image shown in the schematic diagram of the lower half of Figure 7D, gradients G3 and G10 are obtained in the shadowed areas where the light from the illumination unit 15 is blocked by the protruding structure including the target part M and the pair of ribs R. On the other hand, in the other areas, the light from the illumination unit 15 is irradiated onto the inspection area A, and an even brighter gradient G1 is obtained.

[0096] The schematic diagram in the upper half of Figure 7E schematically shows the arrangement of a pair of imaging units 14 and illumination units 15 at time T4 following time T3, with respect to coordinate x3. In the arrangement at time T4, the first angle θ of the optical axis of the imaging unit 14 with respect to the inspection range A maintains the angle adjusted in the first step, satisfying θ3 ≤ θ < 90°. In the arrangement at time T4, the second angle of the optical axis of the illumination unit 15 with respect to the inspection range A is 90°, which is greater than φ3.

[0097] At this time, as the second angle increases further from φ3 to 90°, the illumination unit 15 is positioned to look directly above the protruding structure including the target part M and the pair of ribs R, along with the inspection range A. Therefore, in the captured image shown in the schematic diagram of the lower half of Figure 7E, a gradient G10 is obtained in the shadowed area where the light from the illumination unit 15 is blocked by the protruding structure including the target part M and the pair of ribs R. On the other hand, in the other areas, the light from the illumination unit 15 illuminates the inspection range A, and an even brighter gradient G1 is obtained. In addition, at the position of the illumination unit 15 at time T4, the amount of light from the illumination unit 15 on the protruding structure including the target part M and the pair of ribs R becomes too large, causing excessive reflection or scattering of light at the tip of the protruding structure. Therefore, a gradient G1 is also obtained at the tip of the protruding structure.

[0098] As described above, from Figure 7A to Figure 7E, the control unit 17 of the inspection device 10 rotates the position of the illumination unit 15 relative to the inspection range A using the drive unit 16, and gradually increases the second angle of the illumination unit 15 from 0° to 90°. For example, the control unit 17 moves the illumination unit 15 using the drive unit 16 so that the illumination unit 15 traces the trajectory of a circular arc centered on the target part M that protrudes in the positive z-axis direction within the inspection range A.

[0099] Figure 8 is the sixth schematic diagram illustrating an example of the operation of the inspection device 10 in the second step of Figure 3B. In correspondence with Figures 7A to 7E, Figure 8 is a schematic diagram illustrating the sequence of operations in the second step shown in the flowchart of Figure 3B.

[0100] In Figure 8, the time axis t located on the far left shows the times T0, T1, T2, T3, and T4, respectively, as shown in Figures 7A to 7E. To the right of the time axis t, the captured images shown in the schematic diagrams in the lower half of Figures 7A to 7E are reproduced, corresponding to the times T0, T1, T2, T3, and T4. In the majority of the right side of Figure 8, examples of line profiles showing the brightness and darkness in the y-direction intersecting the target area M, acquired for each x-coordinate of the target area M in the captured image, are shown for each of the times T0, T1, T2, T3, and T4. For example, examples of line profiles acquired for coordinates x1, x2, and x3 are shown for each of the times T0, T1, T2, T3, and T4. A total of 15 examples of line profiles are shown.

[0101] In the graphs showing examples of each line profile, the vertical axis corresponds to the y-coordinate. The horizontal axis corresponds to the luminance value, which indicates the degree of brightness in the captured image. Each graph plots the luminance value, which changes along the y-axis at a specific x-coordinate of the target part M, for each pixel corresponding to the y-axis, in the captured image acquired using the imaging unit 14 at a predetermined time. For the purpose of simplifying the illustration, unlike Figure 6, the lower half of the line profile on the vertical axis is omitted in each graph.

