WO2020110711A1 - Inspection system, inspection method, and program - Google Patents

Abstract

This inspection system comprises: an optical system having a variable focal point; an imaging element for generating an image due to reception of light from an object through the optical system; a focus adjustment unit for adjusting a focal point; an inspection unit for inspecting the object on the basis of a first region in an inspection image generated when a focal point is adjusted by the focus adjustment unit, and outputting the inspection results; and an assessment unit for assessing the reliability of focus on a site subject to inspection in the object on the basis of a second region in the inspection image, and outputting the assessment results. Accordingly, the risk of overlooking a defect in an object can be reduced.

Description

Inspection system, inspection method and program

This technology relates to inspection systems, inspection methods, and programs.

Japanese Unexamined Patent Application Publication No. 2018-84701 (Patent Document 1) discloses a focus adjustment device having an autofocus function for searching a focus position of a focus lens based on a contrast evaluation value of a subject image. Further, Patent Document 1 discloses that such a focus adjustment device is applied to an industrial device for inspection.

Japanese Unexamined Patent Publication No. 2018-84701 International Publication No. 2017/056557 JP, 2010-78681, A JP, 10-170817, A

When performing an inspection using the captured image, it is necessary to obtain an image focused on the inspection target part of the object. However, there is a possibility that an image focused on a portion different from the inspection target portion of the target object may be obtained depending on the state of the target object. For example, the focus may be deviated from the inspection target portion of the object due to individual differences in the size of the object. Alternatively, the focus may deviate from the inspection target portion of the object depending on the state of the transfer device that transfers the object. In such a case, since the image is focused on a portion different from the inspection target portion even though the object is defective, the defect at the inspection target portion cannot be recognized and the defect is overlooked.

The present invention has been made in view of the above problems, and an object thereof is to provide an inspection system, an inspection method, and a program that can reduce the risk of overlooking a defect in an object.

According to an example of the present disclosure, an inspection system includes an optical system having a variable focus position, an image sensor that generates an image by receiving light from an object via the optical system, and a focus that adjusts the focus position. An adjustment unit, an inspection unit, and an evaluation unit are provided. The inspection unit inspects the target object based on the first region in the inspection image generated when the focus position is adjusted by the focus adjustment unit, and outputs the inspection result. The evaluation unit evaluates the reliability of focusing of the target object on the inspection target portion based on the second region of the inspection image, and outputs the evaluation result.

According to this disclosure, the reliability of focusing on the inspection target portion is evaluated based on the second area different from the first area. Therefore, for example, even when the contrast of the first region to be inspected is low, the reliability of focusing on the inspection target portion can be evaluated based on the second region different from the first region. Then, based on the evaluation result, it can be recognized that the inspection cannot be performed accurately due to the shift of the focus position. As a result, it is possible to reduce the risk of missing a defective target object as a non-defective product by an inspection based on an image focused on a position different from the inspection target position.

In the above disclosure, the inspection system uses the relative position of the first area and the second area with respect to the inspection image based on the deviation of the position and orientation of the object in the inspection image with respect to the position and orientation of the object in the reference image generated in advance. A correction unit that corrects the position and orientation is further provided.

According to this disclosure, even if the position and orientation of the target object in the inspection image changes, it is possible to suppress deterioration of inspection accuracy and reliability evaluation accuracy.

In the above disclosure, the inspection system determines that the object is a non-defective item when the inspection result satisfies the predetermined first standard and the evaluation result satisfies the predetermined second standard. Is further provided.

According to this disclosure, it is easy to reduce the risk of overlooking a defective target object as a non-defective product by an inspection based on an image focused on a position different from the desired position of the target object.

In the above disclosure, the correction unit obtains the deviation based on the correlation value obtained by the correlation calculation between the reference image and the inspection image. The inspection system, when the inspection result further satisfies a predetermined first criterion, the evaluation result satisfies a predetermined second criterion, and the correlation value satisfies a predetermined third criterion. Further, a determination unit that determines that the object is a non-defective item is further provided.

According to this disclosure, it is possible to further reduce the risk of overlooking a defective target object as a non-defective product, even though the target object cannot be normally imaged.

In the above disclosure, the evaluation result includes the evaluation value calculated based on the focus degree in the second area of the inspection image. Thus, the degree of focus can be easily recognized by checking the evaluation value.

In the above disclosure, the inspection system further includes a search unit that searches for a focus position that is a focus position that focuses on the object. The inspection image is generated when the focus position is adjusted to the in-focus position by the focus adjustment unit. Accordingly, by confirming the evaluation result, it is possible to recognize that the inspection cannot be performed accurately because the search for the in-focus position by the search unit is not performed properly.

According to an example of the present disclosure, an optical system having a variable focus position, an imaging element that generates an image by receiving light from an object via the optical system, and a focus adjustment unit that adjusts the focus position are provided. The inspection method in the inspection system includes a step of inspecting an object based on a first region of an inspection image generated when the focus position is adjusted by the focus adjustment unit, and outputting an inspection result; Based on the second region of the above, the step of evaluating the reliability of focusing of the object with respect to the inspection target portion, and outputting the evaluation result.

According to an example of the present disclosure, a program is a program for causing a computer to execute the above inspection method. These disclosures can also reduce the risk of missing a defect in the object.

According to the present invention, it is possible to reduce the risk of overlooking a defect in an object.

It is a schematic diagram which shows one application example of the inspection system which concerns on embodiment. It is a figure which shows an example of an internal structure of the imaging device with which an inspection system is equipped. It is a schematic diagram for explaining autofocus. It is a figure which shows an example of the lens module whose focal position is variable. It is a figure which shows another example of the lens module whose focal position is variable. 3 is a block diagram showing an example of a hardware configuration of an image processing apparatus according to an embodiment. FIG. It is a figure showing an example of functional composition of an image processing device. It is the figure which showed typically the imaging of the work W by an imaging device. It is a figure which shows an example of the setting screen of an inspection area|region and a reliability evaluation area|region. It is a figure which shows another example of the setting screen of an inspection area and a reliability evaluation area. It is a figure which shows an example of a focus degree waveform. 6 is a flowchart showing an example of the flow of an inspection process of the inspection system according to the embodiment. It is a schematic diagram which shows the inspection system which concerns on the modification 1. It is a figure which shows an example of the setting screen of an inspection area|region, a reliability evaluation area|region, and a model area|region. It is a figure explaining the process of a correction|amendment part. 9 is a flowchart showing the flow of inspection processing of the inspection system according to Modification 1. 13 is a flowchart showing the flow of inspection processing of the inspection system according to Modification 3.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following description, the same parts and components are designated by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

§1 Application Example First, an example of a scene to which the present invention is applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram showing one application example of the inspection system according to the embodiment. FIG. 2 is a diagram illustrating an example of an internal configuration of an image pickup apparatus included in the inspection system.

As shown in FIG. 1, the inspection system 1 according to the present embodiment is realized as, for example, an appearance inspection system. The inspection system 1 images an inspection target portion on an object (work W) placed on the stage 90 in, for example, a production line of an industrial product, and uses the obtained image to inspect the appearance of the work W. I do. In the visual inspection, the work W is inspected for scratches, dirt, presence of foreign matter, dimensions, and the like.

