JP2018204999A - Image inspection device - Google Patents

Abstract

To generate a plurality of images for inspection from which different types of defects can be detected, and when subsequently adding an image for inspection displayed on a display unit or changing the images for inspection, make it possible to accurately perform defect inspection by using the images for inspection after the addition or change, while eliminating the need of a complex setting operation.SOLUTION: When images for inspection are selected, an image inspection device reads out a plurality of pieces of position information indicating the position of a non-defective part or a defective part stored therein, and refers to pixel values corresponding to the position information to update a pixel value range to be the non-defective part.SELECTED DRAWING: Figure 33

Description

  The present invention relates to an image inspection apparatus that inspects a defect of an inspection object using an image obtained by imaging the inspection object.

  Conventionally, the surface of the inspection object is irradiated with light from the illumination unit, the reflected light is received by the imaging unit, the luminance distribution of the received light is analyzed, and defects such as scratches existing on the inspection object are detected. An image inspection apparatus for inspecting the image is known.

  As this type of image inspection apparatus, there is known an image inspection apparatus that applies the principle of so-called deflectometry disclosed in Patent Document 1. The image inspection apparatus includes an illumination unit that irradiates the inspection target with pattern light whose illuminance periodically changes, and an imaging unit that images the inspection target irradiated with the pattern light. The illumination unit sequentially irradiates a plurality of pattern lights with the phase of the illuminance distribution shifted, and each time the pattern light is emitted, the imaging unit images the inspection object, and the inspection object is based on the obtained plurality of luminance images. The phase data indicating the shape of is generated. An inspection image is generated based on the obtained phase data, and the defect inspection relating to the shape of the inspection object can be performed by using the inspection image.

  As another image inspection apparatus, an image inspection apparatus using a so-called photometric stereo method disclosed in Patent Document 2 is also known. This image inspection apparatus includes three or more illumination units for illuminating an inspection object from different directions, an illumination control unit for sequentially lighting each illumination unit, and an inspection at a timing when each illumination unit irradiates light. And an imaging unit that images the object from a certain direction. A normal vector is calculated from the pixel values of each of a plurality of captured images using a photometric stereo method, and an inspection image can be generated based on the normal vector.

US Pat. No. 6,100,990 Japanese Patent Laying-Open No. 2015-232486

  By the way, since any of the image inspection apparatuses of Patent Documents 1 and 2 can generate a plurality of inspection images capable of detecting different types of defects, the user can determine whether or not there are different types of defects for a plurality of inspections. It can be inspected using an image, which is thought to lead to improved inspection accuracy.

  However, even though a plurality of inspection images can be generated, if all the generated inspection images are displayed on the display at the same time, each inspection image becomes smaller and cannot be used for inspection. Such use is not realistic. Therefore, it is assumed that the user selects a necessary inspection image and displays it on the display.

  Here, for example, it may be found later that the inspection image selected at the start of operation is not suitable for inspecting a defect, or it may be searched later for a more suitable inspection image. In that case, the user selects an inspection image that is not currently displayed and adds the inspection image to the display, or the currently displayed inspection image is currently displayed. It is conceivable to display on the display in such a way that it is changed to a non-inspection image.

  However, when such an image is added or changed, the following problem may occur. That is, for the inspection image displayed on the display, the user has already performed a threshold value setting operation for the defective area and the non-defective area. On the other hand, such an operation is not performed on the inspection image that is not displayed on the display. Therefore, when an operation for selecting an inspection image that is not displayed on the display and displaying it on the display for adding or changing the inspection image, the same operation or the like is performed again on the selected inspection image. Is necessary and complicated.

  The present invention has been made in view of such a point, and an object of the present invention is to generate a plurality of inspection images capable of detecting different types of defects and to display inspection images displayed on the display unit. When adding or changing later, it is possible to perform defect inspection with high accuracy by using the inspection image after addition or change without making complicated setting work.

  In order to achieve the above object, in the present invention, in an image inspection apparatus that inspects a defect of an inspection object using an image obtained by imaging the inspection object, an illumination unit that irradiates the inspection object with light, and the illumination unit An imaging unit that captures an inspection object at a timing illuminated by the imaging unit to obtain a plurality of luminance images; an image generation unit that generates a plurality of inspection objects based on the plurality of luminance images captured by the imaging unit; An image selection unit that selects at least one first inspection image used for inspection from the plurality of inspection images generated by the image generation unit, and the first inspection selected by the image selection unit For the display unit capable of displaying an image for use and the first inspection image displayed on the display unit, designation of the position of the non-defect portion or defect portion of the inspection object in the first inspection image Accepted multiple times Based on a pixel value of a position information storage unit that stores position information of a plurality of non-defective portions or defective portions received by the receiving portion, and a position of the non-defective portions or defective portions received by the receiving portion A setting unit that automatically sets a pixel value range to be a non-defective part for the first inspection image displayed on the display unit, and the setting unit includes the image selection unit Thus, when an inspection image that is not displayed on the display unit is selected as a second inspection image, a plurality of pieces of position information indicating the position of the non-defect portion or the defect portion stored in the position information storage unit is obtained. The pixel value range to be determined as the non-defective part is updated by reading and referring to the pixel value corresponding to the position information in the second inspection image.

  According to this configuration, the first inspection image is displayed on the display unit. When the position of the non-defect portion or the defect portion of the inspection object is designated a plurality of times in the first inspection image, the pixel value range to be the non-defect portion is first based on the pixel value at the designated position. Since the inspection image is automatically set, the defective portion and the non-defective portion can be distinguished.

  After that, when the user selects an inspection image different from the first inspection image as the second inspection image to be used for the defect inspection, it corresponds to the position information indicating the position of the non-defect portion or the defect portion. With reference to the pixel value, the pixel value range to be a non-defective portion can be updated and automatically applied to the second inspection image.

  Further, the display unit is configured to be able to display a plurality of the inspection images, and the image generation unit is set by the setting unit for the plurality of inspection images displayed on the display unit. It is configured to generate a composite defect image in which a region included in all pixel value ranges that should be non-defective portions is a non-defective region and a region not included in any pixel value range is a defective region. it can.

  Further, the setting unit may be configured such that, after the second inspection image is selected by the image selection unit, an inspection image that is not displayed on the display unit is selected as a third inspection image. A plurality of position information indicating the position of the non-defect portion or the defect portion stored in the position information storage section is read out, and the pixel value corresponding to the position information in the third inspection image is referred to as the non-defect portion. The power pixel value range can be updated, and the third inspection image can be filtered.

  Further, the receiving unit receives a plurality of designations of the position of the non-defective part or the defective part of the inspection object in the second inspection image for the second inspection image displayed on the display unit. The position information storage unit is configured to store position information of a non-defective part or a defective part in the second inspection image received by the receiving unit, and the setting unit is configured to select the image selection unit. When the third inspection image is selected by the unit, position information indicating the position of the non-defect portion or the defective portion in the second inspection image stored in the position information storage unit is read, and the third inspection is performed. The pixel value range to be the non-defective part can be updated with reference to the pixel value corresponding to the position information in the image for use.

  In addition, when the third inspection image is selected by the image selection unit, the setting unit determines a position of a non-defective portion or a defective portion in the first inspection image stored in the position information storage unit. The position information indicating and the position information indicating the position of the non-defect portion or defect portion in the second inspection image are read, and the non-defect is referred to by referring to the pixel value corresponding to the position information in the third inspection image The pixel value range to be a part can be updated.

  According to the present invention, when an inspection image for use in inspection is displayed on the display unit from among a plurality of inspection images capable of detecting different types of defects, the inspection image is added or changed. In addition, it is possible to accurately perform defect inspection using the inspection image after addition or change, without requiring complicated setting work.

It is a figure which shows typically the operation state of the image inspection apparatus which concerns on Embodiment 1. FIG. 1 is a block diagram of an image inspection apparatus according to Embodiment 1. FIG. It is a front view of the light emission part of a pattern light illumination part. It is a figure which shows a 1st light emitting diode row | line | column. It is a figure which shows a 2nd light emitting diode row | line | column. It is a figure which shows the irradiation state of four types of Y direction pattern light which changed the phase of illumination intensity distribution every 90 degrees. It is a figure which shows the irradiation state of four types of X direction pattern light which changed the phase of illumination intensity distribution every 90 degrees. It is a figure which shows the positional relationship of an imaging part and pattern light illumination part in case a workpiece | work is a cylindrical member. It is a figure which shows the positional relationship of an imaging part and pattern light illumination part in case a workpiece | work is a member which has translucency. It is a figure which shows the interface for illumination installation method selection. It is a figure which shows the interface for camera up-down confirmation. It is a figure which shows the interface for camera attitude | position confirmation. It is a figure which shows the interface for a workpiece | work moving direction selection. It is a figure which shows the interface for illumination direction selection. It is a figure which shows the interface for cable pull-out direction selection. It is a figure which shows the 1st pattern light and 2nd pattern light irradiated when acquiring the positional relationship information of a light receiving element and a pattern light illumination part. It is a figure which shows the 1st image and 2nd image in case a pattern light illumination part is arrange | positioned so that a signal line may go out to the left direction. It is a figure which shows the 1st image and 2nd image in case a pattern light illumination part is arrange | positioned so that a signal line may go out upward. It is a figure which shows the 1st image and 2nd image in case a pattern light illumination part is arrange | positioned so that a signal line may go out below. It is a figure which shows the 1st image and 2nd image in case a pattern light illumination part is arrange | positioned so that a signal line may go out to the right direction. It is a figure explaining the point which acquires the positional relationship information of a light receiving element and a pattern light illumination part at the time of using an area camera. It is a figure which shows the imaging part and pattern light illumination part which concern on the other form of an information acquisition part. It is a figure which shows the interface for direction selection. It is a flowchart which shows the production | generation procedure of the image for a test | inspection. It is a figure which shows typically the production | generation procedure of the image for an inspection which applied the principle of deflectometry. It is a figure which shows the example of an actual luminance image. It is a figure which shows the concept of simple defect extraction typically. It is a figure which shows the interface for defect extraction. FIG. 26 is a view corresponding to FIG. 25 when a part of the inspection image is enlarged and displayed. FIG. 26 is a view corresponding to FIG. 25 in a case where a defective portion is forcibly extracted. It is a figure which shows the example which displayed the histogram and the pin at the time of threshold value setting. It is a figure which shows the example of the image for a test | inspection. It is a table | surface which shows the suitability of the filter with respect to each image for a test | inspection. It is a figure which shows the parameter setting interface of a filter process. It is a figure which shows the change of the image for a test | inspection before a filter process and after a filter process. It is a flowchart in the case of performing background selection a plurality of times. It is a figure which shows the example of the image for a test | inspection when the positional relationship of a pattern light illumination part and an imaging part is right and wrong. It is a time chart which shows the relationship between an imaging trigger signal and an illumination trigger signal, and an encoder pulse. It is a figure which shows a part of circuit structure of the current control part of a pattern light illumination part. It is a figure explaining the electric current value control method by an electric current control part. 6 is a block diagram of an image inspection apparatus according to Embodiment 2. FIG. FIG. 6 is a block diagram of an image inspection apparatus according to a third embodiment. It is a flowchart which shows the edge production | generation method. It is an image for a test | inspection which shows the state which put the pointer on the edge. It is an image for a test | inspection which shows the state which displayed the initial coordinate. It is a figure which shows typically the method of forming a segment and calculating | requiring an edge position. It is a figure which shows typically the method of projecting the pixel in a segment and calculating | requiring an edge position. It is a figure which shows the state which performed the connection process and specified the outline. It is a figure which shows the connection processing method when two outlines are approaching. It is a figure which shows another connection processing method when two outlines are approaching. It is a figure which shows the processing method when the curvature of an outline is small. It is a figure which shows the case where a test target object is a bead etc. FIG. It is a flowchart which shows the outline identification method of both sides. It is a figure which shows typically the method of calculating | requiring the control point P0 in the outline identification method of both sides. It is a figure which shows typically the method of forming a segment in the outline identification method of both sides, and calculating | requiring an edge position. FIG. 10 is a block diagram of an image inspection apparatus according to a fourth embodiment. It is a figure explaining the procedure which makes a part of workpiece | work the inspection object area | region. It is a figure explaining the procedure which makes almost the whole workpiece | work the inspection object area | region. It is a figure explaining the procedure which captures the image for a some partial test | inspection, and sets a test | inspection area | region. It is FIG. 2 equivalent view which concerns on the modification 1 of embodiment. It is FIG. 2 equivalent view which concerns on the modification 2 of embodiment. It is FIG. 2 equivalent figure which concerns on the modification 3 of embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

(Embodiment 1)
(Overall configuration of image inspection apparatus 1)
FIG. 1 schematically shows an operational state of an image inspection apparatus 1 according to an embodiment of the present invention. The image inspection apparatus 1 is configured to inspect defects of the workpiece W using an image obtained by imaging the workpiece W (inspection target) moving in one direction. Specifically, the image inspection apparatus 1 applies a plurality of pattern lights to the workpiece. Although it comprises at least a pattern light illumination unit 2 that executes pattern light illumination to irradiate W, an imaging unit 3, a control unit 4, a display unit 5, a keyboard 6, and a mouse 7, other than these Equipment can also be provided. For example, an external control device 8 composed of a programmable logic controller (PLC) or the like is connected to the control unit 4. The external control device 8 may constitute a part of the image inspection apparatus 1. The external control device 8 may not be a component of the image inspection apparatus 1.

  FIG. 1 shows a case where a plurality of workpieces W are conveyed in the direction indicated by the white arrow in FIG. 1 in a state where they are placed on the upper surface of the conveyor belt B for conveyance. The workpiece W is an inspection object. The external control device 8 is a device for controlling the conveyor belt conveyor B and the image inspection apparatus 1 in sequence, and a general-purpose PLC can be used.

  In the description of this embodiment, the transfer direction of the workpiece W by the transfer belt conveyor B (the movement direction of the workpiece W) is the Y direction, and the direction orthogonal to the Y direction in plan view of the transfer belt conveyor B is the X direction. The direction perpendicular to the X direction and the Y direction (the direction perpendicular to the upper surface of the conveyor belt B for conveyance) is defined as the Z direction, but this is only defined for convenience of explanation.

  The image inspection apparatus 1 can be used for appearance inspection of the workpiece W, that is, when inspecting the surface of the workpiece W for defects such as scratches, dirt, and dents. During operation, the image inspection apparatus 1 receives an inspection start trigger signal that defines the start timing of defect inspection from the external control device 8 via a signal line. The image inspection apparatus 1 captures and illuminates the workpiece W based on the inspection start trigger signal, and obtains an inspection image after predetermined processing. Thereafter, the inspection result is transmitted to the external control device 8 through the signal line. As described above, when the image inspection apparatus 1 is operated, the input of the inspection start trigger signal and the output of the inspection result are repeatedly performed between the image inspection apparatus 1 and the external control device 8 through the signal line. Note that the inspection start trigger signal and the inspection result may be input via the signal line between the image inspection apparatus 1 and the external control device 8 as described above, or other signals (not shown). It may be done via a line. For example, a sensor for detecting the arrival of the workpiece W and the image inspection apparatus 1 may be directly connected, and an inspection start trigger signal may be input from the sensor to the image inspection apparatus 1.

  The image inspection apparatus 1 may be configured by dedicated hardware, or may be configured by installing software in a general-purpose device, for example, by installing an image inspection program in a general-purpose or dedicated computer. In the following example, a case in which an image inspection program is installed in a dedicated computer that specializes hardware such as a graphic board for image inspection processing will be described.

(Configuration of pattern light illumination unit 2)
The pattern light illumination unit 2 is for irradiating the workpiece W with pattern light having a periodic illuminance distribution. For example, a plurality of light emitting diodes, liquid crystal panels, organic EL panels, digital micromirror devices (DMD), etc. It can be configured and can also be simply referred to as an illumination unit. Although a liquid crystal panel, an organic EL panel, and a DMD are not shown, those having a conventionally known structure can be used. The pattern light illumination unit 2 is connected to the control unit 4 via a signal line 100a, and can be installed apart from the imaging unit 3 and the control unit 4.

  In the case where a plurality of light emitting diodes are used for the pattern light illuminating unit 2, it is possible to generate a pattern light having a periodic illuminance distribution by arranging a plurality of light emitting diodes in a dot matrix and controlling the current value. In the case of a liquid crystal panel and an organic EL panel, by controlling each panel, the light emitted from each panel can be a pattern light having a periodic illuminance distribution. In the case of a digital micromirror device, pattern light having a periodic illuminance distribution can be generated and irradiated by controlling a built-in micromirror surface. In addition, the structure of the pattern light illumination part 2 is not restricted to what was mentioned above, If it is an apparatus, an apparatus, etc. which can produce | generate the pattern light which has periodic illumination intensity distribution, it can be used.