[0102] The control unit 17 of the inspection device 10 rotates the position of the illumination unit 15 using the drive unit 16 while acquiring a line profile for each x-coordinate of the target unit M. The control unit 17 moves the illumination unit 15 by increasing the second angle from the horizontal direction where the second angle is 0°. The control unit 17 acquires multiple similar line profiles for each of the multiple positions of the illumination unit 15 that have changed over time by the drive unit 16.

[0103] The control unit 17 adjusts the second angle of the illumination unit 15 to a second predetermined range where the rate of change in brightness in the line profile exceeds a second threshold greater than the first threshold. The control unit 17 calculates the rate of change in brightness on the line profile in a predetermined range centered on the y-coordinate where the target unit M is located. The control unit 17 compares the rate of change in brightness in the entire line profile with the second threshold for each of the multiple positions of the illumination unit 15 that have changed over time by the drive unit 16.

[0104] For example, the control unit 17 determines that, at the position of the illumination unit 15 at time T0, the rate of change in brightness near the y-coordinate where the target unit M is located does not exceed the second threshold in the entire line profile. The control unit 17 also determines that, at the position of the illumination unit 15 at time T1, the rate of change in brightness near the y-coordinate where the target unit M is located does not exceed the second threshold in the entire line profile.

[0105] The control unit 17 determines that, even at the position of the illumination unit 15 at time T2, the rate of change in brightness near the y-coordinate where the target unit M is located does not exceed the second threshold in the entire line profile. The control unit 17 determines that, at the position of the illumination unit 15 at time T3, the rate of change in brightness near the y-coordinate where the target unit M is located exceeds the second threshold in the entire line profile.

[0106] The control unit 17 determines that, at the position of the illumination unit 15 at time T4, the rate of change in brightness near the y-coordinate where the target part M is located does not exceed the second threshold in the entire line profile. At the position of the illumination unit 15 at time T4, the amount of light from the illumination unit 15 to the target part M becomes too large, causing excessive reflection or scattering of light at the target part M. Consequently, the edge shape E of the target part M becomes blurred, and the rate of change in brightness of the line profile also falls below the second threshold. For example, the amount of change in brightness in the line profile near the y-coordinate where the target part M is located is smaller than at time T3. On the other hand, corresponding to the blurring of the edge shape E, the region of pixels where the luminance value is constant on the "bright" side is wider than at time T3.

[0107] The control unit 17 adjusts the angle to a predetermined range where the rate of change in brightness exceeds a threshold for all coordinates from which a line profile has been acquired. The control unit 17 adjusts the second angle φ of the illumination unit 15 to a second predetermined range where the rate of change in brightness exceeds a second threshold for all coordinates x1, x2, and x3 from which a line profile has been acquired. In the example shown in Figure 8, the second predetermined range is, for example, φ3 ≤ φ < 90°. The second angle φ that satisfies φ3 ≤ φ < 90° is the angle at which the brightness of the edge shape E of the object to be inspected becomes even more pronounced.

[0108] Through the first and second steps described above, the control unit 17 of the inspection device 10 determines optical conditions under which the brightness and darkness of the edge shape E become more pronounced. In this disclosure, “optical conditions” include, for example, a first angle θ of the imaging unit 14 and a second angle φ of the illumination unit 15. After adjusting the first angle θ and the second angle φ as described above, the control unit 17 may, in the third step, change the state of the illumination unit 15 to determine optical conditions under which the brightness and darkness of the edge shape E become even more pronounced. In this case, the optical conditions may further include, in addition to the first angle θ of the imaging unit 14 and the second angle φ of the illumination unit 15, at least one of the light intensity of the light from the illumination unit 15 and the distance to the target unit M.

[0109] According to the inspection device 10 of the above embodiment, the edge shape E of the target part M on the surface S of the object to be inspected O can be measured with high accuracy. The inspection device 10 adjusts the angles of the imaging unit 14 and the illumination unit 15 to a predetermined range in which the rate of change of brightness and darkness in the line profile exceeds a threshold. As a result, the inspection device 10 can acquire an image under optical conditions in which the brightness and darkness of the edge shape E of the target part M on the surface S of the object to be inspected becomes prominent. The inspection device 10 can highlight the brightness and darkness of the edge shape E in the image, making it possible to clearly capture the edge shape E. Therefore, the inspection device 10 can accurately measure the edge shape E when inspecting the target part M on the surface S of the object to be inspected O, and can accurately inspect the quality of the edge shape E.

