JP2009236760A - Image detection device and inspection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image detection device and an inspection apparatus for measuring the actual size (dimension) of an undefined area having damage, foreign substance, etc. <P>SOLUTION: The image detection device 6 detects the presence of the undefined area having damage or foreign substance from a work 2 by an optical image processing means. This image detection device 6 is provided with an image acquiring section 61 for acquiring work images of the work 2 photographed by external filming equipment, an image generating section 62 which uses a variable work image adjusted for the work image acquired by the image acquiring section 61 to generate a difference image from the work image and the variable work image, and a dimension calculating section 63 for calculating dimensions of the undefined area from the difference image generated by the image generating section 62. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image detection apparatus that measures the size of foreign matter on a workpiece to be inspected, and an inspection apparatus that inspects a workpiece to be inspected.

Conventionally, when visual inspection of a workpiece to be inspected is performed, the quality of the workpiece is determined visually. For this reason, the standard for visual quality judgment changes depending on the skill level of the worker, and the quality judgment of the workpiece varies.
In view of this, an inspection apparatus that uses a photograph of a workpiece and analyzes the photographed image to determine whether the workpiece is good or not is now being used due to advances in image processing technology (see, for example, Patent Document 1).

  The inspection apparatus described in Patent Document 1 is an apparatus that inspects whether or not there is a foreign object (such as dust or dirt) or a flaw on the work surface. Shoot the reflected light.

Specifically, according to the inspection apparatus described in Patent Document 1, light is reflected at a site where there are no scratches or foreign objects on the workpiece surface, and light is irregularly reflected at an uncertain site where there are scratches or foreign objects. Therefore, when a workpiece is photographed under constant illumination, the brightness of the workpiece surface is photographed differently between an indeterminate part with scratches or foreign objects and a part without scratches or foreign substances. The quality of the workpiece is judged according to the difference.
JP 2005-201880 A

  By the way, a conventional image detection apparatus that is information processing used in the inspection apparatus described in Patent Document 1 described above analyzes a workpiece image photographed by the inspection apparatus using a pixel as a determination target, and has a scratch, a foreign object, or the like. The uncertain part is discriminated in pixel units, and the quality of the work is determined by the number of pixels of the uncertain part.

  However, in the above-described conventional image detection apparatus, since the pixel itself is the detection target as an indeterminate part, the actual size (dimension) of the indeterminate part cannot be measured.

  Therefore, in order to solve the above-described problems, an object of the present invention is to provide an image detection apparatus and an inspection apparatus that measure the actual size (dimension) of an indeterminate part having a scratch or a foreign object.

  In order to achieve the above object, the image detection apparatus according to the present invention detects whether or not there is an uncertain part such as a scratch or a foreign object on the work to be inspected by image processing using light. In an image detection apparatus, an image acquisition unit that acquires a workpiece image of a workpiece photographed by an external imaging device, and a variable workpiece image that is image-variable with respect to the workpiece image acquired by the image acquisition unit. A creation unit that creates a difference image from a work image, and a dimension calculation unit that calculates a dimension of an uncertain part such as a scratch or a foreign object from the difference image created by the creation unit are provided. . Note that the variable work image referred to here is an image obtained by performing image processing based on an image condition for changing the work image by the creation unit from the work image acquired by the image acquisition unit, or the variable work image. This refers to an image obtained by varying the photographing conditions for photographing a workpiece with respect to the image, acquired by the image acquisition unit, and varied with respect to the workpiece image.

  According to the present invention, it is possible to measure the actual size (dimension) of an indeterminate part having a scratch or a foreign object.

  Specifically, since the image acquisition unit, the creation unit, and the dimension calculation unit are provided, it is possible to measure the actual size (dimension) of an indeterminate part having a scratch or a foreign object. Become. As a result, the quality of the workpiece can be determined based on the dimensions, and the accuracy of the workpiece quality determination can be improved.

  On the other hand, in a conventional image detection apparatus, an image of a workpiece photographed by an inspection apparatus is analyzed using pixels as determination targets, and indeterminate parts having scratches, foreign objects, etc. are discriminated in units of pixels, and the indefiniteness is determined. The quality of the work is determined based on how many pixels there are. For this reason, in the above-described conventional image detection apparatus, the pixel itself is the detection target as an indeterminate part, and thus the actual size (dimension) of the indeterminate part cannot be measured.