  Hereinafter, the case where a plurality of light emitting diodes are used in the pattern light illumination unit 2 will be described in detail. In this case, the pattern light illumination unit 2 emits light from the light emitting unit 23 (shown in FIG. 3) in which a plurality of light emitting diodes 20 and 21 arranged in a two-dimensional manner are mounted on the substrate 23a, and the light emitting diodes 20 and 21. A diffusing member 24 (shown in FIGS. 1, 5A, and 5B) for diffusing the emitted light is provided. The light emitting unit 23 has a substantially rectangular shape as a whole. The light emitting surface of the light emitting unit 23 includes a virtual dividing line J1 extending in the Y direction through the central portion in the X direction of the light emitting unit 23, and a virtual dividing line extending in the X direction through the central portion in the Y direction of the light emitting unit 23. J2 can be virtually divided into first to fourth regions S1 to S4. The first to fourth regions S1 to S4 are all substantially rectangular with the same size. Each region S1 to S4 can also be called a block, and one block is composed of 12 LEDs × 12 rows × 2 directions.

  In the first region S1, as shown in FIG. 4A, twelve first light-emitting diode rows A1 to A12 including a plurality of light-emitting diodes 20 arranged in series at equal intervals in the Y direction, As shown in 4B, 12 rows of second light emitting diode rows B1 to B12 made up of a plurality of light emitting diodes 21 arranged in series at equal intervals in the X direction are formed. As shown in FIG. 3, the arrangement direction of the first light emitting diode rows A1 to A12 in the first region S1 is the X direction, and they are arranged in parallel to each other. Electric power is individually supplied to each of the first light emitting diode rows A1 to A12.

  As shown in FIG. 3, the arrangement direction of the second light emitting diode rows B1 to B12 in the first region S1 is the Y direction, and they are arranged in parallel to each other. Electric power is individually supplied to each of the second light emitting diode rows B1 to B12.

  The first light emitting diode rows A1 to A12 and the second light emitting diode rows B1 to B12 are arranged so as to cross each other in the first region S1. The light emitting diodes 20 constituting the first light emitting diode rows A1 to A12 and the light emitting diodes 21 constituting the second light emitting diode rows B1 to B12 are arranged so as not to overlap in the light irradiation direction. As a result, the plurality of light emitting diodes 20 and 21 are arranged in a dot matrix in the first region S1.

  Since twelve light emitting diodes 20 and 21 are connected in series to form each column A1 to A12 and B1 to B12, a control line is provided in each column without providing a control line for each light emitting diode 20 and 21. One set is enough. Similarly to the first region S1, the first light emitting diode rows A1 to A12 and the second light emitting diode rows B1 to B12 intersect each other in the second region S2, the third region S3, and the fourth region S4. Is arranged. That is, in this embodiment, while increasing the number of the light emitting diodes 20 and 21 and arranging the light sources of the light emitting unit 23 densely, the light emitting diode rows to be controlled are the first light emitting diode rows A1 to A1 in the first region S1. A12 and the second light emitting diode rows B1 to B12, the first light emitting diode rows A1 to A12 and the second light emitting diode rows B1 to B12 in the second region S2, the first light emitting diode rows A1 to A12 in the third region S3, and The total of 96 columns (12 columns × 2 × 4 regions) of the second light emitting diode columns B1 to B12 and the first light emitting diode columns A1 to A12 and the second light emitting diode columns B1 to B12 in the fourth region S4 are sufficient. .

  The second light emitting diode rows B1 to B12 in the first region S1 and the second light emitting diode rows B1 to B12 in the second region S2 are arranged so as to be aligned on the same straight line extending in the X direction. The second light emitting diode rows B1 to B12 in the third region S3 and the second light emitting diode rows B1 to B12 in the fourth region S4 are arranged so as to be aligned on the same straight line extending in the X direction.

  The first light emitting diode rows A1 to A12 in the first region S1 and the first light emitting diode rows A1 to A12 in the third region S2 are arranged so as to be aligned on the same straight line extending in the Y direction. . The first light emitting diode rows A1 to A12 in the second region S2 and the first light emitting diode rows A1 to A12 in the fourth region S4 are arranged so as to be aligned on the same straight line extending in the Y direction.

  The diffusion member 24 shown in FIG. 5A, FIG. 5B, and the like is made of a translucent plate material arranged so as to cover all of the light emitting diodes 20 and 21 in the first to fourth regions S1 to S4. As the plate material constituting the diffusing member 24, a known material can be used, and incident light can be diffused and emitted.

  By individually controlling the current values passed through the first light emitting diode rows A1 to A12 and the second light emitting diode rows B1 to B12 in the first to fourth regions S1 to S4, the illuminance is increased in the Y direction as shown in FIG. 5A. It is possible to generate Y direction pattern light with uniform illuminance in the X direction and X direction pattern light with uniform illuminance in the Y direction as shown in FIG. 5B. . Since the light emitting diodes 20 and 21 are arranged in a dot matrix as described above, the light source is arranged in a dot shape in the light emitting unit 23, but each light emitting diode is provided by providing the diffusing member 24. The light of 20, 21 is diffused and applied to the outside, and as shown in each figure, when viewed from the outside, the pattern light with the illuminance gradually changed can be obtained.

  The light emitting diodes 20 and 21 may be controlled by, for example, PWM control or current value control (current value control), and current value control is particularly preferable. By controlling the current value, it is possible to realize a quick change in illuminance that fully utilizes the speed of response of the light emitting diodes 20 and 21. For example, a time interval for switching one pattern light to another pattern light is 2 μm. The interval can be as short as 2 seconds.

  In addition, it is also possible to irradiate light having a uniform illuminance distribution in the plane by flowing currents having the same current value through all the light emitting diodes 20 and 21. If the current values passed through all the light emitting diodes 20 and 21 are changed to be the same, the light emission state can be changed from a dark surface light emission state to a bright surface light emission state.

  In the case of the Y-direction pattern light shown in FIG. 5A, since the brightness changes in the Y direction, it can also be expressed as pattern light in which the stripe pattern is repeated in the Y direction. When generating the Y direction pattern light, a plurality of Y direction pattern lights having different illuminance distribution phases can be generated by shifting the phase of the illuminance distribution in the Y direction. The illuminance distribution of the Y direction pattern light can also be represented by a waveform that approximates a sine waveform. In this case, for example, the phase is changed by 90 °, the Y direction pattern light at 0 °, and the Y direction at 90 °. Pattern light, Y direction pattern light at 180 °, and Y direction pattern light at 270 ° can be generated.

  Further, in the case of the X direction pattern light shown in FIG. 5B, since the brightness changes in the X direction, it can also be expressed as a pattern light in which the stripe pattern is repeated in the X direction. When generating the X direction pattern light, by shifting the phase of the illuminance distribution in the X direction, a plurality of X direction pattern lights having different illuminance distribution phases can be generated. The illuminance distribution of the X direction pattern light can also be represented by a waveform approximating a sin waveform. In this case, for example, the phase is changed by 90 ° to change the X direction pattern light at 0 °, and the X direction at 90 °. Pattern light, X direction pattern light at 180 °, and X direction pattern light at 270 ° can be generated. That is, the pattern light illumination unit 2 can illuminate the workpiece W in different illumination modes.

  When performing a later-described deflectometry process, the pattern light applied to the workpiece W can be not only a sin waveform but also a pattern light such as a triangular wave.

  Further, the length of one side of the light emitting unit 23 can be set to 100 mm, for example. Inside the 100 mm square, 24 light emitting diodes 20 and 21 are arranged 24 in length and 24 in width. By controlling the current value of the light emitting diodes 20 and 21, pattern light with high gradation and high gradation can be generated. The length of one side of the light emitting unit 23, the number of light emitting diodes 20 and 21, the number of columns, and the number of regions of the light emitting unit 23 are merely examples, and are not particularly limited. When the illuminance distribution of the pattern light can be represented by a waveform that approximates a sin waveform, the length of one side of the light emitting unit 23 can be set to one wavelength of the sin waveform.

(Configuration of the imaging unit 3)
As shown in FIG. 2, the imaging unit 3 includes a plurality of light receiving elements 3a arranged in a line, and the direction in which the light receiving elements 3a are arranged is orthogonal to the moving direction (Y direction) of the workpiece W (X direction). ) And a condensing optical system 32. The light receiving element 3a is an image sensor composed of an imaging element such as a CCD (charge-coupled device) or a CMOS (complementary metal oxide semiconductor) that converts the intensity of light obtained through the condensing system optical system 32 into an electric signal. The condensing system optical system 32 is an optical system for condensing light incident from the outside, and typically includes one or more optical lenses.

  The imaging unit 3 is connected to the control unit 4 via a signal line 100 b different from the signal line 100 a of the pattern light illumination unit 2, and is installed away from the pattern light illumination unit 2 and the control unit 4. Be able to. That is, the imaging unit 3 is configured to be installed independently of the pattern light illumination unit 2. The signal line 100 b of the imaging unit 3 may be branched from the signal line 100 a of the pattern light illumination unit 2.

  An imaging trigger signal transmitted from the control unit 41 of the control unit 4 is input to the imaging unit 3 via the signal line 100b. The imaging unit 3 is configured to perform imaging every time an imaging trigger signal is received. The imaging trigger signal will be described later.

  As shown in FIG. 1, in the case of a planar work W, the pattern light irradiated from the pattern light illumination unit 2 toward the surface of the work W is reflected by the surface of the work W and the light collecting system of the imaging unit 3. The positional relationship between the imaging unit 3 and the pattern light illumination unit 2 can be set so as to enter the optical system 32.

  As shown in FIG. 6A, even when the workpiece W is a cylindrical member, the pattern light irradiated from the pattern light illumination unit 2 toward the surface of the workpiece W is reflected by the surface of the workpiece W. The positional relationship between the imaging unit 3 and the pattern light illumination unit 2 can be set so as to be incident on the condensing system optical system 32 of the imaging unit 3.

  In addition, as shown in FIG. 6B, when the workpiece W is a transparent member such as a transparent film or sheet, the pattern light irradiated from the pattern light illumination unit 2 toward the surface of the workpiece W is the workpiece W. The positional relationship between the imaging unit 3 and the pattern light illumination unit 2 can be set so that the light passes through W and enters the condensing optical system 32 of the imaging unit 3.

  In any of the above cases, the pattern light illumination unit 2 and the imaging unit 3 are arranged so that the regular reflection component reflected by the surface of the workpiece W is incident on the condensing optical system 32 of the imaging unit 3.

  The positional relationship between the imaging unit 3 and the pattern light illuminating unit 2 shown in FIG. 1 and the positional relationship between the imaging unit 3 and the pattern light illuminating unit 2 shown in FIG. The light receiving element 3a of the line camera 31 receives the pattern light reflected by the reflected light receiving positional relationship.

  On the other hand, the positional relationship between the imaging unit 3 and the pattern light illumination unit 2 shown in FIG. 6B is such that the light receiving element 3a of the line camera 31 receives the pattern light irradiated from the pattern light illumination unit 2 and transmitted through the inspection object. This is the positional relationship of light reception. In this case, the number of pattern light reflections is zero.

  The number of reflections of the pattern light is one in the positional relationship of the reflected light reception, and the number of reflections of the pattern light is zero in the positional relationship of the transmitted light reception. Further, instead of the line camera 31, an area camera (a camera in which the light receiving elements are arranged in the X direction and the Y direction) can be used for the imaging unit 3. In the case of this area camera, a form of coaxial illumination is also possible. Is possible. In this case, since reflection by a half mirror is added to the reflected light installation, the number of reflections is two. By allowing the user to input the number of times the pattern light is reflected, it is possible to determine whether or not the reflected light is in a positional relationship and whether or not the transmitted light is in a positional relationship.

  As shown in FIG. 2, the imaging unit 3 is provided with an LED pointer 34. The LED pointer 34 is for irradiating the pointer light in the axial direction of the condensing system optical system 32 and is configured to be switched between an irradiation state and a non-irradiation state by a control signal from the control unit 4. ing. As an example of the irradiation form of the pointer light, for example, as shown in FIG. 8, a form for confirming the vertical direction of the line camera 31 can be used. In FIG. 8, pointer light is irradiated to the upper side and the lower side of the line camera 31, respectively, and the upper side is continuously lit and the lower side is blinked. The pointer light may have any form. For example, a character or the like may be used as the pointer light. The direction perpendicular to the arrangement direction of the light receiving elements 3 a when the line camera 31 is viewed from the light receiving side can be set as the vertical direction of the line camera 31.

  As shown in FIG. 2, the imaging unit 3 is provided with a gravitational acceleration sensor 35 that detects gravitational acceleration. The gravitational acceleration sensor 35 grasps the posture of the imaging unit 3 (an angle formed between the axial direction of the condensing optical system 32 and the horizontal plane, an angle formed between the axial direction of the condensing optical system 32 and the vertical plane, etc.). By using the output value of the gravitational acceleration sensor 35, the posture of the imaging unit 3 can be obtained almost in real time according to a conventionally known method.

(Configuration of display unit 5)
The display part 5 consists of an organic EL display, a liquid crystal display, etc., for example. The display unit 5 is connected to the control unit 4. For example, the image captured by the imaging unit 3, various images generated based on the image captured by the imaging unit 3, the defect inspection result of the workpiece W, and an operation interface It is configured so that various setting interfaces, setting values, and the like can be displayed. The display unit 5 can also display a plurality of inspection images and the like at a time.

  By using the display unit 5 as a touch panel, the display unit 5 can have various information input functions.

(Configuration of keyboard 6 and mouse 7)
The keyboard 6 and the mouse 7 are conventionally well-known devices for computer operation, and are connected to an input information receiving unit 44 (shown in FIG. 2) of the control unit 4. Various information can be input to the control unit 4 by operating the keyboard 6 or the mouse 7, and an image or the like displayed on the display unit 5 can be selected.

  Specifically, by operating the keyboard 6 or the mouse 7, movement direction information regarding the moving direction of the workpiece W with respect to the arrangement direction of the light receiving elements 3 a of the line camera 31, the light receiving elements 3 a of the line camera 31, and the pattern light illumination unit 2 When the positional relationship information regarding the positional relationship is input to the input information receiving unit 44, the input information receiving unit 44 can receive the input movement direction information and positional relationship information. The keyboard 6, the mouse 7, and the input information reception unit 44 are the information acquisition unit 9 of the present invention.

  The moving direction information is the moving direction of the workpiece W illustrated in FIG. 1 and can be either the direction of a white arrow or the direction opposite to the white arrow. The movement direction information includes the vertical direction of the line camera 31 and the movement direction of the workpiece W when the direction perpendicular to the arrangement direction of the light receiving elements 3a when the line camera 31 is viewed from the light receiving side is defined as the vertical direction of the line camera 31. Can be included. The positional relationship information includes the above-described positional relationship of reflected light reception and the positional relationship of transmitted light reception.

  In addition, instead of the keyboard 6 and the mouse 7, or in addition to the keyboard 6 and the mouse 7, for example, a computer input device such as a voice input device or a touch operation panel can be used.

(Configuration of control unit 4)
The control unit 4 is a unit for controlling each part of the image inspection apparatus 1 and can be constituted by a CPU, MPU, system LSI, DSP, dedicated hardware, or the like. The control unit 4 is equipped with various functions as will be described later, but these may be realized by a logic circuit or may be realized by executing software.

  As shown in FIG. 2, the control unit 4 includes a filter processing unit 40, a control unit 41, an image generation unit 42, a UI generation unit 43, an input information reception unit 44, an image analysis unit 45, and an operation reception. A unit 46, a display control unit 47, a position designation receiving unit 48, and a setting unit 49. A storage device 10 is connected to the control unit 4. The storage device 10 can be a part of the components of the image inspection device 1 or can be a device different from the image inspection device 1. The storage device 10 can be composed of a semiconductor memory, a hard disk, or the like. The storage device 10 can also be provided with a reading device that can read information stored in various storage media such as a CD-ROM and a DVD-ROM.

(Configuration of UI generation unit 43)
The UI generation unit 43 is a part for generating various interfaces to be displayed on the display unit 5, and the various interfaces generated by the UI generation unit 43 are output from the control unit 4 to the display unit 5 to be displayed on the display unit 5. Is displayed.

  The interfaces generated by the UI generation unit 43 include, for example, an illumination installation method selection interface 50 shown in FIG. 7, a camera up / down confirmation interface 51 shown in FIG. 8, a camera posture confirmation interface 52 shown in FIG. There is a work movement direction selection interface 53 and an illumination direction selection interface 54 shown in FIG. The interfaces 50 to 54 are displayed on the display unit 5 when the image inspection apparatus 1 is set before the image inspection apparatus 1 is operated.

  The illumination installation method selection interface 50 shown in FIG. 7 is an interface for inputting positional relationship information between the light receiving element 3a of the line camera 31 and the pattern light illumination unit 2, and the light receiving element 3a, the pattern light illumination unit 2, and the like. The positional relationship between the reflected light reception and the transmitted light reception positional relationship can be input. The illumination installation method selection interface 50 displays a reflected light installation illustration 50a for schematically showing the positional relationship of reflected light reception and a transmitted light installation illustration 50b for schematically showing the positional relationship of transmitted light reception. Has been. The user looks at the reflected light installation illustration 50a and the transmitted light installation illustration 50b displayed on the display unit 5, and has the same positional relationship between the light receiving element 3a installed at the actual site and the pattern light illumination unit 2. Since it is sufficient to select an illustration in a positional relationship with the mouse 7 or the like, input errors are less likely to occur. As for the input operation of the user, the input content is received by the input information receiving unit 44. Thereby, positional relationship information can be input easily and without error.