When the visual inspection of the work W placed on the stage 90 is completed, the next work (not shown) is transported onto the stage 90. When capturing the image of the work W, the work W may stand still at a predetermined position on the stage 90 in a predetermined posture. Alternatively, the work W may be imaged while the work W moves on the stage 90.

As shown in FIG. 1, the inspection system 1 includes an imaging device 10 and an image processing device 20 as basic components. In this embodiment, the inspection system 1 further includes a PLC (Programmable Logic Controller) 30, an input device 40, and a display device 50.

The imaging device 10 is connected to the image processing device 20. The imaging device 10 images a subject (workpiece W) existing in the imaging field of view according to a command from the image processing device 20, and generates image data including an image of the workpiece W. The imaging device 10 and the image processing device 20 may be integrated.

As shown in FIG. 2, the imaging device 10 includes an illumination unit 11, a lens module 12, an imaging device 13, an imaging device control unit 14, a lens control unit 16, registers 15 and 17, and a communication I/I. And an F (interface) unit 18.

The illumination unit 11 irradiates the work W with light. The light emitted from the illumination unit 11 is reflected on the surface of the work W and enters the lens module 12. The illumination unit 11 may be omitted.

The lens module 12 is an optical system for forming an image of the light from the work W on the image pickup surface 13a of the image pickup device 13. The focus position of the lens module 12 is variable within a predetermined movable range. The focal position is the position of a point where an incident light ray parallel to the optical axis intersects the optical axis.

The lens module 12 includes a lens 12a, a lens group 12b, a lens 12c, a movable portion 12d, and a focus adjusting portion 12e. The lens 12a is a lens for changing the focal position of the lens module 12. The focus adjustment unit 12e controls the lens 12a to adjust the focus position of the lens module 12.

The lens group 12b is a lens group for changing the focal length. The zoom magnification is controlled by changing the focal length. The lens group 12b is installed in the movable portion 12d and is movable along the optical axis direction. The lens 12c is a lens fixed at a predetermined position in the image pickup apparatus 10.

The lens control unit 16 controls the focus adjustment unit 12e so that the focus position is in accordance with the instruction stored in the register 17.

The lens control unit 16 may adjust the position of the lens group 12b by controlling the movable unit 12d so that the size of the region included in the imaging field of view of the work W is substantially constant. In other words, the lens control unit 16 can control the movable unit 12d so that the size of the region of the work W included in the imaging visual field falls within a predetermined range. The lens control unit 16 may adjust the position of the lens group 12b according to the distance between the imaging position and the work W. In this embodiment, zoom adjustment is not essential.

The image sensor 13 is a photoelectric conversion element such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor, and generates an image signal by receiving light from the work W via the lens module 12.

The image sensor control unit 14 generates image data based on the image signal from the image sensor 13 when the focus position is adjusted by the focus adjustment unit 12e. At this time, the image sensor control unit 14 opens and closes the shutter so that the shutter speed (exposure time) is set in advance, and generates image data of the preset resolution. Information indicating the shutter speed and the resolution is stored in the register 15 in advance.

The communication I/F unit 18 sends and receives data to and from the image processing device 20. The communication I/F unit 18 receives an imaging instruction from the image processing device 20. The communication I/F unit 18 transmits the image data generated by the image sensor control unit 14 to the image processing device 20.

Returning to FIG. 1, the PLC 30 is connected to the image processing device 20 and controls the image processing device 20. For example, the PLC 30 controls the timing for the image processing apparatus 20 to output an image capturing command (image capturing trigger) to the image capturing apparatus 10.

The input device 40 and the display device 50 are connected to the image processing device 20. The input device 40 receives user's inputs regarding various settings of the inspection system 1. The display device 50 displays information regarding the setting of the inspection system 1, the result of the image processing of the work W by the image processing device 20, and the like.

The image processing device 20 performs image processing on the image captured by the imaging device 10. The image processing device 20 includes a setting unit 22, an inspection unit 25, and an evaluation unit 26.

The setting unit 22 sets the first area and the second area in the image indicated by the image data acquired from the image pickup apparatus 10 according to the input to the input apparatus 40. The first area is an area to be inspected by the inspection unit 25 (hereinafter, referred to as “inspection area”). The second area is an area (hereinafter, referred to as “reliability evaluation area”) used when evaluating the reliability of focus of the work W on the inspection target portion.

The inspection area is set according to the inspection target part. For example, when the work W is a glass substrate and it is desired to inspect for scratches near the center of the upper surface of the glass substrate, an area including the vicinity of the center of the upper surface is set as the inspection area.

Since the reliability evaluation area is used to evaluate the focus of the inspection target portion of the work W, an area having the same height as the inspection area of the inspection target portion of the work W and a high contrast is set. ..

The inspection unit 25 inspects the work W based on the inspection area in the inspection image indicated by the inspection image data received from the imaging device 10, and outputs the inspection result. Specifically, the inspection unit 25 inspects the work W by performing a process according to a pre-registered inspection program on the inspection area. The inspection unit 25 may perform the inspection using a known technique. When the inspection item is the presence/absence of scratches, the inspection result indicates “with scratches” or “without scratches”. When the inspection item is a dimension, the inspection result indicates whether or not the measured value of the dimension is within a predetermined range.

The evaluation unit 26 evaluates the reliability of focusing on the inspection target portion of the work W based on the reliability evaluation area in the inspection image represented by the inspection image data, and outputs the evaluation result. Specifically, the evaluation unit 26 evaluates the reliability of focusing on the inspection target portion of the work W by performing processing according to the evaluation program registered in advance on the reliability evaluation area. The evaluation unit 26 calculates, for example, an evaluation value that increases as the reliability increases, and outputs an evaluation result including the evaluation value.

As described above, the inspection system 1 according to the embodiment includes the lens module 12 whose focal position is variable, the image sensor 13 which generates an image by receiving light from the work W via the lens module 12, and the focus. A focus adjustment unit 12e for adjusting the position is provided. Furthermore, the inspection system 1 includes an inspection unit 25 and an evaluation unit 26. The inspection unit 25 inspects the work W based on the inspection region in the inspection image generated when the focus position is adjusted by the focus adjustment unit 12e, and outputs the inspection result. The evaluation unit 26 evaluates the reliability of focusing on the inspection target portion of the work W based on the reliability evaluation region of the inspection image, and outputs the evaluation result.

With this, by checking the inspection result and the evaluation result, the risk of overlooking the defect of the work W can be reduced. For example, even when the inspection result indicates “no scratch”, when the evaluation result indicating that the focus of the work W on the inspection target portion is low in reliability is obtained, the worker shifts the focus position. It is possible to recognize that the inspection cannot be performed accurately due to the fact that As a result, the worker can take appropriate measures such as reinspection of the work W.

§2 Specific example <A. Configuration example for autofocus>
FIG. 3 is a schematic diagram for explaining autofocus. To simplify the description, FIG. 3 shows only one lens of the lens module 12.