  The said structure WHEREIN: The extraction part which extracts only uncertain parts, such as a damage | wound and a foreign material, among the difference images produced by the said creation part may be provided.

  In this case, since the extraction unit is provided, it is possible to omit a normal part other than an uncertain part in the difference image, and an uncertain part can be a target of work quality determination. It becomes possible to increase the accuracy of dimension calculation of an indeterminate part by the dimension calculation unit. Specifically, an uncertain part can be extracted and the image can be enlarged by the extracting unit, and the accuracy of the dimension calculation of the uncertain part can be increased.

  The said structure WHEREIN: You may extract indefinite site | parts, such as a damage | wound of a maximum dimension, and a foreign material, in the said extraction part.

  In this case, since a part with an indefinite maximum dimension is extracted from the difference image, it is possible to easily perform a non-defective product determination with a reference for determining the quality of the work as a part with an uncertain maximum dimension.

  In the above configuration, the dimension of an uncertain part such as a scratch or a foreign object is at least one diameter of the length dimension (major axis) in the longitudinal direction and the length dimension (minor axis) in the lateral direction of the uncertain part. There may be.

  In this case, it becomes possible to accurately measure the dimension of the uncertain part, and at least one of the length dimension in the longitudinal direction and the length dimension in the short direction of the uncertain part is used to determine the quality of the workpiece. It becomes possible to make it a standard. In addition, it is possible to meet the variety of criteria for determining the quality of a workpiece due to the presence of uncertain parts.

  The said structure WHEREIN: The said dimension calculation part may calculate the length dimension (major axis) of the longitudinal direction of uncertain parts, such as a damage | wound and a foreign material.

  In this case, the length dimension in the longitudinal direction of the uncertain part can be used as a criterion for determining the quality of the work, and in order to determine the quality of the work from the actual size (dimension) of the uncertain part. It is possible to improve the accuracy of workpiece quality determination.

  In the above configuration, the dimension calculation unit calculates the length dimension (major axis) and the length dimension (minor axis) in the longitudinal direction of uncertain parts such as scratches and foreign matters, You may calculate the rectangular site | part comprised from a length dimension (major axis) and the length dimension (minor axis) of a transversal direction.

  In this case, it becomes possible to use a rectangular part composed of the length dimension in the longitudinal direction and the length dimension in the short direction of the uncertain part as a reference for the quality determination of the work, and the actual part of the uncertain part It is possible to improve the accuracy of the workpiece quality determination in order to determine the quality of the workpiece from the size (dimension). In addition, a rectangular part composed of the length dimension in the longitudinal direction and the length dimension in the short direction of the indeterminate part can be used as a criterion for determining the quality of the work. It is possible to meet the diversity of criteria for determining whether or not the product is acceptable.

  The said structure WHEREIN: A translucent material may be sufficient as a workpiece | work. Specifically, it is preferable to use a translucent material for the workpiece, for example, a piezoelectric material or a lens-based material is preferable.

  The said structure WHEREIN: The quality determination part which determines the quality of the said workpiece | work by comparing and examining the said dimension calculated by the said dimension calculation part with the preset reference dimension may be provided.

  In this case, it is suitable for mass production for determining the quality of the workpiece.

  In order to achieve the above object, an inspection apparatus according to the present invention is an inspection apparatus for inspecting a workpiece to be inspected, and an illuminating unit having an annular light source unit for illuminating the workpiece, and imaging for imaging the workpiece. The image detection apparatus according to the present invention described above is directly or indirectly connected, and a holding unit that holds a work is disposed between the illumination unit and the photographing unit so as to be fixed or movable. When the photographing unit is arranged at a position deviated from the irradiation direction of the light irradiated to the workpiece from the light source unit of the illumination unit, and the workpiece has an uncertain part such as a scratch or a foreign object, the light source unit The light irradiated onto the workpiece is photographed by the photographing unit with its optical path changed by the uncertain part.