[0110] The inspection device 10 adjusts the first angle of the imaging unit 14 to a first predetermined range where the rate of change in brightness exceeds a first threshold, and then adjusts the second angle of the illumination unit 15 to a second predetermined range where the rate of change in brightness exceeds a second threshold greater than the first threshold. In other words, the inspection device 10 adjusts the first angle of the imaging unit 14 and then adjusts the second angle of the illumination unit 15. This allows the inspection device 10 to roughly adjust the optical conditions by positioning the target part M within the field of view of the imaging unit 14, and then to fine-tune the optical conditions with high precision to the optimal conditions. Therefore, the inspection device 10 can accurately set the optical conditions used for inspecting the target part M on the surface S of the object O to be inspected, and can accurately measure the edge shape E. As a result, the inspection device 10 can accurately inspect the quality of the edge shape E, etc.

[0111] The inspection device 10 adjusts the angle for all coordinates from which a line profile has been acquired to a predetermined range in which the rate of change in brightness exceeds a threshold. As a result, in the first and second steps, the inspection device 10 can accurately set the optimal optical conditions by scanning the imaging unit 14 and the illumination unit 15 once each over the target area M on the surface S of the object to be inspected O. Therefore, the inspection efficiency of the target area M on the surface S of the object to be inspected O is improved.

[0112] The inspection device 10 acquires a line profile for each coordinate and adjusts at least one of the light intensity of the illumination unit 15 and the distance to the target part M so that the rate of change of brightness exceeds one threshold, while simultaneously adjusting the light intensity of the illumination unit 15 to avoid other thresholds that are greater than the other threshold. This allows the inspection device 10 to reduce excessive reflection or scattering of light at the target part M caused by excessive light intensity at the target part M of the illumination unit 15. Therefore, the inspection device 10 can reduce blurring of the edge shape E of the target part M and increase the rate of change of brightness in the line profile.

[0113] As a result, the inspection device 10 can acquire images under optical conditions in which the brightness and darkness of the edge shape E of the target part M on the surface S of the object O to be inspected become more pronounced. The inspection device 10 can more clearly capture the edge shape E by making the brightness and darkness of the edge shape E more prominent in the acquired images. Therefore, the inspection device 10 can more accurately measure the edge shape E when inspecting the target part M on the surface S of the object O to be inspected, and can more accurately inspect the quality of the edge shape E.

[0114] While this disclosure has been described based on the drawings and embodiments, it should be noted that those skilled in the art can make various modifications and alterations based on this disclosure. Therefore, it should be noted that these modifications and alterations are within the scope of this disclosure. For example, the functions included in each configuration or step can be rearranged in a logically consistent manner, and multiple configurations or steps can be combined into one or divided.

[0115] For example, the shape, size, pattern, arrangement, orientation, type, and number of each component described above are not limited to those shown in the above description and drawings. The shape, size, pattern, arrangement, orientation, type, and number of each component may be configured arbitrarily as long as they can achieve their function. Each component of the illustrated inspection device 10 is a functional concept. The specific form of each component is not limited to those shown.

[0116] For example, it is also possible to configure a general-purpose electronic device such as a server, smartphone, or computer to function as the inspection device 10 according to the above embodiment. Specifically, a program describing the processing content that realizes each function of the inspection device 10 according to the embodiment is stored in the memory of the electronic device, and the processor of the electronic device reads and executes the program. Therefore, this disclosure can also be implemented as a program that can be executed by a processor.