As shown in FIG. 3, the distance from the principal point O of the lens module 12 to the target surface (the surface of the work W) is a, the distance from the principal point O of the lens module 12 to the imaging surface 13a is b, and the lens module The distance (focal length) from the principal point O of 12 to the focal position (rear focal position) F of the lens module 12 is f. When the image of the work W is formed at the position of the imaging surface 13a, the following expression (1) is established.
1/a+1/b=1/f (1)
That is, when the formula (1) is satisfied, an image focused on the surface of the work W can be captured. “In focus” means that an image of the work W is formed on the image pickup surface 13a (see FIG. 2) of the image pickup device 13.

The distance between the imaging surface 13a and the surface of the work W may change according to the height of the surface of the work W. The focus position F of the lens module 12 is adjusted in order to obtain an image focused on the surface of the work W even when the distance between the imaging surface 13a and the surface of the work W changes. The method of adjusting the focal position F of the lens module 12 includes the following method (A) and method (B).

The method (A) is a method in which at least one lens (for example, the lens 12a) forming the lens module 12 is translated in the optical axis direction. According to the method (A), the focal point F changes while the principal point O of the lens module 12 moves in the optical axis direction. As a result, the distance b changes. An image focused on the surface of the work W is obtained at the focal position F corresponding to the distance b satisfying the expression (1).

Method (B) is a method of changing the refraction direction of the lens 12a fixed at a fixed position. According to the method (B), the focal position F changes as the focal length f of the lens module 12 changes. An image focused on the surface of the work W is obtained at the focal position F corresponding to the focal length f that satisfies Expression (1).

The configuration of the lens 12a for changing the focal position F of the lens module 12 is not particularly limited. Below, the example of a structure of the lens 12a is demonstrated.

FIG. 4 is a diagram showing an example of a lens module whose focal position is variable. In the example shown in FIG. 4, the lens 12a forming the lens module 12 is moved in parallel. However, at least one lens (at least one of the lens 12a, the lens group 12b, and the lens 12c) that configures the lens module 12 may be translated.

By using the lens 12a having the configuration shown in FIG. 4, the focal position F of the lens module 12 changes according to the above method (A). That is, in the configuration shown in FIG. 4, the focus adjustment unit 12e moves the lens 12a along the optical axis direction. By moving the position of the lens 12a, the focus position F of the lens module 12 changes.

In FIG. 4, an example of one lens 12a is shown. Usually, the focus adjusting lens is often composed of a plurality of lens groups. However, also in the combined lens, the focus position F of the lens module 12 can be changed by controlling the movement amount of at least one lens forming the combined lens.

FIG. 5 is a diagram showing another example of a lens module whose focal position is variable. By using the lens 12a having the configuration shown in FIG. 5, the focal position F of the lens module 12 changes according to the above method (B).

The lens 12a shown in FIG. 5 is a liquid lens. The lens 12a includes a translucent container 70, electrodes 73a, 73b, 74a, 74b, insulators 75a, 75b, and insulating layers 76a, 76b.

A conductive space 71, such as water, and an insulating liquid 72, such as oil, are filled in the sealed space inside the transparent container 70. The conductive liquid 71 and the insulating liquid 72 are not mixed and have different refractive indexes.

The electrodes 73a and 73b are fixed between the insulators 75a and 75b and the translucent container 70, respectively, and are located in the conductive liquid 71.

The electrodes 74a and 74b are arranged near the ends of the interface between the conductive liquid 71 and the insulating liquid 72. An insulating layer 76a is interposed between the electrode 74a and the conductive liquid 71 and the insulating liquid 72. An insulating layer 76b is interposed between the electrode 74b and the conductive liquid 71 and the insulating liquid 72. The electrodes 74a and 74b are arranged at positions symmetrical with respect to the optical axis of the lens 12a.

In the configuration shown in FIG. 5, the focus adjustment unit 12e includes a voltage source 12e1 and a voltage source 12e2. The voltage source 12e1 applies the voltage Va between the electrode 74a and the electrode 73a. The voltage source 12e2 applies the voltage Vb between the electrode 74b and the electrode 73b.

When the voltage Va is applied between the electrode 74a and the electrode 73a, the conductive liquid 71 is pulled by the electrode 74a. Similarly, when the voltage Vb is applied between the electrode 74b and the electrode 73b, the conductive liquid 71 is pulled by the electrode 74b. As a result, the curvature of the interface between the conductive liquid 71 and the insulating liquid 72 changes. Since the conductive liquid 71 and the insulating liquid 72 have different refractive indexes, the focus position F of the lens module 12 changes as the curvature of the interface between the conductive liquid 71 and the insulating liquid 72 changes.

The curvature of the interface between the conductive liquid 71 and the insulating liquid 72 depends on the magnitude of the voltages Va and Vb. Therefore, the search unit 24 changes the focus position F of the lens module 12 by controlling the magnitudes of the voltages Va and Vb.

Normally, the voltage Va and the voltage Vb are controlled to the same value. As a result, the interface between the conductive liquid 71 and the insulating liquid 72 changes symmetrically with respect to the optical axis. However, the voltage Va and the voltage Vb may be controlled to different values. As a result, the interface between the conductive liquid 71 and the insulating liquid 72 becomes asymmetric with respect to the optical axis, and the orientation of the imaging visual field of the imaging device 10 can be changed.

Furthermore, a liquid lens and a solid lens may be combined. In this case, the focus position F of the lens module 12 is changed by using both the method (A) and the method (B) described above.

<B. Hardware configuration of image processing device>
FIG. 6 is a block diagram showing an example of the hardware configuration of the image processing apparatus according to the embodiment. The image processing apparatus 20 of the example illustrated in FIG. 6 includes a CPU (Central Processing Unit) 210 that is an arithmetic processing unit, a main memory 232 and a hard disk 234 that are storage units, a camera interface 216, an input interface 218, and a display controller. 220, PLC interface 222, communication interface 224, and data reader/writer 226. These units are connected to each other via a bus 228 so that they can communicate with each other.

The CPU 210 expands the program (code) stored in the hard disk 234 into the main memory 232 and executes these in a predetermined order to perform various calculations. The control program 236 includes an inspection program for inspecting the work W based on the inspection image and an evaluation program for evaluating the reliability of focusing on the work W.

The main memory 232 is typically a volatile storage device such as a DRAM (Dynamic Random Access Memory), and in addition to the program read from the hard disk 234, image data and work acquired by the imaging device 10 Holds data etc. Further, the hard disk 234 may store various setting values and the like. In addition to the hard disk 234 or in place of the hard disk 234, a semiconductor storage device such as a flash memory may be adopted.

The camera interface 216 mediates data transmission between the CPU 210 and the imaging device 10. That is, the camera interface 216 is connected to the imaging device 10 for imaging the work W and generating image data. More specifically, the camera interface 216 includes an image buffer 216a for temporarily storing image data from the image pickup apparatus 10. Then, when the image data of a predetermined number of frames is accumulated in the image buffer 216a, the camera interface 216 transfers the accumulated data to the main memory 232. The camera interface 216 also sends an image pickup command to the image pickup apparatus 10 in accordance with an internal command generated by the CPU 210.