  According to the present invention, since the above-described image detection apparatus according to the present invention is directly or indirectly connected, it is possible to measure the actual size (dimension) of an indeterminate part having a scratch or a foreign object. It becomes possible, and it has an operation effect by the above-mentioned image detection device concerning the present invention.

  In addition, according to the present invention, it is possible to determine whether or not a workpiece is good without erroneous recognition even when the workpiece is held by a holding mechanism such as a holding unit. In particular, according to the present invention, the image detection device is connected directly or indirectly, and the photographing unit and the illumination unit are arranged via a work held by the holding unit. The photographing unit and the illumination unit are not provided in the same direction (position on the same side) with respect to the workpiece on the basis of the held workpiece. Therefore, the reflected light of the light irradiated on the work and the reflected light reflected by the holding part that holds the work are not photographed by the photographing part, and all foreign matters (dust and It is possible to find indeterminate sites including spots) and wounds. Further, according to the present invention, since the photographing unit and the illumination unit are not provided in the same direction (position on the same side) with respect to the workpiece on the basis of the workpiece held by the holding unit, the illumination unit It is possible to prevent the holding part from shining white by the illumination from the light, and it is possible to prevent erroneous recognition of the holding part due to white light emission and an uncertain part including foreign matter.

  According to the image detection apparatus and the inspection apparatus according to the present invention, it is possible to measure the actual size (dimension) of an indeterminate part having a scratch or a foreign object.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, a case where the present invention is applied to a filter that is an optical component as a workpiece to be inspected is shown.

  The inspection apparatus 1 according to the present embodiment adopts a transmission method, and inspects whether or not there is a foreign object on the workpiece to be inspected.

  Specifically, as shown in FIG. 1, the inspection apparatus 1 includes an illumination unit 3 that illuminates the workpiece 2, an imaging unit 4 that photographs the workpiece 2, and a holding unit 5 that holds the workpiece 2. An image detection device 6, which is an information processing device, is connected to the photographing unit 4 by wire.

  As shown in FIGS. 1 and 2, the illuminating unit 3 is formed of a cylindrical body having a through hole 31, and the upper part of the inner wall surface 32 of the through hole 31 in the plan view has a gradient toward the lower part of the plan view. It is formed into a tapered shape. In the upper part of the tapered inner wall surface 32 in plan view, a light source part 33 having a ring shape in plan view is provided, and the light source part 33 is configured by arranging a plurality of LEDs in a plurality of rows in two upper and lower stages. Further, each of the plurality of LEDs irradiates light in a direction perpendicular to the taper-formed inclination angle (irradiation in the direction of the one-dot chain line in FIG. 1). That is, the light source unit 33 irradiates the workpiece 2 held by the holding unit 5 with light having a directivity (in the direction of the one-dot chain line in FIG. 1) having an angle.

  In addition, the illumination unit 3 diffuses the light irradiation so as to face the front surface of the inner wall surface 32 formed in a tapered shape in front of the light irradiation direction from the light source unit 33. A diffusion filter 34 is provided (attached). The diffusion filter 34 is formed of a disc-like body having an outer periphery in plan view and an inner periphery in plan view. Thus, by attaching the diffusion filter 34, when there is an uncertain part including a scratch or a foreign substance on the work 2, glare due to light irradiation to the uncertain part can be suppressed, and as a result. The outline (contour) of the uncertain part can be clarified.

  The photographing unit 4 is provided with a camera that performs monochrome photographing, and this camera uses a seamless zoom lens. The photographing unit 4 is intended for photographing light having a wavelength shorter than that of red, and particularly desirably photographing single-wavelength light. In this embodiment, blue single-wavelength light is taken as an object to be photographed.

  The holding unit 5 is fixed to the inspection apparatus 1 and is disposed between the illumination unit 3 and the imaging unit 4. The holding unit 5 is configured to fix and hold the workpiece 2 by pressing the side surface of the workpiece 2.