  The camera up / down confirmation interface 51 shown in FIG. 8 is an interface for confirming the up / down direction of the line camera 31. When the pointer light is irradiated from the LED pointer 34 of the imaging unit 3, the illustration 50a including the pointer light is displayed so that the user can know that the blinking side is the lower side of the line camera 31. Yes. In addition, the text indicates which side is the lower side of the line camera 31.

  9 is also an interface for confirming the vertical direction of the line camera 31. The camera posture confirmation interface 52 incorporates a posture display area 52 a that schematically displays the current posture of the imaging unit 3 obtained by the gravitational acceleration sensor 35 of the imaging unit 3. The posture display area 52a includes a rear view 52b showing an inclination with respect to a horizontal plane when the imaging unit 3 is viewed from the back, a side view 52c showing an inclination with respect to a vertical plane when the imaging unit 3 is viewed from the side, and an imaging unit. A top view 52d showing a posture when 3 is viewed from above is displayed. The user can check the vertical direction of the line camera 31 by looking at the respective figures 52b, 52c, and 52d displayed in the posture display area 52a.

  A workpiece movement direction selection interface 53 shown in FIG. 10 is an interface for selecting and inputting the movement direction of the workpiece W. A camera up / down confirmation interface 51 shown in FIG. 8 can be incorporated in the work movement direction selection interface 53. The workpiece movement direction selection interface 53 includes an upward movement illustration 53a showing a state in which the workpiece W moves from the lower side (bottom surface side) to the upper side of the line camera 31, and from the upper side to the lower side of the line camera 31. A downward movement illustration 53b showing how the workpiece W moves is displayed. The user looks at the camera vertical confirmation interface 51 displayed on the display unit 5 to grasp the vertical direction of the line camera 31, and then looks at the upward movement illustration 53a and the downward movement illustration 53b to work. The moving direction of W with respect to the line camera 31 can be selected and input.

  The illumination direction selection interface 54 shown in FIG. 11 is an interface for selecting and inputting the positional relationship between the line camera 31 and the pattern light illumination unit 2. The illumination direction selection interface 54 can be displayed on the assumption that the user knows the direction of the line camera 31 (whether it is the upper side or the lower side). The direction of the section 2 is configured so that it can be selected from a plurality of illustrations.

  That is, the illumination direction selection interface 54 includes the first illustration 54a showing the state in which the pattern light illumination unit 2 is arranged so that the signal line 100a protrudes to the left side with respect to the line camera 31, and the pattern light illumination unit 2. The second illustration 54b showing a state in which the signal line 100a is arranged so as to protrude upward with respect to the line camera 31, and the pattern light illumination unit 2 are arranged so that the signal line 100a protrudes downward with respect to the line camera 31. A third illustration 54c showing the state of the pattern light and a fourth illustration 54d showing the state where the pattern light illumination unit 2 is arranged so that the signal line 100a protrudes to the right side with respect to the line camera 31 are displayed. The user looks at the first to fourth illustrations 54a to 54d displayed on the display unit 5, and selects the positional relationship between the line camera 31 and the pattern light illumination unit 2 installed at the actual site. Can be entered.

  The interface generated by the UI generation unit 43 can include a cable drawing direction selection interface 55 shown in FIG. “Cable” refers to the signal line 100 a connected to the pattern light illumination unit 2. The cable drawing direction selection interface 55 can be configured to include a so-called pull-down menu button. This cable drawing direction selection interface 55 can be displayed on the premise that the user knows the direction of the line camera 31 (whether the upper side or the lower side). It is comprised so that the direction of the light illumination part 2 can be selected from several choices.

  That is, the pull-down menu 55a of the cable drawing direction selection interface 55 includes four options of “reference direction”, “90 ° clockwise”, “180 ° clockwise”, and “270 ° clockwise”. (In FIG. 12, only the “reference direction” is displayed). Here, the “reference direction” refers to a state in which the pattern light illumination unit 2 is arranged so that the signal line 100a comes out in the direction (left direction) shown in the first illustration 54a of the illumination direction selection interface 54 shown in FIG. It is an option to select when. “90 ° clockwise” is an option to be selected when the pattern light illumination unit 2 is arranged so that the signal line 100a comes out upward. “Clockwise 180 °” is an option selected when the pattern light illumination unit 2 is arranged so that the signal line 100a comes out in the right direction. “270 ° clockwise” is an option to be selected when the pattern light illumination unit 2 is arranged so that the signal line 100a comes out downward. The expression of each option is an example, and is not limited to the above expression.

(Configuration of the image analysis unit 45)
The image analysis unit 45 illustrated in FIG. 2 acquires positional relationship information regarding the positional relationship between the light receiving element 3a of the line camera 31 and the pattern light illumination unit 2 by analyzing a plurality of images captured by the imaging unit 3. And can be a part of the information acquisition unit 9.

  Specifically, the image analysis unit 45 sets the first pattern having a periodic illuminance distribution in one direction as a first step when setting the image inspection apparatus 1 before the image inspection apparatus 1 is operated. Generating a first image obtained by imaging an irradiation surface irradiated with light, and a second image obtained by imaging the irradiation surface irradiated with a second pattern light having a periodic illuminance distribution in a direction orthogonal to the one direction. In addition, the pattern light illumination unit 2 and the imaging unit 3 are controlled. The irradiation surface may be a workpiece W or another member.

  The first pattern light in the first step can be X-direction pattern light whose illuminance changes in the X direction as shown on the left side of FIG. 13, and is set as pattern light that becomes darker toward the right side of FIG. The second pattern light can be a Y-direction pattern light whose illuminance changes in the Y direction as shown on the right side of FIG. 13 and is a pattern light that becomes darker toward the lower side of FIG.

  First, the X-direction pattern light on the left side of FIG. 13 is irradiated on an arbitrary irradiation surface, and the irradiation surface irradiated with the X-direction pattern light is imaged by the imaging unit 3 to obtain a first image. Assume that the first image is an image with a gradation that becomes darker toward the right as shown in FIG. Thereafter, the Y-direction pattern light on the right side of FIG. 13 is irradiated on an arbitrary irradiation surface, and the irradiation surface irradiated with the Y-direction pattern light is imaged by the imaging unit 3 to obtain a second image. Assume that the second image is an image without gradation as shown in FIG. Since the arrangement direction of the light receiving elements 3a is the X direction, when the first image and the second image shown in FIG. 14 are obtained, the signal line 100a comes out to the left as shown in the lower side of FIG. It can be estimated that the pattern light illumination unit 2 is arranged. This relationship may be defined in advance.

  As shown in FIG. 15, when the first image is an image without gradation and the second image is an image with gradation that becomes darker toward the right side, as shown in the lower side of FIG. It can be estimated that the pattern light illumination unit 2 is arranged so as to come out upward.

  As shown in FIG. 16, when the first image is an image without gradation and the second image is an image with gradation that becomes darker toward the left side, as shown in the lower side of FIG. It can be estimated that the pattern light illumination unit 2 is arranged so as to come out downward.

  As shown in FIG. 17, when the first image is a gradation image that becomes darker toward the left side and the second image is an image without gradation, a signal line 100a is displayed as shown in the lower side of FIG. It can be estimated that the pattern light illumination unit 2 is arranged so as to come out in the right direction.

  That is, the image analysis unit 45 performs a step of analyzing the first image and the second image captured by the imaging unit 3, and as a result, the first image and the second image are images with gradation or no gradation. Information on the positional relationship between the light receiving element 3a and the pattern light illuminating unit 2 is obtained by obtaining which side is darker (or brighter) in the case of an image with gradation by obtaining whether it is an image. Can be obtained.

  Further, instead of the line camera 31, an area camera (a camera in which light receiving elements are arranged in the X direction and the Y direction) can be used for the imaging unit 3. In the case of this area camera, the image analysis unit 45 can acquire the positional relationship information between the area camera and the pattern light illumination unit 2 by analyzing one image captured by the imaging unit 3.

  Specifically, as shown in FIG. 18A, an imaging surface is irradiated with the pattern light by irradiating an arbitrary irradiation surface with pattern light capable of displaying the alphabet “R” from the pattern light illumination unit 2. 3 to take an image. As a result, when the “R” image described at the top of FIG. 18 is obtained, it can be estimated that the pattern light illumination unit 2 is arranged so that the signal line 100a is leftward. When the image of “R” described second from the top in FIG. 18 is obtained, it can be estimated that the pattern light illumination unit 2 is arranged so that the signal line 100a comes out upward. When the “R” image described third from the top in FIG. 18 is obtained, it can be estimated that the pattern light illumination unit 2 is arranged so that the signal line 100a comes to the right. When the image of “R” described at the bottom of FIG. 18 is obtained, it can be estimated that the pattern light illumination unit 2 is arranged so that the signal line 100a protrudes downward. The pattern light may indicate other than “R”, and may be, for example, a character, a symbol, a figure, a combination thereof, or the like.

(Other forms of information acquisition unit)
As shown in FIG. 19, a predetermined mark 3 c is provided in the imaging unit 3, and the left side symbol A, the lower side symbol B, the right side symbol C, and the upper side symbol D indicating the four directions are respectively displayed on the pattern light illumination unit 2. Prepare it. The UI generation unit 43 generates a direction selection interface 56 shown in FIG. The generated direction selection interface 56 is displayed on the display unit 5. The direction selection interface 56 is provided with a pull-down menu 56a for selecting a left symbol A, a lower symbol B, a right symbol C, and an upper symbol D.

  The user visually confirms which side of the pattern light illumination unit 2 the mark 3c of the imaging unit 3 is located on, and then points to the mark 3c of the imaging unit 3 from the pull-down menu 56a of the direction selection interface 56. Select the symbols A to D in the direction. Thereby, positional relationship information between the light receiving element 3a of the line camera 31 and the pattern light illumination unit 2 can be input.

(Warning function)
By using the illumination direction selection interface of FIG. 11, the cable drawing direction selection interface of FIG. 12, and the direction selection interface of FIG. 20, the user can obtain positional relationship information between the light receiving element 3a and the pattern light illumination unit 2. Can be entered. However, there is a case where the user makes an input operation mistakenly, or the vertical direction of the line camera 31 is recognized in the first place, and the user's input result is different from the actual installation state.

  In contrast, the image inspection apparatus 1 can be provided with a warning function. The alerting function uses the illumination direction selection interface shown in FIG. 11, the cable drawing direction selection interface shown in FIG. 12, and the direction selection interface shown in FIG. 20 to allow the user to position the light receiving element 3 a and the pattern light illumination unit 2. After inputting the relationship information, the analysis shown in FIGS. 13 to 17 is performed, or in the case of an area camera, the analysis shown in FIG. 18 is performed, so that the input positional relationship information matches the actual installation status. If the input positional relationship information does not match the actual installation status, for example, a message is displayed on the display unit 5 to prompt the user to confirm and input again. It is a function.

(Configuration of control unit 41)
A control unit 41 illustrated in FIG. 2 is an imaging control unit for controlling the pattern light illumination unit 2 and the imaging unit 3. Specifically, a plurality of pattern lights in which the phase of the illuminance distribution is shifted in at least one direction of the arrangement direction of the light receiving elements 3a and the movement direction of the workpiece W are generated and sequentially irradiated onto the workpiece W. The pattern light illumination unit 2 and the imaging unit 3 are controlled so that a plurality of luminance images are obtained by capturing an area including at least the pattern light irradiation surface of the workpiece W at the timing of the above. When obtaining a plurality of luminance images, both the illumination conditions of the pattern light illumination unit 2 and the imaging conditions of the imaging unit 3 may be changed, or only one of them may be changed.

  The illumination conditions of the pattern light illumination unit 2 can include, for example, the type of pattern light to be generated, the order of generation of pattern light when generating a plurality of pattern lights, the brightness of the pattern light (light intensity), and the like. . As the types of pattern light to be generated, for example, at least four Y-direction pattern lights shown in FIG. 5A and four X-direction pattern lights shown in FIG. 5B can be included. Can be included. The pattern light is generated in the order of Y direction pattern light at 0 °, Y direction pattern light at 90 °, Y direction pattern light at 180 °, and Y direction at 270 ° shown in FIG. 5A. 5B, the X direction pattern light in the case of 0 °, the X direction pattern light in the case of 90 °, the X direction pattern light in the case of 180 °, and the X direction pattern in the case of 270 °. Can be light.

  The illumination conditions of the pattern light illumination unit 2 can be stored in the illumination condition storage unit 10 a provided in the storage device 10. Further, the pattern light illumination unit 2 can incorporate a computing device (field programmable gate array: FPGA) 2 a having an illumination condition storage unit 2 b capable of storing the illumination conditions of the pattern light illumination unit 2. The present invention is not limited to the FPGA, and a calculation unit other than the FPGA and the illumination condition storage unit 2b can be incorporated.

  The imaging conditions of the imaging unit 3 include, for example, at least one of a gain at the time of imaging and an exposure time (shutter speed). The control unit 41 can arbitrarily change the gain and exposure time of the imaging unit 3, and the imaging unit 3 executes imaging with the gain and exposure time set by the control unit 41.

(Trigger signal transmission)
The control unit 41 is configured to receive an encoder pulse signal when the encoder pulse signal is input from the outside. The encoder pulse signal is, for example, a pulse signal generated outside the control unit 41, such as a pulse signal output from a rotary encoder provided on the rotating shaft of the conveyor belt B for conveyance, a pulse signal output from the external control device 8, or the like. It is.

  The control unit 4 has a trigger signal transmission unit 4b. The trigger signal transmission unit 4 b may constitute a part of the control unit 41 or may be configured separately from the control unit 41. When the control unit 41 receives one encoder pulse signal from the outside, a trigger is generated so that a plurality of luminance images are generated by changing at least one of the illumination conditions of the pattern light illumination unit 2 and the imaging conditions of the imaging unit 3. The signal transmission unit 4 b is configured to sequentially transmit a plurality of imaging trigger signals to the imaging unit 3 and to transmit a plurality of illumination trigger signals to the pattern light illumination unit 2. A plurality of imaging trigger signals can be sequentially transmitted only to the imaging unit 3.

  In this embodiment, as described above, since the pattern light illumination unit 2 sequentially emits eight types of pattern light, as shown in FIG. 35, the trigger signal transmission unit 4b receives one encoder pulse signal EP1 from the outside. Is received, the imaging trigger signal is transmitted eight times (C1 to C8). Thereafter, when the encoder pulse signal EP2 is received, the imaging trigger signal is similarly transmitted eight times.

  The trigger signal transmission unit 4b is configured to sequentially transmit a plurality of illumination trigger signals to the pattern light illumination unit 2 in synchronization with the imaging trigger signal when receiving one encoder pulse signal from the outside. Yes. Since it is necessary to sequentially irradiate the pattern light illumination unit 2 with eight types of pattern light, when the trigger signal transmission unit 4b receives one encoder pulse signal EP1 from the outside, the illumination light trigger signal is transmitted eight times (L1). ~ L8) Transmit. Thereafter, when the encoder pulse signal EP2 is received, the illumination trigger signal is similarly transmitted eight times.

  In addition, when receiving one encoder pulse signal from the outside, the control unit 41 can also be configured to sequentially transmit a plurality of imaging trigger signals to the imaging unit 3 in synchronization with the illumination trigger signal.

(Generation of pattern light by the pattern light illumination unit)
The pattern light illuminator 2 generates a plurality of pattern lights by controlling the value of the current passed through the light emitting diodes 20 and 21 based on the illumination trigger signal transmitted from the trigger signal transmitter 4b. Since the pattern light has a periodic illuminance distribution, the current value to be passed through each of the light emitting diodes 20 and 21 is set according to the generated pattern light so that the illuminance distribution can be obtained. The value of the current passed through each light emitting diode 20, 21 corresponds to the illumination condition, and can be stored in the illumination condition storage unit 10 a of the storage device 10.

  The illumination condition can be illumination setting data including illumination timing information (lighting time, lighting interval), illumination intensity information, and illumination pattern information of the light emitting diodes 20 and 21 of the pattern light illumination unit 2. Any of the illumination setting data can display a user interface for illumination setting on the display unit 5 and accept adjustment by the user.

  The lighting timing information includes a lighting time during which the light-emitting diodes 20 and 21 are turned on after receiving the illumination trigger signal, and the light-emitting diodes 20 and 21 that are lighted first when the light-emitting diodes 20 and 21 are turned on. And the lighting interval (interval) from when the LED is turned off until the next light emitting diode 20 or 21 is turned on. Further, the illumination intensity information is information indicating the illumination intensity (brightness) of the light emitting diodes 20 and 21, and specifically includes a current value. The illumination pattern information is information that defines a sin wave pattern, and includes, for example, a period and a phase shift amount (how much the phase is shifted by one phase shift). The illumination pattern may not be a sine wave, but may be a rectangular wave, for example.

  The creation of the illumination setting data may be enabled by input means such as a keyboard 6 and a mouse 7 for the illumination condition storage unit 10a.

  The illumination condition storage unit 10a may be provided in the pattern light illumination unit 2, may be provided in the imaging unit 3, or may be provided in any component of the image inspection apparatus 1.