The input interface 218 mediates data transmission between the CPU 210 and the input device 40. That is, the input interface 218 receives an operation command given by the operator operating the input device 40.

The display controller 220 is connected to the display device 50 and notifies the user of the result of processing in the CPU 210. That is, the display controller 220 controls the screen of the display device 50.

The PLC interface 222 mediates data transmission between the CPU 210 and the PLC 30. More specifically, the PLC interface 222 transmits the control command from the PLC 30 to the CPU 210.

The communication interface 224 mediates data transmission between the CPU 210 and the console (or personal computer or server device). The communication interface 224 is typically composed of Ethernet (registered trademark) or USB (Universal Serial Bus). As will be described later, instead of installing the program stored in the memory card 206 in the image processing apparatus 20, the program downloaded from a distribution server or the like via the communication interface 224 is installed in the image processing apparatus 20. May be.

The data reader/writer 226 mediates data transmission between the CPU 210 and the memory card 206 which is a recording medium. That is, the memory card 206 circulates in a state in which a program executed by the image processing apparatus 20 is stored, and the data reader/writer 226 reads the program from the memory card 206. In addition, the data reader/writer 226 writes the image data acquired by the imaging device 10 and/or the processing result in the image processing device 20 to the memory card 206 in response to the internal command of the CPU 210. The memory card 206 is a general-purpose semiconductor storage device such as SD (Secure Digital), a magnetic storage medium such as a flexible disk (Flexible Disk), or an optical storage medium such as a CD-ROM (Compact Disk Read Only Memory). Etc.

<C. Functional configuration of image processing device>
An example of the functional configuration of the image processing apparatus 20 will be described with reference to FIG. 7. FIG. 7 is a diagram illustrating an example of the functional configuration of the image processing apparatus. As shown in FIG. 7, the image processing device 20 includes a command generation unit 21, a setting unit 22, a calculation unit 23, a search unit 24, an inspection unit 25, an evaluation unit 26, a determination unit 27, The output unit 28 and the storage unit 230 are included. The command generation unit 21, the setting unit 22, the calculation unit 23, the search unit 24, the inspection unit 25, the evaluation unit 26, and the determination unit 27 are realized by the CPU 210 shown in FIG. 6 executing the control program 236. The storage unit 230 includes a main memory 232 and a hard disk 234 shown in FIG. The output unit 28 is configured by the display controller 220 shown in FIG.

The command generation unit 21 receives a control command from the PLC 30 and outputs an imaging command (imaging trigger) to the imaging device 10. The outline of the setting unit 22 is as described above.

The calculation unit 23 calculates the degree of focus from the image data generated by the imaging device 10. The focus degree is a degree indicating how much the object is in focus, and is calculated using various known methods. For example, the calculation unit 23 extracts a high frequency component by applying a high pass filter to the image data, and calculates an integrated value of the extracted high frequency components as a focus degree. Such a focus degree indicates a value that depends on the difference in brightness of the image.

The search unit 24 searches for a focus position which is a focus position where the work W is focused. Specifically, the search unit 24 acquires, from the calculation unit 23, the focus degree of each of the plurality of image data generated by changing the focal position of the lens module 12. The search unit 24 determines the focus position at which the acquired degree of focus reaches a peak as the focus position. The search unit 24 specifies the image data when the focal position of the lens module 12 is the in-focus position as the inspection image data. That is, the inspection image data is image data generated when the focus position is adjusted to the in-focus position by the focus adjustment unit 12e.

As methods for searching the in-focus position, there are a hill climbing method and a full scan method, and either method may be used.

The hill climbing method is a focus at which the focus is maximized while changing the focus position of the lens module 12 within the set search range and ending the search when the focus position at which the focus is maximized is found. This is a method of determining the position as the in-focus position. Specifically, the hill-climbing method is based on the magnitude relationship between the focus degree at the focus position at the start of the search and the focus degree at the adjacent focus position, and the direction of the focus position at which the focus degree increases becomes the search direction. decide. Furthermore, the hill climbing method sequentially calculates the difference between the focus degree at the previous focus position and the focus degree at the next focus position while changing the focus position in the search direction. The focus position at the time of negative change is determined as the focus position.

In the hill climbing method, the search unit 24 may specify the image data having the maximum focus degree as the inspection image data.

The all-scan method is to change the focal position of the lens module 12 over the entire set search range, obtain the in-focus degree at each in-focus position, and set the in-focus position to be the in-focus position with the maximum in-focus degree. It is a way to decide. The full scan method also includes a method of performing a coarse second search process and then a fine second search process. The first search process is a process of changing the focus position at a coarse pitch interval over the entire search range to search for the focus position having the maximum focus degree. The second search process is a process of changing the focus position at fine pitch intervals in the entire local range including the focus position searched in the first search process, and searching the focus position with the maximum focus degree as the focus position. Is.

In the full scan method, the search unit 24 stores the image data of each focus position, and specifies the image data of the focus position having the maximum focus degree as the inspection image data from the stored image data. To do. Alternatively, the search unit 24 instructs the command generation unit 21 to output a command for adjusting the focus position to the in-focus position and outputting an image, and the image data received from the imaging device 10 according to the command is the inspection image data. May be specified as

The outline of the inspection unit 25 and the evaluation unit 26 is as described above. That is, the inspection unit 25 inspects the work W based on the inspection area in the inspection image indicated by the inspection image data specified by the search unit 24, and outputs the inspection result. The evaluation unit 26 evaluates the reliability of focusing on the inspection target portion of the work W based on the reliability evaluation region of the inspection image indicated by the inspection image data specified by the search unit 24, and displays the evaluation result. Output.

The determination unit 27 makes a comprehensive determination of the work W based on the inspection result output from the inspection unit 25 and the evaluation result output from the evaluation unit 26. The determination unit 27 determines whether the inspection result output from the inspection unit 25 satisfies a predetermined first criterion and the evaluation result output from the evaluation unit 26 satisfies a predetermined second criterion. It is determined that W is a good product.

The determination unit 27 determines that the work W is a defective product when the inspection result does not satisfy the first standard and the evaluation result satisfies the second standard. Further, when the evaluation result does not satisfy the second criterion, the determination unit 27 determines that the automatic adjustment of the focus position has a problem and the inspection cannot be performed accurately.

The output unit 28 outputs the determination result of the determination unit 27. For example, the output unit 28 causes the display device 50 to display the determination result. The output unit 28 may also display the inspection result and the evaluation result on the display device 50.

The storage unit 230 stores various data, programs and the like. For example, the storage unit 230 stores the image data acquired from the imaging device 10 and the image data that has been subjected to predetermined processing. The storage unit 230 may store the inspection result by the inspection unit 25, the evaluation result by the evaluation unit 26, and the determination result by the determination unit 27. Further, the storage unit 230 stores a program for causing the image processing apparatus 20 to execute various types of processing.

<D. Workpiece examples and autofocus issues>
FIG. 8 is a diagram schematically showing the image pickup of the work W by the image pickup apparatus. In the example shown in FIG. 8, the work W has a region W1 and a region W2. The region W1 is, for example, the surface of a transparent body (glass or the like). The region W2 is a region surrounding the region W1 and is, for example, the surface of the housing of the electronic device. As an example of such a work W, an electronic device having a display (a smartphone or a tablet in one example) can be cited. That is, the area W1 can be a display screen. Moreover, the region W1 does not have a clear pattern. That is, the area W1 is a plain area.