  The image detection device 6 uses an image acquisition unit 61 that acquires a workpiece image of the workpiece 2 captured by the imaging unit 4 and a variable workpiece image that is image-variable with respect to the workpiece image acquired by the image acquisition unit 61. A creation unit 62 that creates a difference image from the workpiece image and the variable workpiece image by comparing the workpiece image with the variable workpiece image, and a size of an uncertain part such as a scratch or a foreign object from the difference image created by the creation unit 62 A size calculation unit 63 that calculates the size, an extraction unit 64 that extracts an uncertain part such as a scratch or a foreign object from the difference image created by the creation unit 62, and a reference in which the dimensions calculated by the size calculation unit 63 are set in advance. A pass / fail judgment unit 65 for judging pass / fail of the work 2 by comparing with the dimensions and a display unit 66 for displaying an image such as a work image are provided. Among these, the creation unit 62, the dimension calculation unit 63, the extraction unit 64, and the quality determination unit 65 are provided as components of an image processing unit (not shown) that performs image processing of the image detection device 6.

  Note that the extraction unit 64 here extracts a plurality of uncertain parts on the image and extracts only uncertain parts such as scratches and foreign objects having the maximum dimensions (see below).

  The variable work image referred to here is an image obtained by performing image processing based on an image condition for changing the work image by the creation unit 62 from the work image acquired by the image acquisition unit 61. As an image condition for changing the work image, for example, “blurring” by changing the focus of the work image can be cited.

  According to this image detection device 6, not only the work image (work image referred to in the present invention) photographed by the photographing unit 4 is arithmetically processed to inspect whether or not the work 2 has a foreign object, but also the work 2. If there is something (indeterminate part) in the image, measure whether this indeterminate part is larger than a preset dimension, and if the result of this measurement is more than a preset dimension, The uncertain part is determined as a foreign object, and the workpiece 2 on which the determined foreign object is attached or formed is determined as a defective product. In the present embodiment, when the standard dimension for discriminating a foreign object is 20 μm or more in the major axis and the major dimension is measured to be 20 μm or more, the indeterminate part is discriminated as a foreign substance.

  In the inspection apparatus 1 described above, the work 2 held by the holding unit 5 is disposed between the illumination unit 3 and the imaging unit 4. Further, the photographing unit 4 is arranged at a position deviating from the irradiation direction of the light irradiated to the work 2 from the light source unit 33 of the illumination unit 3.

  Further, the inspection apparatus 1 is arranged at an inclination with respect to the holding unit 5 holding the workpiece 2 below the illumination unit 3 in plan view (specifically, inclined about 45 degrees in this embodiment). A prevention plate 7 is provided. That is, the prevention plate 7 is provided at a position on the opposite side to the side where the photographing unit 4 of the illumination unit 3 is disposed. The prevention plate 7 is made of a glossy blackboard and faces the photographing unit 4 through the through hole 31 of the illumination unit 3. According to the prevention plate 7, the light reflected by the work 2 and the holding unit 5 that holds the work 2 (the two-dot chain line direction in FIG. 1) is guided (reflected) in a direction other than the photographing unit 4.

  In the inspection apparatus 1 having the above-described configuration, when the work 2 held by the holding unit 5 has an uncertain part including scratches or foreign matters, the light irradiated (illuminated) from the light source unit 33 to the work 2 is damaged. The optical path is changed by an uncertain part including a foreign object or a foreign object, and the image is captured by the imaging unit 4. The other light is not reflected on the camera of the imaging unit 4 without irradiating the imaging unit 4. The change of the optical path here means that the light is refracted or reflected by an uncertain part including a scratch or a foreign object.

  In the inspection apparatus 1 described above, the shortest distance from the photographing unit 4 (the lens end surface of the camera) to the work is set to 90 mm, and the shortest distance from the work 2 to the light source unit 33 of the illumination unit 3 is set to 30 mm. Yes. This setting is a setting in which the camera of the photographing unit 4 does not exist in the illumination direction (emission direction) of the light from the light source unit 33 of the illumination unit 3 through the work 2 having no uncertain part including a scratch or a foreign object. Yes, this numerical value is limited to the present embodiment, and is not limited to this setting. In other words, when the work 2 having no uncertain part including scratches and foreign matters is illuminated with light from the light source unit 33 of the illumination unit 3, the setting may be made so that the light of the camera of the photographing unit 4 does not enter.