  The control unit 41 once reads the illumination condition stored in the illumination condition storage unit 10a of the storage device 10, and outputs the illumination condition stored in the illumination condition storage unit 10a to the arithmetic device 2a of the pattern light illumination unit 2. Can be stored in the illumination condition storage unit 2b of the arithmetic device 2a. Thereby, when the pattern light illumination unit 2 receives an illumination trigger signal from the outside, the workpiece W can be illuminated according to the illumination condition stored in the illumination condition storage unit 2b, so that the illumination condition is stored in the illumination condition of the storage device 10. Compared with the case of reading from the unit 10a, the pattern light generation speed of the pattern light illumination unit 2 can be increased.

  As shown also in FIG. 36, the pattern light illumination unit 2 incorporates a current control unit 2c that controls the value of the current flowing through the light emitting diodes 20 and 21. The current control unit 2c is configured to be able to receive an illumination trigger signal. When receiving the illumination trigger signal, the current control unit 2c controls a current value that flows through the light emitting diodes 20 and 21 according to the illumination condition stored in the illumination condition storage unit 2b.

  A current control unit 2c that controls the first light emitting diode arrays A1 to A12 and a current control unit 2c that controls the second light emitting diode arrays B1 to B12 are provided, and all the current control units 2c have the same configuration. . The current control unit 2c shown in FIG. 36 controls the first light emitting diode array A1, and the current control unit 2c includes one D / A converter 2d, a plurality of sample and hold circuits 2e, and a plurality of voltage / And a current conversion circuit 2f. The sample-and-hold circuit 2e and the voltage / current conversion circuit 2f are provided in the same number as the number (12) of the light-emitting diodes 20 constituting the first light-emitting diode array A1. Twelve sample and hold circuits 2e are connected to the D / A converter 2d. A voltage / current conversion circuit 2f is connected to the output side of each sample and hold circuit 2e. Each light emitting diode 20 is connected to the output side of the voltage / current conversion circuit 2f.

  When switching patterns, the D / A converter 2d is configured to sequentially output control voltages for A1 to A12 as shown in FIG. The twelve sample and hold circuits 2e each sample the voltage of the waveform signal output from the D / A converter 2d at a predetermined sample timing based on the sampling signal input from the outside. After the first sample and hold circuit in FIG. 37 samples, the second sample and hold circuit samples and thus sequentially samples the voltages.

  The voltage value sampled by the first sample and hold circuit is converted into a current value corresponding to the voltage value by the voltage / current conversion circuit 2f, and the current of the current value flows to the light emitting diode A1. In this example, the voltage value sampled by the first sample and hold circuit is the lowest, and the voltage values sampled in the order of the second and third sample and hold circuits increase. That is, since the first current value is the lowest and the current value becomes higher in the order of the second and third current values, the brightness of the light emitting diodes A1 to A12 changes according to the current value. Pattern light having a periodic illuminance distribution is generated. By changing the waveform signal output from the D / A converter 2d, the illuminance distribution of the pattern light changes, and the illuminance distribution of the pattern light is expressed by a waveform that approximates the above-described sin waveform, or a triangular wave It can also be expressed by a waveform approximated to a square wave or a waveform approximated to a rectangular wave. Further, by setting the current value so that all the light emitting diodes 20 have the same brightness, it is possible to provide illumination with uniform illuminance on the entire surface.

  In this embodiment, the output voltage of the D / A converter 2d is used as the control voltage of each light emitting diode 20, and the sampling and holding circuit 2e for each light emitting diode 20 defines the timing, thereby sampling one D / A converter. The light quantity of the plurality of light emitting diodes 20 can be controlled by 2d. As a result, the number of high-speed, high-gradation D / A converters 2d having a large size can be reduced, and the pattern light can be generated by the small-sized sample hold circuit 2e. Therefore, the substrate area can be reduced and the cost can be reduced. Can be reduced.

  Since the light emitting diodes 21 of the second light emitting diode rows B1 to B12 are arranged in the Y direction, the X direction pattern light can be generated by controlling the current values of the second light emitting diode rows B1 to B12. In addition, since the light emitting diodes 20 in each of the first light emitting diode rows A1 to A12 are arranged in the X direction, the Y direction pattern light can be generated by controlling the current value of the first light emitting diode rows A1 to A12.

  Since the light emitting diodes 21 of the second light emitting diode rows B1 to B12 are arranged in the X direction, Y direction pattern light can be generated by controlling the current values of the second light emitting diode rows B1 to B12. In addition, since the light emitting diodes 20 in each of the first light emitting diode rows A1 to A12 are arranged in the Y direction, the X direction pattern light can be generated by controlling the current values of the first light emitting diode rows A1 to A12.

  Further, the wavelengths of the four Y-direction pattern lights shown in FIG. 5A may be different from the wavelengths of the four X-direction pattern lights shown in FIG. 5B. For example, the pattern light in the Y direction is emitted by irradiating red pattern light from the light emitting diodes 20 of the first light emitting diode arrays A1 to A12 and irradiating blue pattern light from the light emitting diodes 21 of the second light emitting diode arrays B1 to B12. And the wavelength of the X direction pattern light can be changed. In this case, if the workpiece W is simultaneously irradiated with the Y-direction pattern light and the X-direction pattern light, and captured by the imaging unit 3 including the color camera, the raw image by the irradiation of the Y-direction pattern light and the X-direction pattern light A raw image by irradiation can be obtained at the same time, and the time required for imaging can be shortened.

(Period of illumination distribution of pattern light)
When the illuminance distribution of the pattern light can be represented by a waveform that approximates the sin waveform, the period of the sin waveform can be set to 100 mm, for example. By setting the period to about 100 mm, even when imaging the surface of the work W with less regular reflection (not a perfect diffuse reflector), it is possible to perform a stacking process of a shape to be described later. The range can be widened. Moreover, attenuation by MTF of the lens of the condensing system optical system 32 of the imaging unit 3 is suppressed by setting the period of the sin waveform to about 100 mm. However, when inspecting a coating surface or the like, it may be preferable to shorten the cycle, and therefore the cycle is not limited to 100 mm. By shortening the period, it is possible to reduce the influence of the base when inspecting the coating surface, and it becomes easy to detect a subtle difference in the surface gradient.

(Generation of inspection images by deflectometry)
In this embodiment, the imaging unit 3 captures the workpiece W at a timing illuminated by the pattern light illumination unit 2 to obtain a plurality of luminance images, and the phase displacement is measured based on the plurality of luminance images captured by the imaging unit 3. The phase map calculated using the principle of phase measurement (PMD, hereinafter referred to as “deflectometry”) is processed to generate multiple inspection images that can detect different types of defects. The workpiece W can be inspected using the inspection image. The process of obtaining a plurality of luminance images can be executed by the control unit 41 outputting the illumination trigger signal and the imaging trigger signal to control the pattern light illumination unit 2 and the imaging unit 3 as described above. The process of generating the inspection image can be performed by the image generation unit 42 shown in FIG.

  The image generation unit 42 generates at least an inspection image indicating the reflection state of the surface of the workpiece W and an inspection image indicating the shape of the workpiece W based on the plurality of luminance images captured by the imaging unit 3. Examples of the inspection image indicating the reflection state of the surface of the workpiece W include a regular reflection component image and a diffuse reflection component image. Examples of the inspection image indicating the shape of the workpiece W include a shape image, a depth contour image, and a gloss ratio image.

  Hereinafter, the generation of the inspection image will be described in detail according to the flowchart shown in FIG. 21 and the schematic diagram shown in FIG. In step SA1 of the flowchart, the control unit 41 controls the pattern light illumination unit 2 and the imaging unit 3 to obtain a plurality of luminance images (raw images). The luminance image obtained in step SA1 is an intermediate image, and is an image that is temporarily stored in the storage device 10 or the like but is not displayed on the display unit 5. The luminance image is an image obtained by imaging the workpiece W illuminated in different illumination modes (illumination by a plurality of pattern lights).

  In step SA1, the control unit 41 outputs an illumination trigger signal to the pattern light illumination unit 2. When the pattern light illumination unit 2 receives the illumination trigger signal, the pattern light is generated according to the illumination condition stored in the illumination condition storage unit 2a, and the work W is illuminated. The illumination conditions at this time are as follows: Y direction pattern light at 0 °, Y direction pattern light at 90 °, Y direction pattern light at 180 °, and Y direction pattern light at 270 ° shown in FIG. 5A. FIG. 5B shows an illumination that sequentially generates an X direction pattern light at 0 °, an X direction pattern light at 90 °, an X direction pattern light at 180 °, and an X direction pattern light at 270 °. It is a condition. Accordingly, the pattern light illuminator 2 has a total of eight types of pattern light (four types in the X direction and four types in the Y direction) in which the phase of the illuminance distribution is shifted in both the arrangement direction of the light receiving elements 3a and the movement direction of the workpiece W. ) And sequentially irradiate the work W.

  At the same time, the control unit 41 outputs an imaging trigger signal to the imaging unit 3. When receiving the imaging trigger signal, the imaging unit 3 captures an image of the workpiece W every time the pattern light is irradiated. When the screen size is 8K (8192 columns × 1024 rows), 1024 times (number of rows) × number of times of pattern light illumination (8 times) is the number of times of illumination necessary to obtain one luminance image. This is the number of times of imaging.

  In this embodiment, a plurality of imaging trigger signals (specifically, the same number of imaging trigger signals as the number of rows of pixels of one luminance image) are sequentially transmitted to obtain one luminance image. Every time a trigger signal is received, the shift in imaging timing can be eliminated. Similarly, since the illumination trigger signal is transmitted to the pattern light illumination unit 2 and the illumination trigger signal and the imaging trigger signal are synchronized, the deviation of the illumination timing can be eliminated. Therefore, even when the number of times of illumination and the number of times of imaging are increased when generating a plurality of luminance images, the deviation between the imaging timing and the illumination timing can be maintained in an extremely small state.

  Since the number of times of pattern light irradiation is 8 at the time of imaging, 8 luminance images are obtained. As shown in FIG. 22, four luminance images (X) captured at the time of irradiation with four types of X direction pattern light and four luminance images (Y at the time of irradiation of four types of Y direction pattern light) ) Is obtained.

  FIG. 23 shows eight luminance images obtained by actually imaging the metal workpiece W. FIG. The images on the left side of FIG. 23 are, in order from the top, the X direction pattern light at 0 °, the X direction pattern light at 90 °, the X direction pattern light at 180 °, and the X direction pattern at 270 °. It is the brightness | luminance image obtained by each irradiating light. The images on the right side of FIG. 23 are, in order from the top, the Y direction pattern light at 0 °, the Y direction pattern light at 90 °, the Y direction pattern light at 180 °, and the Y direction pattern at 270 °. It is the brightness | luminance image obtained by each irradiating light. In addition, you may make it irradiate only X direction pattern light or only Y direction pattern light.

Thereafter, the process proceeds to step SA2 in the flowchart shown in FIG. 21, and the deflectometry process is performed on the eight luminance images obtained in step SA1. This can be performed by the image generation unit 42. By imaging the workpiece W irradiated with the pattern light, each pixel value of the obtained luminance image includes a regular reflection component and a diffuse reflection component (+ environment component). Since the phase of the illuminance distribution of the pattern light is shifted by 90 ° (π / 2) in the X direction and imaged four times, each pixel value can be obtained by irradiation with the X direction pattern light. The pixel values of the captured luminance image for the first time and I _1, the pixel values of the captured luminance image for the second time and I _2, the pixel values of the captured luminance image the third time and I _3, 4 time Assuming that the pixel value of the luminance image captured at I is I ₄ , the pixel values I _{1 to} I ₄ are given by the following equation 1.

  In Equation 1, Rd is a diffuse reflection component, Rs is a regular reflection component, and φs is a regular reflection angle (phase). The diffuse reflection component, the regular reflection component, and the regular reflection angle are phase data, and phase data for one line can be obtained based on a plurality of line images captured by the imaging unit 3.

Similarly, since the phase of the illuminance distribution of the pattern light is shifted 90 ° (π / 2) in the Y direction and imaged four times, each pixel value can be obtained by irradiation with the Y direction pattern light. Also in the Y direction, the pixel values I _{1 to} I ₄ can be expressed by Equation 1 above.

(Specular reflection component image)
The regular reflection component image is given by the following equation 2. In Equation 2, the diffusion component is excluded due to the difference between the opposite phases. As shown in FIG. 22, they are obtained in the X direction and the Y direction, respectively, and are combined to form a regular reflection component image. FIG. 29 shows an example of a regular reflection component image. Note that the normal image in FIG. 29 is an image including a regular reflection component and a diffuse reflection component.

(Regular reflection angle)
The regular reflection angle is given by the following equation 3. The angle is calculated as tan θ = sin θ / cos θ based on the regular reflection component shifted by π / 2.

(Average image)
The average image includes a diffusion component and an environmental component, and is given by the following expression 4. The regular reflection component is eliminated by adding the opposite phases.

(Diffuse reflection component image)
The diffuse reflection component image is given by the following equation 5. An example of the diffuse reflection component image is shown in FIG.

  In step SA3 in the flowchart of FIG. 21, contrast correction is performed on the diffuse reflection component image. In step SA4, contrast correction is performed on the regular reflection component image. Each contrast correction can be a linear correction. For example, correction is performed so that the average ROI becomes the median value. In the case of 8 bits, 128 levels may be used as the median value. As a result, a corrected diffusion component and a corrected regular reflection component are obtained.

  In step SA5, the phase component is compared with the reference phase. In step SA5, a difference is acquired with respect to the phase of the reference plane. For example, the user designates a spherical shape, a cylindrical shape, a planar shape, or the like as the reference plane, and obtains a difference from these. Or you may make it extract with a free-form surface. A corrected phase (difference) is obtained for the X direction, and a corrected phase is also obtained for the Y direction. This corresponds to the phase image shown in FIG. An example of the phase image after correction is shown in FIG.

  The diffuse reflection component image, the regular reflection component image, and the reference phase difference image are output images.

  In step SA6, a hierarchized image and a depth contour image are obtained based on the reference phase difference image obtained in step SA5. The hierarchized image is an image in which 1/2 reduction is repeated. Thereby, hierarchized phase images are obtained in the X and Y directions, respectively.

  On the other hand, the depth contour image is an intermediate image in which a portion having a large phase difference is emphasized, and is a concept different from curvature. The depth contour image is obtained at a higher speed than the shape image obtained by stacking the shapes, and has the advantage that the line flaw of the workpiece W is extremely easy to see and the contour can be easily extracted. An example of the depth contour image is shown in FIG.

  Next, in step SA7, shape images are generated by performing shape accumulation on the layered phase images. A shape image can be obtained by performing accumulation calculation by the Gauss-Jacobi method or the like on the regular reflection angles in the X direction and the Y direction. The shape image becomes an output image. An example of the shape image is shown in FIG.

  In general, there are many examples in which a shape is restored by triangulation after unwrapping, but in this embodiment, unwrapping is avoided and local differential values are accumulated and calculated by the Gauss-Jacobi method. Thus, the shape is restored regardless of the triangulation. A known method can be appropriately used as the shape restoration method. A method that does not use triangulation is preferable. In addition, a hierarchical method having a plurality of reduced images can be used. A method having a difference between a reduced image and a normal image can also be used.

  Further, a feature size can be set as a parameter. The feature size is a parameter for setting the size of the wound to be detected according to the purpose and type of inspection. For example, the finest flaw can be detected when the feature size parameter value is 1, and a large flaw can be detected by increasing this value. Accordingly, when the feature size is increased, a larger scratch is easily detected, and the unevenness on the surface of the workpiece W becomes clear.

  In step SA8, simple defect extraction is performed. Details of the simple defect extraction will be described later. In step SA8, a defect extraction image displaying the defects extracted after the simple defect extraction is output.

  The image generation unit 42 can also generate a gloss ratio image. The gloss ratio image is an image representing the ratio between the regular reflection component and the diffuse reflection component. In the gloss ratio image, pixels having different ratios of the regular reflection component and the diffuse reflection component are emphasized. An example of the gloss ratio image is shown in FIG.

(Configuration of the filter processing unit 40)
The filter processing unit 40 shown in FIG. 2 includes a filter processing setting unit 40a capable of individually setting filter processing application and filter processing non-application for each inspection image generated by the image generation unit 42, and filter processing setting. A filter processing execution unit 40b that executes the filter process on the inspection image set to be applied by the unit 40a. The type of filter to be applied is not particularly limited. For example, it can be selected according to the type of inspection image, and examples include a shading correction filter and a smoothing filter.

  As shown in FIG. 30, the shading correction filter is not suitable for a shape image, a gloss ratio image, a depth contour image, and a phase image. The reason for this is that the effect of the shading correction filter cannot be obtained because the shape image is not a brightness image but an image showing unevenness. In addition, since the gloss ratio image is an image for which the ratio has been obtained, the shading disappears in the first place. In addition, the depth contour image and the phase image are corrected in consideration of the phase, and there is no point in applying the shading correction filter. On the other hand, a shading correction filter is suitable for regular reflection component images, diffuse reflection component images, and normal images.