[0117] Alternatively, the disclosure may also be implemented as a non-temporary computer-readable medium storing a program executable by one or more processors for causing an inspection device 10 or the like to perform each function according to one embodiment. These are also to be understood as being included within the scope of the disclosure.

[0118] In the above embodiment, the inspection device 10 was described as acquiring line profiles at coordinates x1, x2, and x3, which are the x-coordinates of the feature points of the edge shape E, but it is not limited to this. The inspection device 10 may acquire a number of line profiles other than three depending on the number of feature points of the edge shape E, or it may acquire line profiles at coordinates other than the feature points, in addition to or instead of the feature points.

[0119] In the above embodiment, the inspection device 10 is described as adjusting the first angle of the imaging unit 14 to a first predetermined range where the rate of change in brightness exceeds a first threshold, and then adjusting the second angle of the illumination unit 15 to a second predetermined range where the rate of change in brightness exceeds a second threshold greater than the first threshold, but is not limited to this. The inspection device 10 may perform the second step of adjusting the second angle of the illumination unit 15 before the first step of adjusting the first angle of the imaging unit 14, or the first and second steps may be performed in parallel. The second threshold may be smaller than the first threshold, or it may be the same value as the first threshold.

[0120] In the above embodiment, the inspection device 10 was described as adjusting at least one of the light intensity of the illumination unit 15 and the distance to the target unit M so that the rate of change of brightness exceeds one threshold, while acquiring a line profile for each coordinate. However, it is not limited to this. The inspection device 10 does not have to perform the third step of adjusting the state of the illumination unit 15.

[0121] In the above embodiment, the inspection device 10 was described as performing the third step after the first and second steps, but it is not limited to this. The inspection device 10 may perform the third step at any timing relative to the first and second steps. For example, the inspection device 10 may perform the third step before the first and second steps, or between the first and second steps. For example, the inspection device 10 may perform the first and third steps in parallel, or the second and third steps in parallel, or the first, second, and third steps in parallel.

[0122] Figure 9 is a schematic diagram corresponding to Figure 1, showing another example of the configuration of the object to be inspected O. Figure 10 is a schematic diagram corresponding to Figure 4, showing another example of the configuration of the object to be inspected O. Figure 11A is a first schematic diagram illustrating another example of the operation of the inspection device 10 in the first step of Figure 3A. Figure 11B is a second schematic diagram illustrating another example of the operation of the inspection device 10 in the first step of Figure 3A. Figure 11C is a third schematic diagram illustrating another example of the operation of the inspection device 10 in the first step of Figure 3A. Figure 11D is a fourth schematic diagram illustrating another example of the operation of the inspection device 10 in the first step of Figure 3A. Figure 11E is a fifth schematic diagram illustrating another example of the operation of the inspection device 10 in the first step of Figure 3A. Figures 11A to 11E correspond to Figures 5A to 5E, respectively.

[0123] In the above embodiment, the inspection device 10 was described as adjusting the angle to a predetermined range where the rate of change in brightness exceeds a threshold for all coordinates from which a line profile was acquired, but it is not limited to this. The inspection device 10 may adjust the angle to a predetermined range where the rate of change in brightness exceeds a threshold for only some of the coordinates from which a line profile was acquired.

[0124] For example, consider an object O to be inspected having the configuration shown in FIGS. 9 and 10. At this time, for example, the target part M projects with a height h(x) in the positive z-axis direction from the surface S of the object O in the inspection range A. The value of the height h(x) changes depending on the x coordinate. That is, the target part M changes the height in the z direction for each x coordinate according to the edge shape E. For example, the height h(x1) is h1. The height h(x2) is h2. The height h(x3) is h3 = b. Here, h2≪h1<h3 = b, and b is the maximum value of the height of the target part M in the z direction. Different from the case of the above embodiment, consider a case where the target part M protrudes greatly in the height direction at the coordinates x1 and x3, and the target part M is greatly recessed at the coordinate x2. That is, consider a case where the height h2 is extremely small with respect to the heights h1 and h3.