  Next, FIG. 1 shows a method for detecting whether or not there is an uncertain part such as a scratch or a foreign object on the work 2 to be inspected in the image detection device 6 described above by image processing using light. A schematic block diagram of the image detection apparatus 6 shown in FIG. 3 and a flowchart shown in FIG.

  First, preparation for capturing an image of the workpiece 2 (hereinafter referred to as a workpiece image) is made (initial setting in step S1).

  Specifically, a work image to be displayed at the time of setting an inspection area, which will be described later, and a work image capture position are set (work image capture initial setting).

  When the work image capture initial setting is completed, initial setting of the shooting conditions (parameters) of the shooting unit 4 (camera) is performed (camera initial setting). Specifically, the shutter speed and camera sensitivity are set. This camera initial setting includes lens focus adjustment, aperture adjustment, zoom ratio adjustment, illumination brightness adjustment, and the like.

  When the work image capturing initial setting and the camera initial setting are completed, the shooting condition of the work 2 is set (imaging condition setting). Specifically, the shooting condition setting includes settings related to the actual size such as the actual distance from the shooting target to the shooting unit 4, the tilt angle, and the size corresponding to one pixel.

  After setting the imaging conditions, the imaging unit 4 captures the workpiece 2 and displays the captured workpiece image on the display unit 66 (see FIG. 4). Of the work images displayed on the display unit 66, an inspection area to be inspected is set (inspection area setting in step S2). Specifically, regarding the setting of the inspection area, first, the upper left point of the detection area is set on the image displayed on the display unit 66, and then the lower right point is set, and the upper left point and the lower right point are set as diagonal points. A rectangular detection area is set (see FIG. 5). In the image detection device 6, a setting for moving the detection area to be set to an arbitrary point or rotating in an arbitrary direction is added.

  After setting the detection area, a work image photographed by the photographing unit 4 and displayed on the display unit 66 is acquired (FIG. 4, step S3), and among the acquired work images, the detection area set in step S3 is trimmed. Then, the trimmed image of the trimmed detection area is displayed (FIG. 6, step S4).

  In step S4, a variable work image obtained by changing the image based on the image condition for changing the trimmed image (work image) is acquired from the trimmed image trimmed from the work image (step S5). Here, the variable work image refers to an image obtained by performing image processing based on an image condition for changing the work image by the creation unit 62 from the work image acquired by the image acquisition unit 61. Specifically, the creation unit 62 of the image detection device 6 performs image processing to blur the trimmed image and create a variable work image (FIG. 7). That is, changing the work image in this embodiment means blurring the work image.

  The work image of the detection area trimmed in step S4 (trimmed image shown in FIG. 6) and the variable work image created in step S5 (FIG. 7) are compared by the creating unit 62 to create a difference image (FIG. 8). Step S6).

  The difference image created in step S6 is binarized with subpixels (step S7), and the binarized work image is labeled to display a blob (FIG. 9, step S8). The blob here refers to a part surrounded by a white outer periphery shown in FIG. 9 and a part to be extracted by the extraction unit 64 (an uncertain part such as a wound or a foreign object).

  For the blob displayed in step S8, it is determined whether or not there is a blob having a predetermined area or more, and a blob having a certain area or more is selected and extracted by the extraction unit 64 (FIG. 10, step S9). In step S9, the extraction unit 64 extracts a plurality of uncertain parts on the work image.

  One arbitrary blob is selected from the blob extracted in step S9 (see the case where the blob is surrounded by the red outer periphery in FIGS. 11 and 12, step S10). FIG. 12 is an enlarged view of the blob selected in FIG.

  The maximum brightness in all pixels in the blob selected in step S10 is detected (step S11), and it is determined whether or not the detected maximum brightness is equal to or higher than a preset brightness (step S12).

  If the maximum luminance detected in step S12 is equal to or higher than the preset luminance (Yes in step S12), the imaging unit 4 changes the imaging condition (luminance in the present embodiment) again to capture the work image. Specifically, the shutter speed of the photographing unit 4 is set short in order to reduce the brightness (step S13), and the work image including the blob (specifically, the work image in the same detection area as the trimmed image described above) is captured again. (Step S14).