When it is desired to inspect the area W1, the inspection area A1 is set in the area W1. An area including the inspection area A1 is imaged by the imaging device 10, and the image of the inspection area A1 is a target of image processing by the image processing apparatus 20. The image processing apparatus 20 uses the image of the inspection area A1 to inspect whether the inspection area A1 has scratches, dirt, or foreign matter.

If the image is taken in a state where the inspection area A1 is out of focus, there is a possibility that a scratch or the like in the inspection area A1 cannot be detected from the acquired image. In order to perform a highly accurate inspection, it is required to evaluate whether or not the image is focused on the inspection area A1. However, as in the above example, when the inspection area A1 is a part of the plain area, a clear pattern is not formed in the inspection area A1. In such a case, since the contrast in the inspection area A1 is low, it is difficult to evaluate whether or not the inspection area A1 is in focus only with the image of the inspection area A1.

<E. Setting inspection area and reliability evaluation area>
According to the present embodiment, the setting unit 22 of the image processing apparatus 20 sets the inspection area and the reliability evaluation area in advance for the work W.

The worker places the reference work W0 at a predetermined position on the stage 90 (see FIG. 1) in a predetermined posture. The image processing device 20 outputs an imaging command to the imaging device 10 and acquires reference image data from the imaging device 10. The reference image data indicates a reference image including the reference work W0 placed at a predetermined position in a predetermined posture.

The setting unit 22 of the image processing device 20 causes the display device 50 to display the reference image represented by the reference image data acquired from the imaging device 10, and prompts the operator to specify the inspection region and the reliability evaluation region.

FIG. 9 is a diagram showing an example of a setting screen for the inspection area and the reliability evaluation area. As shown in FIG. 9, the setting unit 22 causes the screen of the display device 50 to display the reference image 80 indicated by the reference image data acquired from the imaging device 10.

The setting unit 22 sets the inspection area A1 and the reliability evaluation area B1 according to the input to the input device 40. For example, the worker inputs four vertices of the inspection area A1 and the reliability evaluation area B1 which are rectangular. The operator designates a region having the same height as the inspection region A1 of the reference work W0 and including a high contrast as the reliability evaluation region B1. In the example shown in FIG. 9, a region including the edge portion of the reference work W0 is designated as the reliability evaluation region B1. The high-contrast portion includes, in addition to the edge portion, a character printed on the surface, a pattern formed on the surface, a portion to which parts such as screws are attached, and the like.

In the example shown in FIG. 9, a rectangular inspection area A1 and a reliability evaluation area B1 are set, but the shape of each area is not limited to this. For example, the shape of at least one of the inspection area A1 and the reliability evaluation area B1 may be circular or any free shape capable of forming an area. Further, at least one of the inspection area A1 and the reliability evaluation area B1 does not have to be limited to a single area. For example, at least one of the inspection area A1 and the reliability evaluation area B1 may be a plurality of areas that exist in a distributed manner.

FIG. 10 is a diagram showing another example of a setting screen for the inspection area and the reliability evaluation area. In the example shown in FIG. 10, a frame-shaped reliability evaluation area B1 is set along the edge portion of the reference work W0.

The setting unit 22 generates information for identifying each of the set inspection area A1 and reliability evaluation area B1, and stores the generated information in the storage unit 230.

<F. Evaluation method>
Next, a method of evaluating reliability by the evaluation unit 26 will be described. The evaluation unit 26 calculates an evaluation value indicating the reliability of the focus on the inspection target portion of the work W based on the focus degree of the reliability evaluation area B1 in the inspection image represented by the inspection image data. The focus degree is, for example, an integrated value of high frequency components extracted from the image of the reliability evaluation area B1.

For example, the evaluation unit 26 calculates, as an evaluation value, a ratio (=c/d) between the focus degree c calculated from the reliability evaluation area B1 of the inspection image and a predetermined reference focus degree d. In this case, the larger the evaluation value, the higher the reliability of focusing on the inspection target portion of the work W. The reference focus degree is, for example, the focus degree calculated from the reliability evaluation area B1 in the image focused on the inspection target portion of the reference work W0, and is calculated in advance by an experiment.

Alternatively, when the search unit 24 searches for the in-focus position according to the full scan method, the evaluation unit 26 causes the in-focus level g and the second in-focus level g of the first peak of the in-focus level waveform obtained in the in-focus position search process. The ratio (=g/h) of the peak to the focusing degree h may be calculated as the evaluation value. The focus degree waveform is a waveform showing a change in the focus degree with respect to the focus position when the focus position of the lens module 12 is changed. The first peak is the peak with the highest degree of focus. The second peak is the peak having the second highest focus degree.

FIG. 11 is a diagram showing an example of the focus degree waveform. The focus degree waveform of the example shown in FIG. 11 includes two peaks at focus positions F1 and F2. The focus position F1 is the focus position when focusing on the inspection target portion of the work W. Therefore, when the autofocus process is normally performed, the focus degree waveform includes only one peak at the focus position F1. However, for some reason, a peak may occur at a focus position different from the focus position F1. For example, when a sheet on which a high-contrast pattern is formed is reflected in the inspection image, a peak occurs at a focus position different from the focus position F1.

When the focus degree waveform of the example shown in FIG. 11 is obtained, the focus position F2 different from the focus position F1 is erroneously determined as the focus position, and the image data when adjusted to the focus position F2 is the inspection image data. Can be specified as

Therefore, the evaluation unit 26 acquires the focus degree calculated from the reliability evaluation area B1 of the inspection image as the focus degree g of the first peak. Furthermore, the evaluation unit 26 acquires the focus degree of the second peak having the second highest focus degree as the focus degree h of the second peak. The evaluation unit 26 calculates an evaluation value (=g/h) based on the focusing degrees g and h.

In the above example, an evaluation value that increases as the reliability of focusing of the inspection target portion of the work W increases. However, the evaluation unit 26 may calculate an evaluation value that becomes smaller as the reliability of focusing of the inspection target portion of the work W becomes higher.

In addition, the evaluation unit 26 may calculate the evaluation value using a known technique. For example, the evaluation unit 26 uses the technology described in International Publication No. 2017/056557 (Patent Document 2), JP 2010-78681 A (Patent Document 3), and JP 10-170817 A (Patent Document 4). You may use and calculate an evaluation value.

<G. Overall judgment method>
As described above, the determination unit 27 of the image processing apparatus 20 determines that the inspection result satisfies the predetermined first criterion and the evaluation result output from the evaluation unit 26 satisfies the predetermined second criterion. First, it is determined that the work W is a good product. For example, when the inspection item is the presence/absence of scratches, the first standard indicates that the inspection result is “no damage”. When the inspection item is a dimension, the first standard indicates that the measured value of the dimension is within a predetermined range. Furthermore, when the evaluation result includes an evaluation value that increases as the reliability of focusing on the inspection target portion of the work W increases, the second criterion indicates that the evaluation value exceeds a predetermined threshold value.