  The median filter in FIG. 30 is a smoothing filter and is not suitable for a shape image, but is suitable for a gloss ratio image, a depth contour image, a phase image, a regular reflection component image, a diffuse reflection component image, and a normal image. .

  The filter processing setting unit 40a is configured to obtain information on the type of inspection image and automatically set application of filter processing and non-application of filter processing in accordance with the inspection image. Information regarding the type of inspection image can be obtained from the image generation unit 42. As shown in FIG. 30, the filter processing setting unit 40a automatically applies the shading correction filter to the regular reflection component image, the diffuse reflection component image, and the normal image, thereby forming the shape image, the gloss ratio image, the depth contour image. And not automatically applied to phase images. The filter processing setting unit 40a does not automatically apply the median filter to the shape image, but automatically applies it to the gloss ratio image, the depth contour image, the phase image, the regular reflection component image, the diffuse reflection component image, and the normal image. Applicable.

  In other words, the effectiveness of the filter process is investigated in advance, and an inspection image to which the filter process is applied is preset in the image inspection apparatus 1, so that the filter processing setting unit 40a can respond to the type of the inspection image. Application and non-application of at least one of the shading correction filter and the smoothing filter can be automatically set. The preset content may be changed by the user.

  Since the filter processing execution unit 40b can execute the filter processing according to the preset content, the user selects the application and non-application of the filter processing for each inspection image, and the type of the filter processing in the case of application. It is not necessary to improve the operability. Further, since the filter processing setting unit 40a is configured to set the filter processing only on the inspection image used for the inspection, the filtering processing is not executed on the inspection image that is not used for the inspection. .

  The type of filter processing to be preset may be a filter whose effectiveness can be investigated in advance and a filter that shows the effect of the inspection image.

  An inspection image can be selected by a display image selection pull-down menu 58e of the defect extraction interface 58 shown in FIG. Selected as an inspection image by the display image selection pull-down menu 58e and selected as an inspection image (regular reflection component image, diffuse reflection component image, etc.) after the filter processing execution by the filter processing execution unit 40b and the inspection image In addition, the inspection image (shape image or the like) that has not been subjected to the filter processing by the filter processing execution unit 40b can be simultaneously displayed on the display unit 5. Even if the inspection image is suitable for the filter process, the filter processing execution unit 40b does not perform the filter process on the inspection image that has not been selected as the inspection image (the inspection image that is not displayed on the display unit 5). Can be. Even if the filtering process is not performed at this time, the filtering process execution unit 40b may perform the filtering process at a stage where the image is selected as the inspection image later.

  In addition, on the premise that filter processing application and filter processing non-application are automatically set according to the type of inspection image, the user automatically disables or sets the automatically set filter processing. The user may be able to change the type of the filtered processing. For example, the filter processing setting unit 40a can be configured to accept an operation in which the user does not apply the filter processing to an inspection image that is determined to require no filter processing. As a specific example of the operation, an interface can be displayed on the display unit 5, and various buttons and pull-down menus incorporated in the interface can be exemplified.

  The filter processing execution unit 40b performs the filter processing executed on the inspection image on the plurality of inspection images that have been subjected to the filter processing when the filter processing is executed on the plurality of inspection images. It may be configured to be non-executable in a batch. When the user performs an operation of not applying the filter process to the inspection image, the filter process can be automatically disabled for each inspection image. It is also possible to accept an operation for returning to the original state, that is, an operation for executing the filter processing on a plurality of inspection images, after the filter processing is collectively disabled.

  When performing each filter process, as shown in FIG. 31, various parameters such as the strength of the filter process can be set. The filter processing execution unit 40b is configured to be able to collectively set and change filter processing parameters for the inspection image set to be applied with the filter processing by the filter processing setting unit 40a. When a parameter is set or changed using the parameter setting interface shown in FIG. 31, the operation is reflected by the filter processing execution unit 40b on another inspection image set to apply the filter processing.

  In addition, the image for inspection to which the filter process is applied may not be preset in the image inspection apparatus 1. In this case, the user operates the various buttons and pull-down menus incorporated in the interface to set application / non-application of the filter processing individually or collectively for each inspection image. . Various buttons and pull-down menus incorporated in the interface serve as a filter processing setting unit.

  FIG. 32 is a diagram illustrating an inspection image before filter processing and an inspection image after filter processing. The filtering process is applied to the original image 1 (regular reflection component image) displayed in the first image display area 58a and the original image 2 (diffuse reflection component image) displayed in the second image display area 58b. ing. As shown in FIG. 32, the shading of the regular reflection component image and the diffuse reflection component image is corrected, and the defect portion is easily seen. On the other hand, since the filtering process is not applied to the original image 3 (shape image) displayed in the third image display area 58c, the defect portion related to the shape remains easily visible.

(Simple defect extraction)
As shown in the concept of simple defect extraction in FIG. 24, the simple defect extraction is an image 1 in which line flaws (defects) of the workpiece W are easily inspected, an image 2 in which dirt (defects) in the workpiece W is easily inspected, and This is a step of displaying the defects appearing in the images 1 to 3 on the defect extraction image after generating the images 3 that are easy to inspect dents (defects). The defect extraction image is an image that can extract and display the defects appearing in the images 1 to 3, and can be displayed by combining the extracted defects into one image, and is therefore referred to as a combined defect image. You can also.

  For example, the regular reflection component image is an image that makes it easy to check dirt that makes regular reflection dull, a scratch that does not change in shape but has a dull regular reflection, or a scratch that does not return regular reflection due to a shape change. The diffuse reflection image is an image in which it is easy to confirm the state of the texture on the surface of the workpiece W (specifically, characters on the printed matter, darkened stains, etc.). The shape image is an image obtained by accumulating changes in phase while viewing surrounding pixels according to the feature size. Here, when the feature size of the shape image is set to be large, it is possible to capture unevenness having a relatively shallow area and a large area even in the shape change. On the other hand, if the feature size of the shape image is set to be small, it is possible to catch a line scratch or a small scratch. In addition, defects that are difficult to appear in the shape image (for example, fine scratches or deep scratches) tend to appear in the regular reflection component image. In addition, the depth contour image calculates a reference plane, and images the deviation from the reference plane. From the depth contour image, it is possible to capture a line scratch or a small scratch. That is, the image generation unit 42 can generate a plurality of inspection images capable of detecting different types of defects based on the plurality of luminance images captured by the imaging unit 3. Further, the image generated by the image generation unit 42 is not limited to the image described above.

  The specular reflection component image, diffuse reflection image, shape image, depth contour image, gloss ratio image, defect extraction image, and the like generated by the image generation unit 42 are inspection images and can be displayed on the display unit 5. . Only one of the images generated by the image generation unit 42 may be displayed on the display unit 5 or a plurality of arbitrary images may be displayed. It is preferable that the image displayed on the display unit 5 can be selected by the user.

  For example, the UI generation unit 43 can generate the defect extraction interface 58 shown in FIG. 25, and the defect extraction interface 58 can be displayed on the display unit 5. In the defect extraction interface 58, a first image display area 58a for displaying the original image 1, a second image display area 58b for displaying the original image 2, a third image display area 58c for displaying the original image 3, A fourth image display area 58d for displaying the defect extraction image is incorporated. The number of image display areas is not limited to four, but may be three or less, or may be five or more. In FIG. 25, the regular reflection component image is selected as the original image 1, the diffuse reflection component image is selected as the original image 2, and the shape image is selected as the original image 3, but the image generated by the image generation unit 42 Any image may be displayed in any region.

  The user can also switch the images displayed in the first to third image display areas 58a to 58c to other images. When switching the displayed image, for example, the display region is selected and activated by operating the mouse 7 or the like, and the display image selection pull-down menu 58e incorporated in the defect extraction interface 58 is used to select the image. Selection can be made. The display image selection pull-down menu 58e is an image selection unit that selects at least one inspection image used for inspection from a plurality of inspection images generated by the image generation unit 42.

  In the display image selection pull-down menu 58e, a specular reflection component image, a diffuse reflection image, a shape image, a depth contour image, a gloss ratio image, and the like are displayed as options. Using the selected inspection image, the image generation unit 42 generates a defect extraction image. The display image selection pull-down menu 58e is an image selection reception unit that can receive selection of an inspection image for generating a defect extraction image from among a plurality of inspection images generated by the image generation unit 42. .

  The image inspection apparatus 1 is configured to be able to designate and enlarge a partial area of one inspection image among the inspection images displayed on the display unit 5. For example, when the user wants to enlarge the area B1 indicated by the broken line on the image displayed in the first image display area 58a of FIG. 25, the user places the pointer of the mouse 7 at the start point PA and continues to the end point PB. When a drag operation is performed with the mouse 7, a rectangular area whose diagonal is a straight line connecting the start point PA and the end point PB is designated, and this area becomes the area B1. This operation is an operation corresponding to an enlargement operation for enlarging by designating a partial region of one inspection image, and this enlargement operation is accepted by the operation accepting unit 46 of the control unit 4. The shape of the region designated by the enlargement operation may be, for example, a circle, a shape surrounded by a free curve, or the like. The enlargement operation may be performed by any operation of the mouse 7 and the keyboard 6.

  When the enlargement operation by the user is accepted, the display control unit 47 of the control unit 4 enlarges the area B1 of the image displayed in the first image display area 58a, and the first image display area as shown in FIG. 58a. Furthermore, the display control unit 47 displays the first image display area in the other inspection images (images displayed in the second to fourth image display areas 58b to 58d) displayed on the display unit 5 shown in FIG. Each area B2 corresponding to the area B1 designated in the image displayed at 58a is enlarged at the same magnification in conjunction with the enlargement operation and displayed on the display unit 5 (see FIG. 26). Although the expansion of the area B1 and the expansion of the area B2 can be performed at the same time, it may be accompanied by some time delay. The enlargement operation may be performed on any inspection image displayed in the first to fourth image display regions 58a to 58d, and any inspection image may be performed regardless of the inspection operation performed on any inspection image. Can be enlarged and displayed on the display unit 5 at the same magnification in conjunction with the enlargement operation.

  Further, the operation receiving unit 46 may be configured to be able to receive a reduction operation for reducing one of the inspection images displayed on the display unit 5. The reduction operation can be performed by, for example, a click operation of the mouse 7 or a key operation of the keyboard 6. The display control unit 47 may be configured to reduce other inspection images displayed on the display unit 5 at the same magnification in conjunction with the reduction operation and display them on the display unit 5.

  Further, the operation receiving unit 46 may be configured to be able to receive a scroll operation for scrolling one of the inspection images displayed on the display unit 5. The scroll operation can be performed by, for example, a click operation of the mouse 7 or a key operation of the keyboard 7. The display control unit 46 may be configured to scroll other inspection images displayed on the display unit 5 in conjunction with the scroll operation. The direction of scrolling can be any direction of the display unit 5 in the vertical direction, the horizontal direction, and the diagonal direction.

  A defect display interface 58 shown in FIG. 25 incorporates a detail display button 58f for selecting whether to perform detail display. When detailed display is performed by operating the detailed display button 58f, a threshold setting area 58i is displayed as shown in FIG. Each threshold value of the original images 1 to 3 can be displayed in the threshold value setting area 58i. The threshold value is a value for defining a pixel value range to be a non-defective part. For example, when the brightness level of each pixel is set to 256 levels from 0 to 255, the pixel value range to be a non-defective part can be defined by a specific numerical value from 0 to 255. Black may be a non-defect portion, and white may be a non-defect portion.

(Background selection method)
There are two threshold setting methods. The first is a method for selecting a background. The defect extraction interface 58 shown in FIG. 25 is provided with a background selection button 58g, and the background of each inspection image (original images 1 to 3) is selected after the background selection button 58g is pressed. Background selection can be performed on the original images 1 to 3 that have been enlarged and displayed after the enlargement operation. The background is a portion other than the defective portion of the workpiece W, that is, a non-defective portion of the workpiece W.

  As a method for selecting the background, for example, there are a method in which the pointer of the mouse 7 is placed on a non-defective part of the work W in the original images 1 to 3 and clicked, or a touch panel operation is performed. Thereby, the position (X coordinate, Y coordinate) of the non-defect portion of the workpiece W can be designated. The designation of the position of the non-defect portion can be performed a plurality of times for any one of the original images 1 to 3. In addition, after specifying the position of the non-defective portion with respect to any one image (first inspection image) among the original images 1 to 3, the position of the non-defective portion with respect to another image is also specified. You can specify. Note that when the background is selected, the pixel value range to be a non-defective portion is changed in a widening direction.

  This will be described based on the flowchart shown in FIG. When the user designates the position of the non-defective part of the workpiece W (first time) (step SB1), the first designation of the position of the non-defective part is performed by the control unit 4 as internal processing of the control unit 4. It is received by the position specification receiving unit 48. The position information (first non-defect portion position information) received by the position designation receiving unit 48 is stored in the position information storage unit 10b of the storage device 10 as a coordinate format.

  The setting unit 49 of the control unit 4 reads out the position information of the non-defective part received by the position designation receiving unit 48 from the position information storage unit 10b, and obtains the pixel value of the position of the non-defective part received by the position designation receiving unit 48. . Specifically, not only the pixel at the position of the non-defective part (clicked pixel) but also the pixel values (9 pixel values) of the 3 × 3 region around the pixel are obtained, and the maximum value and the minimum value are obtained. And ask. For example, if the maximum value is 200, the margin of 3 times the background selection sensitivity (for example, 5) is set as the margin, and 200 + 5 × 3 = 215 is set as the maximum value. For example, if the minimum value is 80, 80−5 × 3 = 65 is set as the minimum value. In this case, the pixel value range to be a non-defect portion is 215 to 65. The setting unit 49 includes a plurality of inspection images (including the first inspection image) displayed on the display unit 5 based on the pixel value at the position of the non-defective portion. ) Is automatically set (step SC1). The above sensitivity and margin are examples.

  Thereafter, when the user designates the position of the non-defective part of the workpiece W (second time) (step SB2), the second designation of the position of the non-defective part is performed as an internal process of the control unit 4. 4 is received by the position designation receiving unit 48. The position information of the non-defect portion (second non-defect portion position information) received by the position designation receiving unit 48 is similarly stored in the position information storage unit 10 b of the storage device 10.

  The setting unit 49 of the control unit 4 reads out the position information of the second non-defective portion received by the position designation receiving unit 48 from the position information storage unit 10b, and sets the second non-defective portion received by the position designation receiving unit 48. Get the pixel value of the position. Based on the pixel value at the position of the second non-defective part, the setting unit 49 sets a pixel value range that should be a non-defective part to a plurality of inspection images displayed on the display unit 5 (the first inspection-use image). (Including image) is automatically set (step SC2).

  When the user designates the position of the non-defect portion of the workpiece W (third time) (step SB3), the user should similarly make the non-defect portion based on the pixel value of the third non-defect portion position. The pixel value range is automatically set for a plurality of inspection images (including the first inspection image) displayed on the display unit 5 (step SC3). That is, the position designation receiving unit 48 can receive the designation of the position of the non-defective part a plurality of times.

  Further, an inspection image (second inspection image) that is not displayed on the display unit 5 and that has not been filtered is selected by a display image selection pull-down menu 58e of the defect extraction interface 58 shown in FIG. Then, the image displayed on the display unit 5 is switched (step SB4). When an inspection image that is not displayed on the display unit 5 and that has not been filtered is selected, the setting unit 49 has a plurality of positions indicating the positions of the non-defective portions stored in the position information storage unit 10b. Information (position information stored in steps SB1 to SB3) is read, and a pixel value corresponding to the position information in the inspection image is referred to. Thereafter, the pixel value range to be a non-defect portion is updated (step SC4). The filter processing unit 40 performs filter processing on the inspection image. Background selection can also be performed on the inspection image after switching (step SB5), and the position information (second non-defective portion position information) designated at this time is stored in the position information storage unit 10b.

  Furthermore, after an inspection image that is not displayed on the display unit 5 and that has not been filtered is selected as the second inspection image, another image is selected as the third inspection image. (Step SB6). When the third inspection image is selected, the setting unit 49 stores a plurality of pieces of position information (position information stored in steps SB1 to SB5) indicating the position of the non-defective part stored in the position information storage unit 10b. , And a pixel value range to be a non-defective part is updated with reference to pixel values corresponding to position information in the third inspection image. Although not shown, background selection can also be performed for the third inspection image, and the position information (third non-defect portion position information) designated at this time is stored in the position information storage unit 10b. The filter processing unit 40 performs filter processing on the third inspection image.

  That is, when the third inspection image is selected, the setting unit 49 has positional information (second non-defect) indicating the position of the non-defect portion in the second inspection image stored in the positional information storage unit 10b. Part position information) is read out, and a pixel value range to be a non-defective part can be updated by referring to a pixel value corresponding to the position information in the second inspection image. The setting unit 49 also includes position information (first non-defect portion position) indicating the position of the non-defect portion in the first inspection image stored in the position information storage unit 10b when the third inspection image is selected. Information) and position information indicating the position of the non-defect portion in the second inspection image (second non-defect portion position information) are read and correspond to the first and second non-defect portion position information in the third inspection image. The pixel value range to be a non-defective part may be updated with reference to the pixel value to be updated. The background selection history can be saved, for example, for 10 times, and thereafter the oldest can be deleted.