  Then, the maximum luminance in all the pixels in the blob captured in step S14 is detected, and it is checked whether or not the detected maximum luminance is less than a preset luminance (step S15).

  If the maximum luminance detected in step S15 is not less than the preset luminance (No in step S15, see arrow direction of symbol C), the shutter speed of the photographing unit 4 is set to be shorter to reduce the luminance (step S13). Then, the work image including the blob (specifically, the work image in the same detection area as the trimmed image described above) is captured again (step S14).

  Then, the maximum luminance in all the pixels in the blob captured in step S14 is detected again, and it is checked whether or not the detected maximum luminance is less than a preset luminance (step S15).

  In step S14 of the present embodiment described above, a work image in the same detection area as that of the trimmed image is captured. However, the present invention is not limited to this, and the work image is captured. Trimming may be performed.

  When the maximum brightness detected in step S15 is less than the preset brightness (Yes in step S15), the image is changed based on the image condition for changing the trimming image (work image) with respect to the trimming image including the blob. The variable work image is acquired (step S16). The variable work image referred to here is image processing based on an image condition in which the creation unit 62 changes the work image from the work image acquired by the image acquisition unit 61. Refers to the image. Specifically, the creation unit 62 of the image detection device 6 performs image processing to blur the trimmed image (work image) and create a variable work image. That is, changing the work image in this embodiment means blurring the work image.

  The creation unit 62 compares the workpiece image (trimming image) acquired in step S14 with the variable workpiece image created in step S16 to create a difference image (step S17).

  The difference image created in step S17 is binarized with subpixels (step S18), and the binarized work image is labeled to display a blob (FIGS. 13, 14, and step S19). FIG. 14 is an enlarged view of the blob in FIG.

  The size of the blob having the maximum area is calculated for the blob displayed on the work image in step S19 (step S20).

  If the maximum brightness detected in step S12 is less than the preset brightness (No in step S12, see arrow direction of symbol D), the size of the blob is calculated (step S20). In this case, the work image (trimmed image) acquired in step S3 and trimmed in step S4 is used.

  Specifically, the smallest rectangular part (specifically a rectangle) surrounding the blob is calculated, and the dimension of the rectangular part (rectangle) is calculated by the dimension calculation unit 63. Then, the length of the rectangle in the longitudinal direction (long side) is taken as the major axis, and the length in the short direction (short side) is taken as the minor axis (step S21). In the present embodiment, the major axis of the blob having the maximum area is calculated as 39.78 μm and the minor axis is calculated as 18.16 μm by the dimension calculating unit 63.

  And in order to calculate a rectangle also about another blob, step S10-step S21 are repeated (in step S22, refer to the arrow direction of a symbol B), and if processing is completed about all the blobs (Yes in step S22), all The blob with the longest diameter (the blob having the largest area) is selected from all the blob and displayed in a color different from the other blob (yellow in this embodiment) (step S23). .

  Then, the minimum rectangle surrounding the blob displayed in step S23 is displayed (step S24), and the midpoint of each side of the rectangle is displayed in a different color (blue in this embodiment) (step S25). In step S23 to step S25, the extraction unit 64 extracts only uncertain parts such as scratches and foreign matters having the maximum dimensions.

  The rectangle (rectangle) displayed in blue in step S25 is compared with the reference dimension set in advance by the quality determination unit 65, and the quality of the workpiece 2 is determined. Specifically, the pass / fail determination unit 65 determines whether the major axis of the rectangle displayed in blue in step S25 is less than 20 μm (step S26).

  If the major axis of the rectangle is less than 20 μm (Yes in Step S26), the work 2 including the blob is OK and the OK display (the major axis and the minor axis are also displayed) is performed on the display unit 66 (Step S27).

  When the major axis of the rectangle is 20 μm or more (No in step S26), the work 2 including the blob is judged to be defective and NG display (the major axis and the minor axis are also displayed) on the display unit 66 (step S28). .