The first standard and the second standard are created in advance and stored in the storage unit 230. The determination unit 27 reads the first criterion and the second criterion from the storage unit 230 and makes a comprehensive determination.

<H. Flow of inspection>
Next, the flow of the inspection process according to the present embodiment will be described with reference to FIG. FIG. 12 is a flowchart showing an example of the flow of the inspection process of the inspection system according to the embodiment. Prior to the inspection method shown in FIG. 12, the setting unit 22 of the image processing apparatus 20 sets the inspection area A1 and the reliability evaluation area B1 using the image data including the reference work W0.

Each time the workpiece W to be inspected is transported to the stage 90 (see FIG. 1) by a transport device (not shown), the inspection process shown in FIG. 12 is executed. In the present embodiment, the work W is placed on the stage 90 at a predetermined position in a predetermined posture by the transfer device.

First, the imaging device 10 and the image processing device 20 execute a focus position search process (step S1). In step S1, the lens control unit 16 of the imaging device 10 changes the focal position of the lens module 12 within the search range. The calculation unit 23 of the image processing apparatus 20 calculates the focus degree of the entire area for each of the plurality of image data generated by changing the focus position. The search unit 24 of the image processing device 20 searches for a focus position at which the calculated focus degree has a peak as the focus position.

Next, the search unit 24 identifies the image data when the focus position of the lens module 12 is adjusted to the in-focus position as inspection image data (step S2).

Next, the inspection unit 25 of the image processing apparatus 20 inspects the work W based on the inspection area A1 in the inspection image indicated by the inspection image data, and outputs the inspection result (step S3).

Further, the evaluation unit 26 of the image processing apparatus 20 calculates an evaluation value indicating the reliability of focus of the work W on the inspection target portion based on the reliability evaluation area B1 in the inspection image, and the calculated evaluation value. The evaluation result including is output (step S4). The processing order of step S3 and step S4 is not limited to this, and step S3 may be executed after step S4, or step S3 and step S4 may be executed in parallel.

Next, the determination unit 27 of the image processing apparatus 20 makes a comprehensive determination based on the inspection result and the evaluation result (step S5). After that, the output unit 28 displays the determination result on the display device 50 (step S6). After step S6, the inspection process ends.

Note that the determination result may be output to the PLC 30 other than the display device 50 and used for controlling other devices. For example, when the determination result indicates that the work W is a non-defective product, the transport device (not shown) transports the work W on the transport path for transporting the work W to the next process. When the determination result indicates that the work W is a defective product, the transport device transports the work W to the defective product storage space. When the determination result indicates that the inspection has not been performed accurately, the transfer device transfers the work W to the re-inspection product storage area.

§3 Modification Example <Modification Example 1>
In the above description, the workpiece W to be inspected is assumed to be placed in a predetermined posture on the stage 90 by a transfer device (not shown). However, when the transport accuracy of the transport device is low, the position and orientation of the work W included in the inspection image may change. Therefore, the image processing device of the inspection system according to the first modification uses the inspection area A1 for the inspection image and the reliability evaluation based on the deviation of the position and orientation of the work W in the inspection image with respect to the position and orientation of the reference work in the reference image. The relative position and orientation of the area B1 is corrected. As a result, even if the position and orientation of the work W included in the inspection image changes, it is possible to suppress deterioration of inspection accuracy and reliability evaluation accuracy.

FIG. 13 is a schematic diagram showing an inspection system according to Modification 1. The inspection system 1A according to Modification 1 is different from the inspection system 1 shown in FIG. 1 in that an image processing apparatus 20A is provided instead of the image processing apparatus 20. The image processing apparatus 20A is different from the image processing apparatus 20 shown in FIG. 1 in that it includes a setting unit 22A instead of the setting unit 22 and further includes a correction unit 29.

Like the setting unit 22 described above, the setting unit 22A sets the inspection area A1 and the reliability evaluation area B1 from the reference image. Further, the setting unit 22A sets a model area from the reference image. The model area is an area including a characteristic portion of the reference work W0 placed in a predetermined posture at a predetermined position. The characteristic portion is a portion capable of specifying the position and orientation of the reference work W0.

FIG. 14 is a diagram showing an example of a setting screen for the inspection area, the reliability evaluation area, and the model area. In the example shown in FIG. 14, in the reference image 80, regions including two non-adjacent corners of the four corners of the rectangular reference work W0 in plan view are set as model regions C1 and C2. The setting unit 22A stores in the storage unit 230 each image of the set model regions C1 and C2 and information indicating the position and orientation of the model regions C1 and C2 in the reference image.

Next, the processing of the correction unit 29 will be described with reference to FIG. FIG. 15 is a diagram illustrating the processing of the correction unit.

The correction unit 29 searches the inspection image 81 for the same partial image as the images of the model regions C1 and C2 in the reference image 80 using a known template matching method. The correction unit 29 reads the images of the model areas C1 and C2 as the first and second template images from the storage unit 230, respectively. The correction unit 29 searches the inspection image 81 for the first partial image D1 having the same pattern as the first template image corresponding to the model region C1, and at the same time, the second portion having the same pattern as the second template image corresponding to the model region C2. The image D2 is searched from the inspection image 81.

Specifically, the correction unit 29 performs the correlation calculation between the first template image and the inspection image 81 while changing the position and orientation of the first template image, and the first template having the highest degree of similarity indicated by the correlation value. Search the position and orientation of the image. Then, the correction unit 29 specifies the image of the region overlapping the first template image of the searched position and orientation as the first partial image D1. Similarly, by the method, the correction unit 29 identifies the image of the region overlapping the second template image of the position and orientation having the highest degree of similarity indicated by the correlation value as the second partial image D2.

As the correlation value, known SSD (Sum of Squared Difference), SAD (Sum of Absolute Difference), NCC (Normalized Cross-Correlation), etc. can be used. When SSD or SAD is used as the correlation value, the correction unit 29 may search for the position and orientation of the template image having the minimum correlation value. When NCC is used as the correlation value, the correction unit 29 may search the position and orientation of the template image whose correlation value is closest to 1.

The correction unit 29 compares the position and orientation of the searched partial images D1 and D2 with the position and orientation of the model areas C1 and C2, respectively, to determine the position and orientation of the reference work W0 in the reference image 80 (hereinafter, referred to as “reference position”). The deviation of the position/orientation of the work W in the inspection image 81 with respect to the “orientation” is calculated (calculated). The deviations indicate deviation amounts ΔX, ΔY, and Δθ in the X direction, the Y direction, and the rotation direction (θ direction), respectively.

The correction unit 29 corrects the relative position and orientation of the inspection area A1 and the reliability evaluation area B1 with respect to the inspection image 81 based on the calculated deviation. That is, the correction unit 29 corrects the position and orientation of the inspection area A1 and the reliability evaluation area B1 by the calculated deviation. Specifically, the correction unit 29 translates the inspection area A1 and the reliability evaluation area B1 by ΔX in the X direction and ΔY in the Y direction with the inspection image 81 fixed, and Δθ. Only rotate and move.