  The reason for selecting the background instead of the defective portion of the workpiece W is as follows. That is, if it is a method of clicking and specifying a defective part on the screen of the display part 5 one by one, a plurality of defect conditions must be set, and the operation becomes complicated. In addition to having to prepare a sample of each defective part, the user cannot deal with unknown defective parts, and the user feels stress in the designated work of small defective parts such as line scratches. Is also possible. Therefore, there are many cases where background selection is preferred, but there are cases where the method of specifying a defective portion described below is also effective, and in this embodiment, a method of selecting a background and a method of specifying a defective portion are used. Can choose.

(Forced extraction method)
The second method for setting the threshold is a method for specifying a defective portion (forced extraction method). For example, when the difference between the defective portion and the non-defective portion is not so large, it may be desired to set the threshold value by selecting the defective portion. In this case, the forced extraction method is effective.

  The defect extraction interface 58 shown in FIG. 25 is provided with a forced extraction button 58h, and after the forced extraction button 58h is pressed, a defective portion of each inspection image is selected (shown in FIG. 27). The forced extraction is to extract a defective portion of the workpiece W. The forced extraction can be performed on each inspection image displayed in an enlarged manner. The flow of forced extraction is almost the same as in the case of background selection shown in FIG.

  As a method of forcibly extracting, for example, there are a method of placing the pointer of the mouse 7 on a defective portion of the work W in the original images 1 to 3 and clicking and a method of operating a touch panel. Thereby, the position (X coordinate, Y coordinate) of the defective portion of the workpiece W can be designated. The designation of the position of the defective portion can be performed a plurality of times for any one of the original images 1 to 3. In addition, after specifying the position of the defective portion for any one of the original images 1 to 3 (first inspection image), the position of the defective portion is also specified for another image. It can be carried out. When forced extraction is performed, the pixel value range to be a non-defective portion is changed in a narrowing direction. Also, forced extraction and background selection can be performed on one original image.

  The designation of the position of the defective part of the workpiece W is received by the position designation receiving unit 48 of the control unit 4 shown in FIG. The position designation accepting unit 48 can accept designation of the position of the defective part a plurality of times. The position information (coordinates) of the defective portion received by the position designation receiving unit 48 is stored in the position information storage unit 10 b of the storage device 10.

  The setting unit 49 of the control unit 4 reads the position information of the defective portion received by the position designation receiving unit 48 from the position information storage unit 10b, and obtains the pixel value of the position of the defective portion received by the position designation receiving unit 48. In the case of forced extraction, unlike in the case of background selection, the pixel value of the pixel at the position of the defective portion (clicked pixel) is acquired, and the setting unit 49 determines that the non-defect is based on the pixel value of the position of the defective portion. A pixel value range to be a part is automatically set for a plurality of inspection images (including the first inspection image) displayed on the display unit 5. At this time, a pixel value range to be a non-defective part is set so as not to include a pixel value at the position of the defective part. However, when the pixel value range after the change is not an effective range, the upper limit value is set to 0 and the lower limit value is set to 255.

  Further, when an inspection image (second inspection image) that is not displayed on the display unit 5 and that has not been filtered is selected, the setting unit 49 stores the defect stored in the position information storage unit 10b. A plurality of pieces of position information indicating the position of the part are read out, and pixel values corresponding to the position information in the second inspection image are referred to. The pixel value range to be a non-defect portion in the second inspection image is updated. The filter processing unit 40 performs filter processing on the second inspection image. Forcible extraction can also be performed on the second inspection image, and the position information designated at this time is stored in the position information storage unit 10b.

  Furthermore, when another inspection image is selected as the third inspection image after the inspection image that is not displayed on the display unit 5 and is not filtered is selected as the second inspection image. In addition, the setting unit 49 reads a plurality of pieces of position information indicating the position of the defective part stored in the position information storage unit 10b, and refers to the pixel value corresponding to the position information in the third inspection image to determine the non-defective part. The pixel value range to be updated is updated. The filter processing unit 40 performs filter processing on the third inspection image.

  Further, when the third inspection image is selected, the setting unit 49 includes position information (second defect portion position) indicating the position of the defect portion in the second inspection image stored in the position information storage unit 10b. Information) is read out, and the pixel value range to be a non-defect portion can be updated by referring to the pixel value corresponding to the position information in the second inspection image.

  The setting unit 49 also indicates position information (first defect portion position information) indicating the position of the defect portion in the first inspection image stored in the position information storage unit 10b when the third inspection image is selected. And position information (second defect portion position information) indicating the position of the defective portion in the second inspection image, and refer to pixel values corresponding to the first and second defect portion position information in the third inspection image. Thus, the pixel value range to be a non-defect portion may be updated.

  The image generation unit 42 sets a region included in all pixel value ranges to be non-defective portions set for a plurality of inspection images by the setting unit 49 as a non-defective region, and is included in any pixel value range. A defect extraction image is generated in which a non-defective area is a defective area. This defect extraction image can be displayed in the fourth image display area 58d in FIGS. In addition, when background selection or forced extraction is performed, the pixel value range to be a non-defective part is changed. However, when the designation of the position of the non-defective part or the defective part is received by the position designation receiving unit 48, the image generating unit 42 can automatically update the non-defect area and the defect area in the defect extraction image.

  The display control unit 47 enlarges the region corresponding to the region designated by another inspection image in the defect extraction image displayed on the display unit 5 at the same magnification in conjunction with the enlargement operation, and displays it on the display unit 5. Can be displayed. Further, the display control unit 47 reduces the area corresponding to the area specified by another inspection image in the defect extraction image displayed on the display unit 5 at the same magnification in conjunction with the reduction operation. 5 can be displayed. Further, the display control unit 47 can scroll the defect extraction image displayed on the display unit 5 in conjunction with the scroll operation.

  Background selection can be performed after forced extraction, or forced extraction can be performed after background selection.

(Histogram and pin)
Further, as shown in FIG. 28, a histogram and a pin can be displayed at the time of setting a threshold value. For example, when an arbitrary position of the original image 1 displayed in the first image display area 58a is clicked with the mouse 7, a pin labeled “A” is displayed. Then, in the threshold setting area 58i, a pin with the same “A” is displayed at a position corresponding to the pixel value of the clicked point of the original image 1, and the pixel value of the clicked point of the original image 1 is displayed. I can know. When another point is clicked, a pin labeled “B” is displayed, and the pixel value at that position can be known. The pixel values of the A pin and the B pin can be distinguished and known. Three or more pins can be displayed. When a pin is displayed in the original image 1, the pin is similarly displayed at a corresponding position in another inspection image. When the inspection image is switched, a pin can be displayed at a corresponding position in the inspection image after switching.

  Note that the “pin” is an example of what the user designates an arbitrary position of the inspection image, and the display shape may not be a pin shape, for example, an arrow or a flag. May be.

  The threshold value setting area 58i can also display a histogram that is a frequency distribution of pixel values. The histogram can be generated by the histogram generation unit 42a of the control unit 4 shown in FIG. The histogram generation unit 42 a generates a histogram of a region including the position of the non-defect portion or the defect portion received by the position designation reception unit 48.

  In the threshold value setting area 58i, two threshold value display lines 58j each indicating an upper limit and a lower limit of a pixel value range to be a non-defective portion are displayed. The user sets the pixel value range to be a non-defective part and the defective part by dragging the threshold display line 58j with the mouse 7 while watching the histogram displayed in the threshold setting area 58i, for example. At least one of the power value range can be arbitrarily changed. This drag operation can be received by the operation receiving unit 46. That is, it is possible to accept a change in at least one of the pixel value range that should be a non-defective part and the pixel value range that should be a defective part on the histogram generated by the histogram generation part 42a. The setting unit 49 sets a pixel value range to be a non-defective part for a plurality of inspection images based on the changed pixel value range received by the operation receiving unit 46.

  The threshold setting method is not limited to the above-described method, and various methods can be used. For example, the threshold value can be set by the brightness ratio of the original image 1 and the original image 2 instead of a simple pixel value range. In addition, a threshold value can be set by combining a plurality of conditions. In this case, the user may be able to customize the logical operation (OR or NOT).

  In addition, the brightness of the processed image is determined using the distance used in statistics such as Mahalanobis distance, and a gray image is generated in a statistically rational manner according to the degree of deviation from the threshold. You can also.

  In addition, the background selection operation and the forced extraction operation can be performed by using the minimum value and the maximum value in the predetermined area, but even the pixel value in the predetermined area greatly deviates from other pixel values. The calculated pixel value may be removed for calculation. In addition, the standard deviation of the pixel values in the predetermined area can be used to enable robust operation even if there is a value such as an outlier. The predetermined area may be a rectangular area, or area segmentation may be used. This makes it possible to acquire a large number of pixels that are similar to some extent, so that it is easy to automatically set a threshold value.

  Further, the pixel value range of the non-defective portion may be automatically determined using clustering. This eliminates the need for multiple click operations. Alternatively, an appropriate threshold value may be set by designating a region including a defective portion and a region having no defective portion and finding outliers corresponding to the defect from them.

  Further, the threshold selection suitable for separating the defective portion from the non-defective portion can be determined by comparing the background selection and the forced extraction distribution. It is also possible to display whether or not the two groups are separable by comparing the background selection and the forced extraction distribution. It is also possible to compare the distribution of background selection and forced extraction, determine which image type is optimal for separating the two groups, and set a threshold value based on the image type.

  Furthermore, when performing background selection or forced extraction, the display of the inspection image may be binarized or displayed in gray scale. In the case of binarization, all the inspection image threshold values can be set as non-defective portions and other defective portions.

(Control of pattern light illumination unit by control unit 41)
In this embodiment, as shown in FIG. 23, the deflectometry process is performed after obtaining eight luminance images, but the algorithm of the deflectometry process is the irradiation of the pattern light emitted from the pattern light illumination unit 2. It is configured after specifying the order temporarily. In this embodiment, the irradiation order of the pattern light on the algorithm is Y direction pattern light in the case of 0 °, Y direction pattern light in the case of 90 °, Y direction pattern light in the case of 180 °, as shown in FIG. Y direction pattern light in the case of 270 °, X direction pattern light in the case of 0 °, X direction pattern light in the case of 90 °, X direction pattern light in the case of 180 ° shown in FIG. 5B, X in the case of 270 ° The algorithm is configured assuming that the direction pattern light is in order.

  Here, when the image inspection apparatus 1 is in operation, the moving workpiece W is imaged by the imaging unit 3, but the positional relationship between the pattern light illumination unit 2 and the imaging unit 3 is not in a predetermined state at the time of imaging. It is possible. In particular, in this embodiment, since the pattern light illumination unit 2 and the image pickup unit 3 are separate, the user can freely install the pattern light illumination unit 2 and the image pickup unit 3. It is assumed that the phase of the illuminance distribution is likely to be installed so that the phase shift direction is different from the direction specified by the algorithm.

  For example, the algorithm specifies the phase shift direction of the illuminance distribution of the pattern light as the X direction from the first irradiation to the fourth irradiation, but in the actual installation state, the fourth time from the first irradiation. If the phase is shifted in the Y direction until irradiation, it is possible to obtain a plurality of luminance images by repeating illumination and imaging, but inspection based on luminance images captured under inappropriate conditions A business image is generated. For this reason, the dents present on the workpiece W are less likely to appear in the inspection image, the dents that should be displayed in black are displayed in white, or the dents are displayed in a state where white and black are mixed. Sometimes.

  Specifically, as shown in FIG. 34, when the phase shift direction of the illuminance distribution of the pattern light is the direction specified by the algorithm, as shown on the left side of FIG. Is displayed on the inspection image so as to be black. However, as shown in the central part of the figure, when the orientations of the pattern light imaging unit 2 and the imaging unit 3 are 180 ° different from the direction assumed by the algorithm, a recessed defect portion is formed. It appears white. For this reason, there exists a possibility that a user may mistakenly recognize that it is a convex defect part. Also, as shown on the right side of the figure, when the positional relationship between the pattern light imaging unit 2 and the imaging unit 3 is actually reflected light reception but set to transmission light reception, a white portion And a black part are mixed and displayed.

  On the other hand, in this embodiment, the information acquisition unit 9 includes the moving direction information regarding the moving direction of the workpiece W with respect to the arrangement direction of the light receiving elements 3a of the line camera 31 of the imaging unit 3, and the light receiving elements 3a and the pattern light illumination unit. 2 is obtained, and the phase of the pattern light irradiated by the pattern light illumination unit 2 is obtained by the control unit 41 in accordance with the movement direction information and the positional relationship information acquired by the information acquisition unit 9. The shift direction can be determined.

  That is, even if the pattern light illumination unit 2 and the imaging unit 3 are installed such that the phase shift direction of the illuminance distribution is different from the direction specified by the algorithm, the movement direction information and the positional relationship information Based on the above, the phase shift direction of the pattern light irradiated by the pattern light illumination unit 2 can be reset to the direction specified by the algorithm.

  Therefore, it is not necessary to re-install the pattern light illumination unit 2 and the imaging unit 3. In addition, the pattern light illumination unit 2 and the imaging unit 3 can only be installed so that the phase shift direction of the illuminance distribution is different from the direction specified by the algorithm due to installation location restrictions and wiring relationships. However, it is possible to perform image inspection applying the principle of deflectometry.

  That is, when the pattern light illumination unit 2 and the imaging unit 3 are installed such that the phase shift direction of the illuminance distribution is different from the direction specified by the algorithm, an appropriate inspection image is obtained. Therefore, the irradiation order of the pattern light can be changed by controlling the first light emitting diode rows A1 to A12 and the second light emitting diode rows B1 to B12 so that an appropriate inspection image can be obtained.

(Generation of inspection image by image generation unit 42)
The image generation unit 42 can also generate an inspection image related to the shape of the workpiece W according to the movement direction information and the positional relationship information acquired by the information acquisition unit 9. Thereby, when the pattern light illumination unit 2 and the imaging unit 3 are installed such that the phase shift direction of the illuminance distribution is different from the direction specified by the algorithm, the pattern of the pattern light illumination unit 2 An appropriate inspection image can be obtained by the generation method of the image generation unit 42 without changing the light irradiation order.

  By obtaining the moving direction information and positional relationship information, it is possible to grasp how the pattern light is irradiated onto the workpiece W, and in what direction the phase shift direction of the pattern light is. Even if it exists, the image generation part 42 can handle the image and generate | occur | produce the image for a test | inspection which concerns on the shape of the workpiece | work W so that it may correspond with the shift direction of the phase of the pattern light specified by the algorithm. For example, in the algorithm, the phase shift direction of the illuminance distribution of the pattern light is specified as the X direction from the first irradiation to the fourth irradiation, and specified as the Y direction from the fifth irradiation to the eighth irradiation. However, in the actual installation state, the phase is shifted in the Y direction from the first irradiation to the fourth irradiation, and the phase is shifted in the X direction from the fifth irradiation to the eighth irradiation. In this case, the pattern light irradiation order is captured as it is, and after the imaging, a luminance image obtained by the fifth irradiation to the eighth irradiation is obtained by the fourth irradiation from the first irradiation on the algorithm. The luminance image obtained from the first irradiation to the fourth irradiation is handled as the luminance image obtained from the fifth irradiation to the eighth irradiation on the algorithm. In this way, by performing processing by replacing the actually captured luminance images, it is possible to perform image inspection that applies the principle of deflectometry without changing the installation state of the pattern light illumination unit 2 and the imaging unit 3. it can.

(Configuration of inspection department)
As shown in FIG. 2, the control unit 4 is provided with an inspection unit 4a. The inspection unit 4a performs a defect inspection of the workpiece W based on the inspection image generated by the image generation unit 42. For example, whether or not the workpiece W has a non-defective portion is determined based on the threshold value, and when it is determined that there is a non-defective portion, it can be notified.

(HDR function)
The image inspection apparatus 1 can incorporate a high dynamic range imaging (HDR) function. In the HDR function, the control unit 41 controls the pattern light illumination unit 2 and the imaging unit 3 so as to obtain a plurality of luminance images having different brightnesses. As a luminance image obtained by the HDR function, for example, there are a plurality of luminance images having different exposure times, a plurality of luminance images having different light emission intensities of the pattern light illumination unit 2, and a plurality of luminance images having different exposure times and light emission intensities. . For example, the image generation unit 42 can generate an inspection image having a dynamic range wider than the dynamic range of each luminance image by combining three luminance images having different brightnesses. Conventionally known methods can be used for the HDR synthesis method.

  In the HDR function, it is necessary to obtain a plurality of luminance images. In this case as well, as described in the trigger signal transmission section, when one encoder pulse signal from the outside is received, the illumination condition of the pattern light illumination unit 2 In addition, a plurality of imaging trigger signals are sequentially transmitted to the pattern light illumination unit 2 and the imaging unit 3 so that a plurality of luminance images are generated by changing at least one of the imaging conditions of the imaging unit 3. be able to.