[0125] In this case, for example, with respect to the central part of the inspection range A surrounded by the circular frame in FIGS. 11B and 11D, when the first angle of the optical axis of the imaging unit 14 with respect to the inspection range A becomes large, in order to image the target part M at the extremely low height h2 from a high angle, the edge shape E is imaged as a straight line. Therefore, it is also assumed that the inspection device 10 cannot accurately measure the edge shape E at the coordinate x2.

[0126] On the other hand, when the imaging unit 14 is arranged at a first angle at which the brightness and darkness of the edge shape E of the flat region in the central part becomes prominent, for the circular frame parts corresponding to the coordinates x1 and x3 in FIGS. 11B, 11C, and 11D, the rate of change of brightness and darkness in the line profile of the edge shape E becomes small. As a result, it is also assumed that the inspection device 10 cannot accurately measure the edge shape E at the coordinates x1 and x3.

[0127] Therefore, when the inspection device 10 determines the x-coordinate of the target part M from which to acquire a line profile, it may set a priority order for multiple x-coordinates. For example, the control unit 17 of the inspection device 10 may use a pair of imaging units 14 and illumination units 15 to adjust the angle with respect to the first priority coordinate among the coordinates and acquire an image with the imaging unit 14, and then adjust the angle with respect to the second priority coordinate among the coordinates and acquire an image with the imaging unit 14. For example, the control unit 17 may use a pair of imaging units 14 and illumination units 15 to adjust the first angle of the imaging unit 14 with respect to the first priority coordinate among the x-coordinates, and then adjust the first angle of the imaging unit 14 with respect to the second priority coordinate among the x-coordinates.

[0128] For example, the first priority coordinate may be at least one of coordinates x1 and x3, and the second priority coordinate may be coordinate x2. However, the inspection device 10 may set three or more priority levels. For example, the first priority coordinate may be coordinate x3, the second priority coordinate may be coordinate x1, and the third priority coordinate may be coordinate x2.

[0129] The control unit 17 of the inspection device 10 may, after adjusting the first angle of the imaging unit 14 in the first priority coordinate system and acquiring an image, return the imaging unit 14 to its initial position, and then adjust the first angle of the imaging unit 14 in the second priority coordinate system and acquire an image again. More specifically, the control unit 17 performs the angle adjustment according to the first and second steps in the first priority coordinate system and acquires an image. The control unit 17 returns the pair of imaging unit 14 and illumination unit 15 to their initial positions. Subsequently, the control unit 17 performs the angle adjustment according to the first and second steps in the second priority coordinate system and acquires an image again.

[0130] As described above, the inspection device 10 can more effectively measure the edge shape E by setting a priority for multiple x coordinates when the rate of change in brightness does not exceed a threshold for all x coordinates from which line profiles have been acquired. For example, if optical conditions including the first and second angles are identified in the first priority coordinate, the rate of change in brightness based on the line profile in the second priority coordinate will be low, and the measurement accuracy of the edge shape E will remain low. In such cases, after the shape measurement of the target part M is completed based on the optical conditions identified in the first priority coordinate, the optical conditions are identified again targeting the second priority coordinate, and the shape measurement of the target part M is performed again. As a result, the inspection device 10 can accurately measure the edge shape E in both the first priority coordinate and the second priority coordinate.

[0131] In the above modified example, the inspection device 10 may, for example, combine a first image acquired with a first priority coordinate as the target and a second image acquired with a second priority coordinate as the target while performing arbitrary image processing to generate an image showing the entire edge shape E of the target part M of the object to be inspected O.

[0132] In the above embodiments and modifications, the inspection device 10 is described as having one set of imaging units 14 and illumination units 15, but it is not limited to this. The inspection device 10 may have multiple sets of imaging units 14 and illumination units 15. Alternatively, the inspection device 10 may have at least one imaging unit 14 and at least one illumination unit 15, and the number of imaging units 14 and the number of illumination units 15 may be different from each other.