The correction unit 29 may correct the position and orientation of the inspection image 81 while fixing the inspection area A1 and the reliability evaluation area B1. In this case, the correction unit 29 may perform the reverse conversion of the position and orientation of the inspection area A1 and the reliability evaluation area B1 on the position and orientation of the inspection image 81.

FIG. 16 is a flowchart showing the flow of the inspection process of the inspection system according to the first modification. The flowchart shown in FIG. 16 differs from the flowchart shown in FIG. 12 in that it further includes steps S11 and S12.

When the inspection image data is acquired from the imaging device 10 (step S2), the correction unit 29 of the image processing device 20A calculates the deviation of the position and orientation of the work W in the inspection image 81 from the reference position and orientation in step S11.

Next, in step S12, the correction unit 29 corrects the relative position and orientation of the inspection area A1 and the reliability evaluation area B1 with respect to the inspection image 81 based on the calculated deviation. Then, the inspection of the workpiece W is executed using the corrected inspection area A1 (step S3), and the reliability evaluation is executed using the corrected reliability evaluation area B1 (step S4).

In the above description, the model areas C1 and C2 and the reliability evaluation area B1 are set separately. However, the same area as the reliability evaluation area B1 may be set as the model area. That is, the reliability evaluation area B1 may be shared as a model area.

<Modification 2>
The inspection system according to Modification 2 is a further modification of the inspection system according to Modification 1. In the inspection system according to Modification 2, the determination unit 27 performs the following processing.

When the inspection result satisfies the first criterion, the evaluation result satisfies the second criterion, and the correlation value calculated by the correcting unit 29 satisfies the predetermined third criterion, the determination unit 27 determines that the workpiece It is determined that W is a good product. When the correlation value calculated by the correction unit 29 does not satisfy the third criterion, the determination unit 27 determines that the work W is not normally imaged.

The correlation value calculated by the correction unit 29 indicates the degree of similarity between the template images of the model areas C1 and C2 and the partial images D1 and D2 searched from the inspection image. When the degree of similarity indicated by the correlation value is low, there is a high possibility that the work W to be inspected cannot be normally imaged for some reason. For example, the position of the work W on the stage 90 is largely deviated from the predetermined position, so that the work W is not included in the image.

The third criterion is, for example, a criterion that the degree of similarity indicated by the correlation value between the template images of the model areas C1 and C2 and the partial images D1 and D2 is higher than a predetermined degree of similarity. For example, when the higher the degree of similarity is, the smaller the correlation value is, the third criterion indicates that the correlation value is lower than a predetermined threshold value.

According to the second modification, it is possible to further reduce the risk of overlooking a defective work W as a non-defective product even though the work W is not normally imaged.

<Modification 3>
The inspection system according to Modification 3 is a further modification of the inspection system according to Modification 1. In the inspection system according to Modification 3, the autofocus process is executed using the reliability evaluation area B1 corrected by the correction unit 29.

FIG. 17 is a flowchart showing the flow of the inspection process of the inspection system according to the modified example 3. The flowchart shown in FIG. 17 differs from the flowchart shown in FIG. 16 in that it includes steps S21 to S23 instead of steps S2, S11 and S12, and further includes steps S24 and S25.

After step S1, the search unit 24 of the image processing apparatus 20 identifies the image data when the focus position of the lens module 12 is adjusted to the in-focus position as the correction image data in step S21.

Next, the correction unit 29 calculates the deviation of the position and orientation of the work W in the correction image indicated by the correction image data from the reference position and orientation (step S22). The correction unit 29 corrects the relative position and orientation of the inspection area A1 and the reliability evaluation area B1 with respect to the correction image based on the calculated deviation (step S23). Specifically, the correction unit 29 corrects the position and orientation of the inspection area A1 and the reliability evaluation area B1 with the correction image fixed, as in the first modification. Alternatively, the correction unit 29 may correct the position and orientation of the correction image while the inspection area A1 and the reliability evaluation area B1 are fixed.

Next, the image processing device 20 executes a focus position search process based on the corrected reliability evaluation area B1 (step S24). Specifically, the calculation unit 23 calculates the degree of focus of the reliability evaluation area B1 of each of the plurality of image data. The search unit 24 determines the focus position where the calculated focus degree is the peak, as the focus position.

Next, the search unit 24 identifies the image data generated at the searched in-focus position as inspection image data (step S25). After that, the inspection of the work W is executed using the corrected inspection area A1 in the inspection image indicated by the inspection image data (step S3), and the reliability is evaluated using the corrected reliability evaluation area B1. Is executed (step S4).

According to the third modification, the in-focus position searching process is executed again based on the corrected reliability evaluation area B1, and the inspection image data is generated. Therefore, it becomes easy to obtain the inspection image data focused on the inspection target portion.

<Other modifications>
In the above description, the output unit 28 outputs the determination result by the determination unit 27. However, the inspection system may not include the determination unit 27, and the output unit 28 may output the inspection result by the inspection unit 25 and the evaluation result by the evaluation unit 26. Also by this, the operator can recognize that there is some problem in the adjustment of the focal position and the inspection cannot be performed accurately by confirming the evaluation result. As a result, it is possible to reduce the risk of overlooking a defective work W as a non-defective product by an inspection based on an image focused on a position different from the inspection target part of the work W.

In the above description, the search unit 24 searches for the in-focus position where the work W is in focus, based on a plurality of image data generated by changing the focal position of the lens module 12. However, the imaging device 10 may include a distance measuring sensor that measures the distance to the work W, and the search unit 24 may search for the in-focus position based on the measurement result of the distance measuring sensor. The distance-measuring sensor, for example, emits infrared rays or ultrasonic waves toward the work W, and then is reflected by the work W and returned to the work W based on the distance a from the lens module 12 to the work W (see FIG. 3). Measurement). The search unit 24 may determine the focus position F where the measured distance a satisfies the above expression (1) as the focus position. However, in this case, since a distance measuring sensor is required, the number of parts of the imaging device 10 increases. In order to suppress an increase in the number of components of the image pickup apparatus 10, it is preferable that the search unit 24 search for a focus position based on a plurality of image data generated by changing the focus position of the lens module 12.

In the above description, the imaging device 10 changes the focus position and outputs a plurality of image data. Then, the image processing device 20 searches for a focus position at which the inspection target portion of the work W is focused from the plurality of focus positions. However, the lens control unit 16 of the imaging device 10 may control the focal position of the lens module 12 so as to be a fixed position that is predetermined according to the type of the work W and the inspection target location. That is, the focus adjustment unit 12e adjusts the focus position of the lens module 12 to a predetermined fixed position. In this case, the image processing device 20 does not have to include the search unit 24.

Even if the focal position of the lens module 12 is adjusted to a predetermined fixed position, the imaging device 10 and the work W may be different depending on the individual difference in the size of the work W or the state of the carrying device that carries the work W. The distance from the inspection target varies. Therefore, it is not always possible to always obtain an inspection image focused on the inspection target portion of the work W. In such a case, it is possible to recognize that the image processing apparatus 20 includes the above-described evaluation unit 26, and that the inspection cannot be performed accurately due to the shift of the focus position.