(Multispectral lighting)
The pattern light illumination unit 2 may be configured to be capable of multispectral illumination. Multispectral illumination refers to irradiating the workpiece W with light having different wavelengths at different timings, and is suitable for inspecting color unevenness, dirt, and the like of a printed material (inspection object). For example, the pattern light illumination unit 2 can be configured so that yellow, blue, and red can be irradiated onto the workpiece W in order. Specifically, as the pattern light illumination unit 2 having a multi-color LED, Alternatively, the pattern light illumination unit 2 may be configured by a liquid crystal panel, an organic EL panel, or the like.

  The imaging unit 3 captures the workpiece W at the timing when light is irradiated to obtain a plurality of luminance images. The image generation unit 42 can obtain an inspection image by combining a plurality of luminance images. Here, the light can include ultraviolet rays and infrared rays.

(Effect of embodiment)
As described above, according to this embodiment, a plurality of pattern lights are sequentially irradiated onto the workpiece W, and each time the pattern light is irradiated, the workpiece W is imaged to generate a plurality of luminance images. Since phase data indicating the shape of the workpiece W is generated based on the image and an inspection image related to the shape of the workpiece W is generated, an image inspection applying the principle of deflectometry can be performed.

  Even if the pattern light illumination unit 2 and the imaging unit 3 are installed such that the phase shift direction of the illuminance distribution is different from the direction assumed by the algorithm, the workpiece with respect to the arrangement direction of the light receiving elements 3a. According to the movement direction information regarding the movement direction of W and the positional relationship information regarding the positional relationship between the light receiving element 3a and the pattern light illumination unit 2, the phase shift direction of the pattern light irradiated by the pattern light illumination unit 2 is set to an appropriate direction. Can be.

  Even if the pattern light illumination unit 2 and the imaging unit 3 are installed such that the phase shift direction of the illuminance distribution is different from the direction assumed by the algorithm, the movement direction information and the positional relationship information Accordingly, an image for inspection related to the shape of the workpiece W can be generated by the image generation unit 42.

  In addition, a plurality of inspection images can be displayed on the display unit 5 at the same time. In a state where a plurality of inspection images are displayed on the display unit 5 at the same time, when the user looks at a certain inspection image and designates the position of a non-defective part or a defective part of the workpiece W, the designated result is accepted, Based on the pixel value of the non-defect portion or the position of the defect portion, a pixel value range to be a non-defect portion can be set for a plurality of inspection images. Thereby, even if a user does not specify the position of a non-defect part or a defect part with respect to all the images for a test | inspection, the presence or absence of a defect can be determined with a some image for a test | inspection.

  In addition, a region included in all pixel value ranges to be set as non-defective portions set for a plurality of inspection images is defined as a non-defective region, and a region not included in any pixel value range is defined as a defective region. Since the defect extraction image can be generated, the user can detect different types of defects only by looking at the defect extraction image.

  In addition, when a user performs an operation of specifying and enlarging a partial area of one inspection image in a state where a plurality of inspection images are displayed on the display unit 5 at the same time, other inspection images are supported. The area to be displayed is enlarged at the same magnification and displayed on the display unit. Accordingly, a plurality of inspection images can be enlarged and displayed in the same manner with a simple operation. The user can see each inspection image in which the same area is enlarged and displayed at the same magnification, and can specify the position of the non-defective portion or the defective portion of the workpiece W in a certain inspection image.

In addition, when generating a plurality of inspection images that can detect different types of defects, the user views the inspection image that has been subjected to the filtering process and the inspection image that has not been subjected to the filtering process at the same time. be able to.
(Embodiment 2)
In the first embodiment, the function of generating the inspection image by performing the refractometry processing on the obtained luminance image has been described. However, the image inspection apparatus 1 according to the present invention has the deflectometry processing function. In addition, for example, a function of generating an inspection image using a photometric stereo method may be provided.

  Hereinafter, in the case of generating an inspection image using the photometric stereo method, the same portions as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted with reference to FIG. explain.

  The image inspection apparatus 1 according to the second embodiment can be configured similarly to the image inspection apparatus disclosed in, for example, Japanese Patent Application Laid-Open No. 2015-232486. That is, the image inspection apparatus 1 includes an imaging unit 3 that images the workpiece W from a certain direction, an illumination unit 200 that illuminates the workpiece W from three or more different illumination directions, and a control unit 400. The display unit 5, the keyboard 6, and the mouse 7 similar to those in the first embodiment are provided.

  The illumination unit 200 is configured to irradiate the workpiece W with light from different directions, and controls the first to fourth light emitting units 201 to 204 and the first to fourth light emitting units 201 to 204. And an illumination control unit 205. The illumination unit 200 is a part that performs multi-directional illumination that irradiates the workpiece W with light from different directions. The 1st-4th light emission parts 201-204 are arrange | positioned so that the workpiece | work W may be surrounded at intervals. The first to fourth light emitting units 201 to 204 can use light emitting diodes, incandescent bulbs, fluorescent lamps, and the like. Moreover, the 1st-4th light emission parts 201-204 may be a different body, and may be integrated.

  The control unit 400 includes a control unit 401, a normal vector calculation unit 402, a contour image generation unit 403, a texture rendered image generation unit 404, and a trigger signal transmission unit 405. The control unit 401 is configured to receive an encoder pulse signal when the encoder pulse signal is input from the outside. When the control unit 401 receives one encoder pulse signal from the outside, a trigger signal is transmitted so that a plurality of luminance images are generated by changing at least one of the illumination conditions of the illumination unit 200 and the imaging conditions of the imaging unit 3. The unit 405 is configured to sequentially transmit a plurality of imaging trigger signals to the imaging unit 3. In addition, when the control unit 401 receives one encoder pulse signal from the outside, the trigger signal transmission unit 405 is configured to sequentially transmit a plurality of illumination trigger signals to the illumination unit 200. In this embodiment, since the 1st-4th light emission parts 201-204 are lighted sequentially, an illumination trigger signal is transmitted 4 times. In synchronization with the transmission of the illumination trigger signal, the imaging trigger signal is transmitted four times.

  For example, when the illumination unit 200 receives the first illumination trigger signal, the illumination control unit 205 turns on only the first light emitting unit 201. At this time, the imaging unit 3 receives the imaging trigger signal and images the workpiece W at the timing when the light is irradiated. When the illumination unit 200 receives the second illumination trigger signal, the illumination control unit 205 turns on only the second light emitting unit 202, and at this time, the imaging unit 3 captures the workpiece W. In this way, four luminance images can be obtained. Note that the number of illuminations is not limited to four, and can be any number as long as the number of illuminations is three or more and the workpiece W can be illuminated from different directions.

  The normal vector calculation unit 402 calculates a normal vector with respect to the surface of the workpiece W of each pixel, using pixel values for each pixel that have a correspondence relationship between the plurality of luminance images captured by the imaging unit 3. The contour image generation unit 403 performs a differentiation process in the X direction and the Y direction on the calculated normal vector of each pixel, and generates a contour image indicating the contour of the inclination of the surface of the workpiece W. The texture rendered image generation unit 404 calculates the albedo of each pixel of the same number as the normal vector from the calculated normal vector of each pixel, and shows the pattern obtained by removing the tilt state of the surface of the workpiece W from the albedo. Generate a texture rendering image.

  Although not shown in the figure, also in the second embodiment, as in the first embodiment, for each inspection image displayed on the display unit 5, the non-defective part or defective part of the inspection object in the inspection image is displayed. A reception unit capable of receiving a designation of a position, and a non-defective part or a pixel value range to be determined as a non-defective part based on the pixel value of the position of the defective part received by the receiving part. A setting unit is provided. Furthermore, among the inspection images displayed on the display unit 5, an operation reception unit that can receive an enlargement operation for specifying and enlarging a partial region of one inspection image, and other display units displayed on the display unit 5. A display control unit is also provided that enlarges the region corresponding to the region specified in the one inspection image in the inspection image at the same magnification in conjunction with the enlargement operation and displays the region on the display unit. Of course, a reduction operation and a scroll operation can be performed instead of the enlargement operation. Furthermore, a filter processing unit (not shown) is the same as that in the first embodiment.

(Effect of embodiment)
According to the second embodiment, a plurality of inspection images capable of detecting different types of defects can be obtained using the photometric stereo method, and defect inspection is performed using the obtained inspection images. be able to.
(Embodiment 3)
FIG. 39 is a block diagram of the image inspection apparatus 1 according to the third embodiment of the present invention. The third embodiment is different from the first embodiment in that the image inspection apparatus 1 includes an edge generation unit 500, but the other parts are the same as those in the first embodiment. The same reference numerals are given to the parts and the description thereof is omitted, and different parts will be described in detail.

  When inspecting the workpiece W, for example, there is a case where it is desired to inspect a defect of a contour having a complicated shape, or a case where it is desired to inspect a defect within a specific region having a complicated shape. It is necessary to accurately extract the contour on the image for use. The edge generation unit 500 is a part for generating the outline of the workpiece W on the screen displayed on the display unit 5, and can be a part of the control unit 4.

  The outline of the workpiece W is also referred to as an edge. The edge is not only the outline of the workpiece W, but also the edge of the hole or recess formed in the workpiece W, the edge of the groove formed in the workpiece W, the workpiece W. In some cases, the outer shape of the bead provided, the outer shape of the seal member provided on the workpiece W, the edge of the sealant applied to the workpiece W, etc. In this embodiment, basically any edge is a screen. It can be generated and confirmed.

  The edge generation unit 500 receives on the inspection image displayed on the display unit 5 a position reception unit 501 that accepts designation of an arbitrary position that is an initial position for edge detection of the workpiece W, and an initial that is received by the position reception unit 501. An edge detection unit 502 that detects a position or an initial edge position in the vicinity of the initial position and specifies the gradient direction of the edge, and an edge tangent that is substantially perpendicular to the gradient direction of the edge detected by the edge detection unit 502 A search area setting unit 503 for setting a search area, which is an area for searching for an edge at a position that is a predetermined distance away from the detected edge in the edge tangential direction, and a search area set by the search area setting unit 503 A local threshold value setting unit for setting an edge position detection local threshold value effective in the search region based on the pixel value in And 04, and a edge connecting portion 505.

  The edge detection unit 502 detects an edge position in the search area based on a pixel value in the search area and a local threshold for edge position detection, and executes an edge detection process for specifying the gradient direction of the edge. The edge detection processing is repeatedly executed for the search areas sequentially set by the search area setting unit 503. The edge linking unit 505 is configured to specify the contour of the workpiece W by executing a linking process for linking edge positions sequentially detected in each search area.

  In this embodiment, the edge detection unit 502 detects the edge position and specifies the edge gradient direction. However, this is a process for assuming the edge tangent direction, and the edge gradient direction is determined. If the edge tangent direction is assumed without being specified, it is not necessary to specify the edge gradient direction.

  Hereinafter, a specific edge generation method by the edge generation unit 500 will be described based on a flowchart shown in FIG. In step SD1 of this flowchart, i = 1 is set. Thereafter, the process proceeds to step SD2, in which the user designates an arbitrary position as an initial position for detecting the edge of the workpiece W on the inspection image displayed on the display unit 5 by clicking the mouse 7. To do. The method for specifying the initial position is not limited to the operation of the mouse 7, and may be an operation of another input device.

  For example, on the inspection image shown in FIG. 41, a pointer (indicated by a white arrow) is placed on a line that the user recognizes as an edge, and the mouse 7 is clicked. Since it is considered that the user designates a part where the edge is easily understood on the inspection image, the initial position can be accurately specified by causing the user to indicate the initial position.

  The clicked position is received by the position receiving unit 501. Since the clicked position may slightly deviate from the edge, the edge detection unit 502, as shown in FIG. 42, coordinates having the strongest edge strength within the region S0 within the predetermined range including the clicked position, The coordinates of the portion where the pixel value difference is large are obtained, and the coordinates corresponding to the position are obtained as the initial coordinates P0 (step SD3). Thereby, even if the clicked position is slightly off the edge, the position can be corrected, and the initial coordinates can be placed on the edge. In step SD3, the gradient direction of the edge (the direction in which the pixel value changes) is also specified. As shown on the left side of FIG. 43, the gradient vector n that passes through the initial coordinates P0 and indicates the gradient direction of the edge is obtained. Ask. This is performed by the edge detection unit 502. If no edge exceeding the threshold is found, the process is terminated.

  In step SD4 following step SD3, a tangent vector r (tangent vector at the initial coordinate P0) substantially orthogonal to the gradient vector n is obtained, and this tangent vector r is set as a progress vector (unit vector). The direction of the progression vector can be assumed to be the edge tangent direction.

  Thereafter, the process proceeds to step SD5, and as shown on the right side of FIG. In step SD6, a segment S1 centered on the point Si is formed in parallel with the progress vector r. The segment S1 corresponds to a search area that is an area for searching for an edge. This is performed by the search area setting unit 503.

  After the segment S1 is formed, in step SD7, the pixels in the segment S1 shown on the left side of FIG. A pixel value is obtained, and this one-dimensional pixel value is obtained as edge information. The edge position is obtained from the obtained edge information. Since the binarization is performed in the segment S1, the binarization threshold value can be determined in a narrow area. The threshold value obtained in the segment S1 is the edge position detection local threshold value. The local threshold for edge position detection can be obtained by the Otsu method (discriminant analysis method). This is performed by the local threshold value setting unit 504. For example, the edge position may be determined by setting a local threshold for edge position detection with respect to the differential value of the one-dimensional pixel value.

  In step SD8, it is determined whether an edge position has been obtained. If NO in step SD8, the process returns to step SD5 via steps SD16 and SD17. If the edge position is not obtained even after a plurality of trials, the process is terminated.

  On the other hand, if YES is determined in step SD8 and the edge position is obtained, the process proceeds to step SD9, where the obtained edge position is set to Pi as shown on the right side of FIG. In step SD10, the progress vector is updated to a unit vector from Pi-1 to Pi.

  Thereafter, in step SD11, a segment is formed in parallel with the progress vector around the point Pi obtained in step SD9. In step SD12, the segment formed in step SD11 is binarized by degeneration, edge information is obtained, and an edge position is obtained from this edge information. In step SD13, the edge position obtained in step SD12 is set as Pi. In step SD14, the progress vector is updated to a unit vector from Pi-1 to Pi. In step SD15, i = i + 1. Thereafter, the process proceeds to step SD5.

  That is, by repeatedly executing the edge detection process for the search areas that are sequentially set, a plurality of edge positions (points P0 to P10 in this example) can be obtained as shown in FIG. 45A. After obtaining a plurality of edge positions, the edge connecting unit 505 connects the edge positions with lines in the order obtained (P0 → P1 → P2... P10 → P0). Can be specified. At this time, it may be determined whether or not the distance between P0 and P10 is equal to or smaller than a predetermined distance. If the distance is equal to or smaller than the predetermined distance, a method of connecting P0 and P10 may be adopted.

  When linked from P10 to P0, the process can be terminated with a closed region flag. P0 becomes the start point and end point of the contour. In some cases, the contour does not become a closed region. The contour of the workpiece W thus identified can be displayed in a state of being synthesized on the inspection screen in any color other than white and black.

  FIG. 45B shows a case where a contour has already been specified by a white point (edge position), and then P0 to P3 are obtained in order as edge positions. After obtaining P3, it is preferable to stop the process so as not to intersect with the already specified contour. In addition, after obtaining P3, the process may be terminated by connecting to P0 instead of a white point, thereby avoiding stray. Moreover, it is good also as a closed area | region comprised only by the edge position shown with the white point in FIG. 45B. The white dots on the drawing are only shown for convenience of explanation, and the color and form can be arbitrarily set. However, the edge position already obtained and the edge position obtained thereafter are It is preferable to display in different colors and forms.

  FIG. 45C shows a case where a contour has already been specified by a white point (edge position), and then P0 and P1 are obtained as edge positions. If there is an already specified contour in the segment S1 formed after obtaining P1, the process can be stopped. If P0 exists in the segment S1, it is only necessary to connect P0 without stopping the processing.

  FIG. 46 is a diagram illustrating a processing method when the curvature of the contour is small. As shown in FIG. 46, after obtaining the edge position P1, in order to obtain the next edge position, the segment S1 is formed at a predetermined distance L in the traveling vector direction. If the curvature of the contour is small, the contour is located outside the segment S1, and the edge position may not be detected.

  Thus, when the edge position cannot be detected in the segment S1, the search area setting unit 503 is configured to shorten the predetermined distance L and reset the segment S1. As shown in the second diagram from the top in FIG. 46, the predetermined distance L can be set to L / 2, for example. The edge detection unit 502 detects the edge position in the segment S1 reset by shortening the predetermined distance L and specifies the edge gradient direction. If the edge cannot be detected in the segment S1 even if the predetermined distance is L / 2, the predetermined distance is further shortened to form the segment S1.

  In the second diagram from the top in FIG. 46, when the pixels in the segment S1 are projected, the edges are projected obliquely with respect to the outline, so that the edges are blurred and the accurate edges may be difficult to understand. In contrast, as shown in the lower part of FIG. 46, the edge detection unit 502 sets the edge position detected in the segment S1 reset by the search area setting unit 503 as the temporary edge position P2, and sets the search area. The unit 503 sets a segment S1 ′ (reset search area) extending in a direction orthogonal to the vector t connecting the temporary edge position P2 and the edge position P1 detected immediately before the temporary edge position P2. Thereby, the edge becomes clear when the pixels in the segment S1 'are projected. The edge detection unit 502 is configured to detect an edge position in the segment S1 ', specify the gradient direction of the edge, and replace the detected edge position with the temporary edge position P2.