[0133] The control unit 17 of the inspection device 10 may use one set of imaging units 14 and illumination units 15 to adjust the angle with respect to the first priority coordinate and acquire an image using the imaging unit 14, and use another set of imaging units 14 and illumination units 15 to adjust the angle with respect to the second priority coordinate and acquire an image using the imaging unit 14. This allows the inspection device 10 to simultaneously determine the optimal optical conditions for different priority coordinates for each priority coordinate. Therefore, the inspection efficiency of the target part M on the surface S of the object O to be inspected is improved.

[0134] Some embodiments of the present disclosure are described below. However, it should be noted that the embodiments of the present disclosure are not limited to these. [Note 1] An inspection device used for inspecting a target part on the surface of an object to be inspected, Control unit and An imaging unit captures an image of the inspection area of ​​the inspection target, including the target part, and acquires the captured image; An illumination unit that irradiates light onto the target area from the opposite side of the imaging unit into the inspection area, A drive unit that rotates the positions of the imaging unit and the illumination unit with respect to the inspection range so that the angle of the optical axis of each of the imaging unit and the illumination unit with respect to the inspection range changes, Equipped with, The control unit acquires a line profile showing the brightness and darkness in the direction intersecting the target area in the captured image for each coordinate of the target area, rotates the respective positions of the imaging unit and the illumination unit using the drive unit, and adjusts the respective angles of the imaging unit and the illumination unit so that the rate of change of brightness and darkness in the line profile exceeds a predetermined range. Inspection device. [Note 2] The inspection device described in Appendix 1, The control unit adjusts the first angle of the imaging unit to a first predetermined range in which the rate of change exceeds a first threshold, and then adjusts the second angle of the illumination unit to a second predetermined range in which the rate of change exceeds a second threshold greater than the first threshold. Inspection device. [Note 3] An inspection device as described in Appendix 1 or 2, The control unit adjusts the angle for all of the coordinates from which the line profile was obtained to a predetermined range in which the rate of change exceeds the threshold. Inspection device. [Note 4] An inspection device as described in Appendix 1 or 2, The control unit adjusts the angle of a portion of the coordinates from which the line profile was obtained to a predetermined range in which the rate of change exceeds the threshold. Inspection device. [Note 5] The inspection device described in Appendix 4, The system comprises a set of imaging units and illumination units, The control unit, using a pair of imaging and illumination units, adjusts the angle with respect to a first priority coordinate among the coordinates to acquire the image using the imaging unit, and then adjusts the angle with respect to a second priority coordinate among the coordinates to acquire the image using the imaging unit. Inspection device. [Note 6] The inspection device described in Appendix 4, The system comprises multiple sets of the imaging unit and the illumination unit, The control unit uses one set of the imaging unit and illumination unit to adjust the angle with respect to the first priority coordinate among the coordinates and acquire the captured image with the imaging unit, and uses the other set of the imaging unit and illumination unit to adjust the angle with respect to the second priority coordinate among the coordinates and acquire the captured image with the imaging unit. Inspection device. [Note 7] An inspection device described in any one of the appendices 1 to 6, The control unit acquires the line profile for each coordinate and adjusts at least one of the light intensity of the illumination unit and the distance to the target unit so that the rate of change exceeds another threshold which is greater than the threshold. Inspection device. [Note 8] An inspection method used for inspecting a target part of an object to be inspected, The inspection area of ​​the inspection target, including the aforementioned target part, is imaged by the imaging unit, and the image is acquired. The inspection area is illuminated with light from the opposite side of the imaging unit to the target unit by the illumination unit, Rotating the positions of the imaging unit and the illumination unit with respect to the inspection range such that the angle of the optical axis of each of the imaging unit and the illumination unit with respect to the inspection range changes, While acquiring a line profile showing brightness and darkness in the direction intersecting the target area in the captured image for each coordinate of the target area, the positions of the imaging unit and the illumination unit are rotated, and the angles of the imaging unit and the illumination unit are adjusted so that the rate of change in brightness and darkness in the line profile exceeds a predetermined range. including, Testing method. [Explanation of Symbols]