  In step S26 to step S28, after determining whether the workpiece 2 is non-defective or defective based on the presence or absence of an uncertain part, if there is a workpiece 2 to be inspected next, return to step S3 again (No in step S29, sign A) (Refer to the direction of the arrow) The next work 2 is identified as a non-defective product or a defective product. Further, when the inspection of the workpiece 2 is to be ended (Yes in step S29), the inspection process is ended with the inspection of the workpiece 2 as it is.

  As described above, according to the image detection apparatus 6 according to the present embodiment, it is possible to measure the actual size (dimension) of an indeterminate part having a scratch or a foreign object. Specifically, since the image acquisition unit 61, the creation unit 62, and the size calculation unit 63 are provided, it is possible to measure the actual size (dimension) of an indeterminate part having a scratch or a foreign object. As a result, the quality of the workpiece can be determined based on the dimensions, and the accuracy of the quality determination of the workpiece 2 can be improved.

  On the other hand, in a conventional image detection apparatus, an image of a workpiece photographed by an inspection apparatus is analyzed using pixels as determination targets, and indeterminate parts having scratches, foreign objects, etc. are discriminated in units of pixels, and the indefiniteness is determined. The quality of the work is determined based on how many pixels there are. For this reason, in the above-described conventional image detection apparatus, the pixel itself is the detection target as an indeterminate part, and thus the actual size (dimension) of the indeterminate part cannot be measured.

  Moreover, according to the image detection apparatus 6 according to the present embodiment, the extraction unit 64 that extracts an uncertain part such as a scratch or a foreign object from the difference image created by the creation unit 62 is provided. Of these, normal sites other than uncertain sites can be omitted. Furthermore, only the uncertain part can be a target of the quality determination of the workpiece 2, and the accuracy of the dimension calculation of the uncertain part by the dimension calculating unit 63 can be improved. Specifically, only the indeterminate part can be extracted and the image can be enlarged by the extraction unit 64, and the accuracy of the dimension calculation of the indeterminate part can be increased.

  In addition, since the brightness of the work image is varied as the shooting conditions can be varied, the exposure amount to the work image is different, and the color of the work image can be more clearly clarified. The boundary between the uncertain part and other parts can be further clarified.

  In addition, since the extraction unit 64 can also extract a portion with an uncertain maximum dimension from the difference image, the non-defective determination of the workpiece 2 can be easily performed by using the reference for determining the quality of the workpiece 2 as the uncertain portion with the maximum dimension. be able to.

  In addition, since the dimension calculated by the dimension calculator 63 is compared with a preset reference dimension and the quality determination unit 65 for determining the quality of the workpiece 2 is provided, it is suitable for mass production of the quality determination of the workpiece 2. is there.

  Further, the length dimension in the longitudinal direction of the uncertain part can be used as a criterion for determining the quality of the work 2, and in order to determine the non-defective product of the work 2 from the actual size (dimension) of the uncertain part. The accuracy of the quality determination of the work 2 can be improved.

  In addition, since the dimension of an uncertain part such as a scratch or a foreign object is the length dimension (major axis) in the longitudinal direction of the uncertain part, the dimension of the uncertain part can be accurately measured. The length dimension in the longitudinal direction of the fixed part can be used as a criterion for determining whether the workpiece 2 is good or bad. In addition, it is possible to meet the variety of criteria for determining the quality of the work 2 due to the presence of an uncertain part.

  In the present embodiment, the target of the dimension of the uncertain part such as a scratch or a foreign object is the length dimension (major axis) in the longitudinal direction of the uncertain part, but is not limited to this. The target of the dimension of the uncertain part may be the length dimension (minor axis) in the short direction, and the length dimension (major axis) of the indeterminate part and the length dimension in the short direction ( It is more preferable to target both dimensions of the minor axis.

  Specifically, the dimension calculation unit 63 calculates the length dimension (major axis) in the longitudinal direction and the dimension dimension (minor axis) in the short direction of uncertain parts such as scratches and foreign matters, By calculating the rectangular part composed of the length dimension (major axis) and the length dimension (minor axis) in the short direction, the length dimension in the longitudinal direction and the length dimension in the short direction of the uncertain part are calculated. The configured rectangular portion can be used as a criterion for determining the quality of the workpiece 2, and can respond to the variety of criteria for determining the quality of the workpiece 2 due to the presence of an indefinite portion.