  47, for example, a bead, a sealing agent, an O-ring, or the like, the inspection object has a predetermined width C and has contours on both sides in the width direction. In the present embodiment, the contours on both sides in the width direction can be specified by applying the above-described method. Hereinafter, the method of specifying the contours on both sides will be described in detail based on the flowchart of FIG.

  In step SE1 of the flowchart of FIG. 48, i = 1 is set. Thereafter, the process proceeds to step SE2. In step SE <b> 2, the user designates an arbitrary position, which is an initial position for edge detection of the inspection object, on the inspection image displayed on the display unit 5 by a click operation of the mouse 7. For example, on the inspection image shown in FIG. 47 (partially shown), a pointer (indicated by a white arrow) is placed where the user recognizes that it is the center in the width direction of the inspection object. The mouse 7 is clicked. The clicked position is received by the position receiving unit 501.

  In step SE3, coordinates having a strong edge strength are obtained within a predetermined area S0 (shown in FIG. 49) including the clicked position, and the first edge position E0 is set. In step SE4, the gradient vector n is followed to find the corresponding edge position E0 '. The direction of the gradient vector n 'at the edge position E0' is opposite to the gradient vector n. An intermediate position between the edge position E0 and the edge position E0 'is set as an initial coordinate (control point) P0.

  In step SE5, the gradient vector n at the edge position E0 and the gradient vector n 'at the edge position E0' are averaged to calculate a progress vector r. In step SE6, as shown in FIG. 50, the coordinates (point Si) of the position separated by the progression vector r × L (predetermined distance) are obtained. In step SE7, a segment S1 centered on the point Si is formed in parallel with the progress vector r.

  In step SE8, one-dimensional pixel values are obtained as edge information by projecting (degenerate) the pixels in the segment S1 in a direction orthogonal to the edge gradient direction, and edge positions Ei and Ei 'are obtained from the edge information. In step SE9, it is determined whether an edge position has been obtained. If NO in step SE9, the process returns to step SE6 via steps SE17 and SE18. If the edge position is not obtained even after a plurality of trials, the process is terminated.

  On the other hand, if YES is determined in step SE9 and the edge positions Ei and Ei 'are obtained, the process proceeds to step SE10, and the intermediate position between the edge positions Ei and Ei' is set to Pi. In step SE11, the progress vector is updated to a unit vector from Pi-1 to Pi. Thereafter, in step SE12, a segment is formed in parallel with the progress vector around the point Pi obtained in step SE10. In step SE13, the segment formed in step SE12 is binarized by degeneration, edge information is obtained, and an edge position is obtained from this edge information. In step SE14, the edge position obtained in step SE13 is set as Pi. In step SE15, the progress vector is updated to a unit vector from Pi-1 to Pi. In step SE16, i = i + 1. Thereafter, the process proceeds to Step SE6. Accordingly, it is possible to obtain a plurality of edge positions on both sides by repeatedly executing the edge detection process on both sides in the width direction of the inspection object for the search areas set in sequence. After obtaining the edge position, the edge connecting unit 505 can specify the contours on both sides by connecting the edge positions with lines.

  An edge can be generated when the image inspection apparatus 1 is set, and the generated edge can be stored in the storage device 10 as a reference model line. After setting the image inspection apparatus 1, when the image inspection apparatus 1 is in operation, the inspection object is imaged to obtain an inspection image, the position of the inspection object in the inspection image is corrected, and the like. The edge of the inspection object is detected, and the detected edge and the reference model line are compared, and when the difference is equal to or larger than a predetermined value, it can be identified as a defective portion. This can be executed by the inspection unit 4a.

(Effect of embodiment)
According to the third embodiment, when the user designates the edge of the workpiece W or a position near the workpiece W on the inspection image displayed on the display unit 5, the search area is set and the threshold value is set in the search area. The edge position in the search area is repeatedly detected, and a plurality of edge positions can be obtained sequentially along the contour of the work W. The obtained edge positions are connected to automatically contour the work W. Can be identified. Therefore, the contour can be specified with high accuracy even with a simple operation, and the inspection accuracy can be improved.
(Embodiment 4)
FIG. 51 is a block diagram of the image inspection apparatus 1 according to the fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment in that the image inspection apparatus 1 includes the edge generation unit 300. However, the other parts are the same as those in the first embodiment, and hence the same as the first embodiment. The same reference numerals are given to the portions and the description thereof is omitted, and different portions will be described in detail.

  The edge generation unit 300 includes an edge detection region setting unit 301 for setting a plurality of edge detection regions at different positions on the inspection image displayed on the display unit 5, and a plurality of edge points in each edge detection region. By detecting and connecting adjacent edge points, a contour segment forming unit 302 that forms a contour segment constituting a part of the contour of the inspection object for each edge detection region and a contour segment forming unit 302 are formed. A connecting process for connecting the end of the other contour segment and the end of the other contour segment closest to the end, and repeating the connecting process until the open end of the contour segment disappears. And a closed region forming portion 303 to be formed.

  That is, the upper side of FIG. 52 shows the inspection image obtained by imaging the workpiece W, and the user can see the edge detection regions at different positions on the inspection image as shown in the center of FIG. 52 while viewing the inspection image. F1 and F2 are set. The edge detection areas F1 and F2 can be formed, for example, by surrounding a desired part in the workpiece W by an input operation of the mouse 7 or the keyboard 6 by the user, and the part surrounded by the operation is defined as an edge detection area setting unit. 301 sets the edge detection areas F1 and F2.

  In the edge detection area F1, edge points P1, P2, P3,... Are detected as shown in an enlarged view of a part of the center of FIG. The edge point can be detected by a conventionally known method, or can be detected by a method as in the third embodiment. By connecting adjacent edge points (for example, P1 and P2) to each other, a contour segment K1 constituting a part of the contour of the workpiece W is formed. A contour segment K2 is similarly formed in the edge detection region F2. This is performed by the contour segment forming unit 302.

  Note that the contour segment may be formed by the user specifying using an input device such as the mouse 7. In this case, the user designates at least the start point and the end point of the contour segment by operating the mouse 7 while viewing the inspection image displayed on the display unit 5. The contour segment forming unit 302 that has received the specification of the start point and the end point by the user sets a straight line connecting the start point and the end point as the contour segment. In this case, the user may additionally designate an intermediate point between the start point and the end point. Further, the contour segment is not limited to a straight line, and can be formed into a curved line by operating the mouse 7 or the like.

  As shown in the lower side of FIG. 52, the closed region forming unit 303 connects the end K1a of the contour segment K1 and the end K2a of the contour segment K2 closest to the end K1a by a connecting line L1 formed of a straight line. To do. Further, the end K1b of the contour segment K1 and the end K2b of the contour segment K2 closest to the end K1b are connected by a connecting line L2 made of a straight line. As a result, the open ends of the contour segments K1, K2 are eliminated, and the closed region M is formed. This closed area M becomes an inspection target area, and becomes an area where the inspection unit 4a performs defect inspection.

  The separation distance between the end K1a of the contour segment K1 and the end K2a of the contour segment K2 to be connected is set longer than the interval between adjacent edge points (for example, P1 and P2). . As a result, the end K1a of the contour segment K1 and the end K2a of the contour segment K2 are less likely to be mistakenly recognized as edge points.

  Further, in the case where it is desired to use the work W as shown in FIG. 53 as a region to be inspected, the edge detection regions F1 to F6 so as to surround the periphery of the work W as shown in the upper side of FIG. Form. Contour segments K1 to K6 are formed in the edge detection areas F1 to F6.

  After the formation of the contour segments K1 to K6, as shown on the lower side of the figure, the ends of the contour segments K1 to K6 are connected by connecting lines L1 to L6 to form a closed region M. In this example, the closed region M can be formed so as to remove the corner portion of the workpiece W, and therefore, for example, an inspection target region from which the chamfered portion and the R portion of the corner portion of the workpiece W are removed can be formed.

  When connecting the contour segments in both the case shown in FIG. 52 and the case shown in FIG. 53, the edge segments may be connected after all edge detection regions are formed, or the edge detection regions are formed. You may make it connect in order. Further, when connecting the contour segments, it is possible to prevent the connection processing from being performed on the already connected end portions. It is also possible to prevent the contour segments that are in a crossing relationship from being connected to each other. Furthermore, it is possible to perform a connection process that shortens the connection line. Furthermore, the end to be connected may be configured so that the user can manually select and change the end.

  It is also possible to prevent the connection process from being performed when the connecting line for connecting the contour segments exceeds a predetermined length. In this case, the contour segment does not constitute a closed region. When the length of the connecting line is equal to or longer than the predetermined length, it means that the two contour segments are greatly separated. In this case, the connecting process is not performed, and thus an incorrect connecting process is performed. Can be avoided. In addition, when the user can manually select the end portion to be connected, it is preferable that the connection is possible even if the length of the connecting line exceeds a predetermined length.

  Further, the connecting line is not limited to a straight line, and may be a curve such as a quadratic curve or a cubic curve, particularly a Pezier curve or a spline curve. Thereby, the edge part of a contour segment can be connected smoothly. Further, the connection line may be a combination of a curve and a straight line. Also, one contour segment and another contour segment can be connected by a curve having a tangent vector common to the tangent vector at the end of the one contour segment.

  FIG. 54 is a diagram for explaining a case where one workpiece W is imaged in two steps. The imaging unit 3 captures an upper portion of the workpiece W above the imaging boundary line R1 to obtain an upper partial inspection image (first partial inspection image), and is lower than the imaging boundary line R2 of the workpiece W. A part is imaged to obtain a lower partial inspection image (second partial inspection image). Accordingly, a predetermined range between the imaging boundary line R1 and the imaging boundary line R2 in the workpiece W is an overlapping portion included in the imaging ranges of both the upper partial inspection image and the lower partial inspection image. Note that the setting of the imaging range of the workpiece W is not limited to the above example, and may be an imaging mode that divides in the left-right direction or an imaging mode that divides into three or more.

  In this case, as shown on the left side of FIG. 54, the edge detection areas F1 to F6 are formed by the upper partial inspection image. At this time, in the upper partial inspection image, the workpiece W exists until it comes into contact with the imaging boundary line R1, but an operation of extending the lower end portions of the edge detection areas F1, F3, F4, and F6 to the limit of contact with the imaging boundary line R1. Is difficult to perform on the upper partial inspection image, when the user performs an operation to extend the lower ends of the edge detection areas F1, F3, F4, and F6, the user stops at a position just before touching the imaging boundary line R1. Can be considered.

  In contrast, in the present embodiment, the lower end portions of the edge detection regions F1, F3, F4, and F6 reach the overlapping portion of the upper partial inspection image with the lower partial inspection image, and the contour segment K1 , K3, K4, and K6 are located in the overlapping portion, the lower end of the contour segment K1 and the lower end of the contour segment K4 are connected by the connecting line L1, and the lower end of the contour segment K3 And the lower end of the contour segment K6 are connected by a connecting line L2. Thereby, the closed region M can be formed. As shown on the right side of FIG. 54, the same processing can be performed for the lower partial inspection image.

  That is, a plurality of contour segments (K1, K3, K4, K6) are overlapped with another partial inspection image (lower partial inspection image) in one partial inspection image (upper partial inspection image). When the end portion is located, even if there is no edge detection region at the end portion of the contour segment, the processing of connecting the end portions of the contour segment with a connecting line can be automatically performed.

  Thereafter, the portions other than the closed region M are blackened as non-inspection target regions, while the closed region M (shaded region) is whitened as the inspection target region. Similarly, in the lower partial inspection image, a non-inspection target area and an inspection target area can be set. Thereby, even if it is a case where the workpiece | work W is image | photographed separately, all the range which wants to test | inspect with simple operation can be made into inspection object.

(Effect of embodiment)
According to the fourth embodiment, when the user sets a plurality of edge detection areas, a plurality of edge points are detected in each edge detection area and the edge points are connected to form a plurality of contour segments. It is possible to connect the end portions of the contour segments to form a closed region, and to perform a defect inspection of the workpiece W using the closed region as an inspection target region.

(Other embodiments)
The present invention is not limited to the embodiments 1 to 4 described above. For example, as in the first modification shown in FIG. 55, the image generation apparatus 42 can be incorporated in the imaging section 3 as the configuration of the image inspection apparatus 1. As a result, the imaging unit 3 performs up to the creation of the inspection image by the deflectometry process, and the control unit 4 performs other processes. That is, a smart camera in which the image pickup unit 3 has an image processing function can be provided.

  Further, as in Modification 2 shown in FIG. 56, the pattern light illumination unit 2 and the imaging unit 3 can be integrated, and the control unit 4 can be separated. In this case, the imaging unit 3 can be built in the pattern light illumination unit 2, or the pattern light illumination unit 2 can be built in the imaging unit 3.

  Further, as in Modification 3 shown in FIG. 57, all of the imaging unit 3 and the control unit 4 may be integrated so that the control unit 4 is incorporated in the imaging unit 3.

  Moreover, all of the pattern light illumination part 2, the imaging part 3, and the control unit 4 can also be integrated.

  The above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  As described above, the image inspection apparatus according to the present invention can be used when a defect of an inspection object is inspected using images obtained by imaging various inspection objects.

DESCRIPTION OF SYMBOLS 1 Image inspection apparatus 2 Pattern light illumination part 3 Imaging part 3a Light receiving element 5 Display part 9 Information acquisition part 10 Storage apparatus 10b Position information storage part 31 Line camera 40 Filter process part 41 Control part 42 Image generation part 48 Position designation reception part 49 Setting section 58e Display image selection pull-down menu (image selection section)
W Inspection object (work)

Claims (5)

In an image inspection apparatus that inspects a defect of an inspection object using an image obtained by imaging the inspection object,
An illumination unit for irradiating the inspection object with light;
An imaging unit that captures an inspection object at a timing illuminated by the illumination unit to obtain a plurality of luminance images;
An image generation unit that generates a plurality of inspection images based on the plurality of luminance images captured by the imaging unit;
An image selection unit that selects at least one first inspection image used for inspection from the plurality of inspection images generated by the image generation unit;
A display unit capable of displaying the first inspection image selected by the image selection unit;
A receiving unit capable of receiving a plurality of designations of a position of a non-defective part or a defective part of an inspection object in the first inspection image for the first inspection image displayed on the display unit;
A position information storage unit that stores position information of a plurality of non-defective portions or defective portions received by the receiving unit;
Based on the pixel value of the non-defective part or the position of the defective part received by the receiving part, the pixel value range to be the non-defective part is automatically set for the first inspection image displayed on the display part. And a setting section for setting automatically,
The setting unit includes a non-defect portion or a defect portion stored in the position information storage unit when an inspection image not displayed on the display unit is selected as a second inspection image by the image selection unit. A plurality of pieces of position information indicating the positions of the second inspection image, and a pixel value range to be the non-defective part is updated with reference to a pixel value corresponding to the position information in the second inspection image. An image inspection apparatus. The image inspection apparatus according to claim 1,
The display unit is configured to be able to display a plurality of the inspection images,
The image generation unit sets a region included in all pixel value ranges to be non-defective portions set for the plurality of inspection images displayed on the display unit by the setting unit. An image inspection apparatus configured to generate a composite defect image in which a region not included in any pixel value range is a defective region. The image inspection apparatus according to claim 1 or 2,
A filter processing unit that performs a filter process on the inspection image;
After the second image for inspection is selected by the image selection unit, the setting unit is configured to use, as a third image for inspection, an image for inspection that is not displayed on the display unit and is not subjected to filter processing. When selected, a plurality of position information indicating the position of the non-defect portion or the defect portion stored in the position information storage unit is read, and a pixel value corresponding to the position information in the third inspection image is referred to. Configured to update the pixel value range to be the non-defect portion,
The image inspection apparatus, wherein the filter processing unit is configured to perform a filter process on the third inspection image. The image inspection apparatus according to claim 3.
The reception unit can receive the designation of the position of the non-defective part or the defective part of the inspection object in the second inspection image for the second inspection image displayed on the display unit a plurality of times. Configured,
The position information storage unit is configured to store position information of a non-defect portion or a defect portion in the second inspection image received by the reception unit,
The setting unit is a position indicating a position of a non-defect portion or a defect portion in the second inspection image stored in the position information storage unit when the third inspection image is selected by the image selection unit. An image inspection apparatus configured to read out information and update a pixel value range to be the non-defective portion with reference to a pixel value corresponding to the position information in the third inspection image . The image inspection apparatus according to claim 4,
The setting unit is a position indicating a position of a non-defect portion or a defect portion in the first inspection image stored in the position information storage unit when the third inspection image is selected by the image selection unit. Information and position information indicating the position of the non-defect portion or the defect portion in the second inspection image, and the non-defect portion by referring to the pixel value corresponding to the position information in the third inspection image An image inspection apparatus configured to update a pixel value range to be updated.