[0135] 10 Inspection equipment 11 Storage section 12 Input section 13 Output section 14 Imaging Unit 15 Lighting Section 16 Drive unit 17 Control Unit A. Examination scope E Edge Shape G1, G2, G3, G4, G5, G6, G7, G8, G9, G10 Gradient M Target part O Subject to inspection R Rib S surface

Claims

1. An inspection device used for inspecting a target part on the surface of an object to be inspected, Control unit and An imaging unit captures an image of the inspection area of ​​the inspection target, including the target part, and acquires the captured image; An illumination unit that irradiates light onto the target area from the opposite side of the imaging unit into the inspection area, A drive unit that rotates the positions of the imaging unit and the illumination unit with respect to the inspection range so that the angle of the optical axis of each of the imaging unit and the illumination unit with respect to the inspection range changes, Equipped with, The control unit acquires a line profile showing the brightness and darkness in the direction intersecting the target area in the captured image for each coordinate of the target area, rotates the respective positions of the imaging unit and the illumination unit using the drive unit, and adjusts the respective angles of the imaging unit and the illumination unit so that the rate of change of brightness and darkness in the line profile exceeds a predetermined range. Inspection device.

2. An inspection apparatus according to claim 1, The control unit adjusts the first angle of the imaging unit to a first predetermined range in which the rate of change exceeds a first threshold, and then adjusts the second angle of the illumination unit to a second predetermined range in which the rate of change exceeds a second threshold greater than the first threshold. Inspection device.

3. An inspection apparatus according to claim 1 or 2, The control unit adjusts the angle for all of the coordinates from which the line profile was obtained to a predetermined range in which the rate of change exceeds the threshold. Inspection device.

4. An inspection apparatus according to claim 1 or 2, The control unit adjusts the angle of a portion of the coordinates from which the line profile was obtained to a predetermined range in which the rate of change exceeds the threshold. Inspection device.

5. The inspection apparatus according to claim 4, The system comprises a set of imaging units and illumination units, The control unit, using a pair of imaging and illumination units, adjusts the angle with respect to a first priority coordinate among the coordinates to acquire the image using the imaging unit, and then adjusts the angle with respect to a second priority coordinate among the coordinates to acquire the image using the imaging unit. Inspection device.

6. The inspection apparatus according to claim 4, The system comprises multiple sets of the imaging unit and the illumination unit, The control unit uses one set of the imaging unit and illumination unit to adjust the angle with respect to the first priority coordinate among the coordinates and acquire the captured image with the imaging unit, and uses the other set of the imaging unit and illumination unit to adjust the angle with respect to the second priority coordinate among the coordinates and acquire the captured image with the imaging unit. Inspection device.

7. An inspection apparatus according to claim 1 or 2, The control unit acquires the line profile for each coordinate and adjusts at least one of the light intensity of the illumination unit and the distance to the target unit so that the rate of change exceeds another threshold which is greater than the threshold. Inspection device.

8. An inspection method used for inspecting a target part of an object to be inspected, The inspection area of ​​the inspection target, including the aforementioned target part, is imaged by the imaging unit, and the image is acquired. The inspection area is illuminated with light from the opposite side of the imaging unit to the target unit by the illumination unit, Rotating the positions of the imaging unit and the illumination unit with respect to the inspection range such that the angle of the optical axis of each of the imaging unit and the illumination unit with respect to the inspection range changes, While acquiring a line profile showing brightness and darkness in the direction intersecting the target area in the captured image for each coordinate of the target area, the positions of the imaging unit and the illumination unit are rotated, and the angles of the imaging unit and the illumination unit are adjusted so that the rate of change in brightness and darkness in the line profile exceeds a predetermined range. including, Testing method.

Images