§4 Appendix As described above, the embodiments and modifications include the following disclosures.

(Structure 1)
An optical system (12) whose focal position is variable,
An image sensor (13) that generates an image by receiving light from an object (W) through the optical system (12);
A focus adjustment unit (12e) for adjusting the focus position,
An inspection unit (25) that inspects the object (W) based on the first region of the inspection image generated when the focus position is adjusted by the focus adjustment unit (12e) and outputs the inspection result. , 210),
An inspection system (1), comprising: an evaluation unit (26, 210) that evaluates the reliability of focusing of the object with respect to the inspection object location based on the second region of the inspection image and outputs the evaluation result. , 1A).

(Structure 2)
Based on the deviation of the position and orientation of the object (W) in the inspection image with respect to the position and orientation of the object (W) in the reference image generated in advance, the first region and the second region with respect to the inspection image. The inspection system (1A) according to configuration 1, further comprising a correction unit (29, 210) that corrects the relative position and orientation of the region.

(Structure 3)
A determination unit (27, 210) that determines that the object is a good product when the inspection result satisfies a predetermined first standard and the evaluation result satisfies a predetermined second standard. The inspection system (1, 1A) according to Configuration 1 or 2 further provided.

(Structure 4)
The correction unit (29, 210) obtains the deviation based on a correlation value obtained by a correlation calculation between the reference image and the inspection image,
The inspection system (1A) further includes
When the inspection result satisfies a predetermined first criterion, the evaluation result satisfies a predetermined second criterion, and the correlation value satisfies a predetermined third criterion, the target The inspection system (1A) according to the configuration 2, further including a determination unit (27, 210) that determines that the product is non-defective.

(Structure 5)
The inspection system (1, 1A) according to any one of configurations 1 to 4, wherein the evaluation result includes an evaluation value calculated based on a focus degree in the second region of the inspection image.

(Structure 6)
A search unit (24) for searching a focus position which is the focus position focused on the object (W),
The inspection system (1, 1A) according to any one of configurations 1 to 5, wherein the inspection image is generated when the focus position is adjusted to the in-focus position by the focus adjustment unit (12e).

(Structure 7)
An optical system (12) whose focal position is variable,
An image sensor (13) that generates an image by receiving light from an object (W) through the optical system (12);
An inspection method in an inspection system including a focus adjustment unit (12e) for adjusting the focus position,
Inspecting the object (W) based on a first region of an inspection image generated when the focus position is adjusted by the focus adjusting unit (12e), and outputting an inspection result,
Based on a second region of the inspection image, evaluating the reliability of focusing of the object with respect to the inspection target portion, and outputting the evaluation result.

(Structure 8)
An optical system (12) whose focal position is variable,
An image sensor (13) that generates an image by receiving light from an object (W) through the optical system (12);
A program for causing a computer to execute an inspection method in an inspection system including a focus adjustment unit (12e) for adjusting the focus position,
The inspection method is
Inspecting the object (W) based on a first region of an inspection image generated when the focus position is adjusted by the focus adjusting unit (12e), and outputting an inspection result,
A step of evaluating the reliability of focusing of the object with respect to the inspection target portion based on the second region of the inspection image, and outputting the evaluation result.

Although the embodiments of the present invention have been described, the embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

1, 1A inspection system, 10 imaging device, 11 illumination unit, 12 lens module, 12a, 12c lens, 12b lens group, 12d movable part, 12e1 and 12e2 voltage source, 12e focus adjustment unit, 13 imaging device, 13a imaging surface, 14 image sensor control unit, 15, 17 register, 16 lens control unit, 18 communication I/F unit, 20, 20A image processing device, 21 command generation unit, 22, 22A setting unit, 23 calculation unit, 24 search unit, 25 Inspection unit, 26 evaluation unit, 27 judgment unit, 28 output unit, 29 correction unit, 30 PLC, 40 input device, 50 display device, 70 translucent container, 71 conductive liquid, 72 insulating liquid, 73a, 73b, 74a, 74b electrode, 75a, 75b insulator, 76a, 76b insulating layer, 80 reference image, 81 inspection image, 90 stage, 206 memory card, 216 camera interface, 216a image buffer, 218 input interface, 220 display controller, 222 PLC Interface, 224 communication interface, 226 data reader/writer, 228 bus, 230 storage unit, 232 main memory, 234 hard disk, 236 control program, A1 inspection area, B1 reliability evaluation area, C1, C2 model area, D1 first part Image, D2 second partial image, W work, W0 reference work.

Claims (8)

1. An optical system whose focal position is variable,
   An image sensor that generates an image by receiving light from an object through the optical system,
   A focus adjustment unit for adjusting the focus position,
   An inspection unit that inspects the object based on a first region of an inspection image generated when the focus position is adjusted by the focus adjustment unit and outputs an inspection result;
   An inspection system comprising: an evaluation unit that evaluates the reliability of focus of the object with respect to the inspection target location based on the second region of the inspection image and outputs the evaluation result.
2. Based on the deviation of the position and orientation of the object in the inspection image with respect to the position and orientation of the object in the reference image generated in advance, the relative position and orientation of the first region and the second region with respect to the inspection image The inspection system according to claim 1, further comprising a correction unit that corrects.
3. The determination unit that determines that the object is a non-defective product when the inspection result satisfies a predetermined first standard and the evaluation result satisfies a predetermined second standard, The inspection system according to 1 or 2.
4. The correction unit obtains the deviation based on a correlation value obtained by a correlation calculation between the reference image and the inspection image,
   The inspection system further comprises
   When the inspection result satisfies a predetermined first criterion, the evaluation result satisfies a predetermined second criterion, and the correlation value satisfies a predetermined third criterion, the target The inspection system according to claim 2, further comprising a determination unit that determines that the product is non-defective.
5. The inspection system according to any one of claims 1 to 4, wherein the evaluation result includes an evaluation value calculated based on a focus degree in the second area of the inspection image.
6. Further comprising a search unit that searches for a focus position that is the focus position that focuses on the object,
   The inspection system according to claim 1, wherein the inspection image is generated when the focus position is adjusted to the in-focus position by the focus adjustment unit.
7. An optical system whose focal position is variable,
   An image sensor that generates an image by receiving light from an object through the optical system,
   An inspection method in an inspection system including a focus adjustment unit for adjusting the focal position,
   Inspecting the object based on a first region in an inspection image generated when the focus position is adjusted by the focus adjusting unit, and outputting an inspection result,
   Based on a second region of the inspection image, evaluating the reliability of focusing of the object with respect to the inspection target portion, and outputting the evaluation result.
8. An optical system whose focal position is variable,
   An image sensor that generates an image by receiving light from an object through the optical system,
   A program for causing a computer to execute an inspection method in an inspection system including a focus adjustment unit that adjusts the focus position,
   The inspection method is
   Inspecting the object based on a first region in an inspection image generated when the focus position is adjusted by the focus adjusting unit, and outputting an inspection result,
   A step of evaluating the reliability of focusing of the object with respect to the inspection target portion based on the second region of the inspection image, and outputting the evaluation result.

Images