  Further, as a specific example of the above-described dimensions, the length dimension in the longitudinal direction of the above-mentioned uncertain part is determined based on, for example, whether or not it is 20 μm or more. In the above case, the workpiece 2 having the uncertain part may be a defective product.

  In addition, based on whether or not the length dimension in the short direction of the uncertain part is 5 μm or more, for example, the length dimension in the short direction of the uncertain part is 5 μm or more. The work 2 having a fixed part may be a defective product.

  When the length dimension in the longitudinal direction or the short direction of these uncertain parts is calculated in units of pixels, the pixel has no concept of length and the length dimension must be calculated from the pixel area. The length dimension cannot be measured accurately. For example, the diagonal dimension of the pixel cannot be calculated.

  Further, whether or not the above-mentioned uncertain parts having a length dimension in the longitudinal direction of 10 μm or more are densely packed in a predetermined region may be used as a criterion for determining the quality of the workpiece.

  Further, as described above, according to the inspection apparatus 1 according to the present embodiment, since the image detection apparatus 6 according to the present embodiment is directly connected, the actual size of an indeterminate part having a scratch, a foreign object, or the like. (Dimension) can be measured, and the above-described effects of the image detection device 6 according to the present embodiment are obtained.

  Further, according to the inspection apparatus 1 according to the present embodiment, it is possible to determine whether the workpiece 2 is good or not without erroneous recognition even when the workpiece 2 is held by a holding mechanism such as the holding unit 5.

  In particular, according to the present embodiment, the image detection device 6 is directly or indirectly connected, and the photographing unit 4 and the illumination unit 3 are arranged via the work 2 held by the holding unit 5. 5, the photographing unit 4 and the illumination unit 3 are not provided in the same direction (position on the same side) with respect to the work 2 with reference to the work 2 held by the work 5. Therefore, the reflected light of the light irradiated on the work 2 (in the direction of the two-dot chain line in FIG. 1) and the reflected light reflected by the holding unit 5 holding the work 2 are not photographed by the photographing unit 4 and are reflected on the work 2. It is possible to find an indeterminate part including all attached or formed foreign matters (such as scratches, dust, and stains).

  In addition, according to the present embodiment, the photographing unit 4 and the illumination unit 3 are not provided in the same direction (position on the same side) with respect to the work 2 on the basis of the work 2 held by the holding unit 5. The holding unit 5 can be prevented from shining white due to the illumination from the illuminating unit 3, and erroneous recognition of the holding unit 5 as an uncertain part including a flaw or a foreign object due to white light emission can be prevented.

  In addition, a prevention plate 7 that is inclined with respect to the work 2 is provided at a position on the opposite side of the illumination unit 3 that faces the side on which the imaging unit 4 is arranged, and the imaging unit is interposed through the through hole 31. 4 and the prevention plate 7 face each other, so that the light reflected by the work 2 and the holding unit 5 can be prevented from being photographed by the photographing unit 4.

  Further, since the prevention plate 7 is a blackboard, the shooting area (field of view) in the shooting unit 4 can be made black.

  Further, since the light source unit 33 is a plurality of LEDs, the illumination life is long, there is no decrease in output, and stable illumination can be performed.

  In addition, since the imaging unit 4 is intended for imaging light having a wavelength shorter than that of red, a long wavelength such as red causes an ambiguous outline of an uncertain part including a scratch or a foreign object on a captured image by the imaging unit 4. It is possible to clearly photograph the foreign matter by the photographing unit 4 while suppressing the blurring (blurring).

  Further, in this embodiment, when determining the foreign matter, if the major axis is 20 μm or more, it is determined as a foreign matter. Therefore, by determining the foreign matter based on the size of an uncertain part including a scratch or a foreign matter, instead of determining the foreign matter by pixels, The accuracy of foreign object discrimination can be increased.

  Further, since the light source unit 33 irradiates the work 2 held by the holding unit 5 with directional light having an angle, the light from the illumination unit 3 does not directly irradiate the photographing unit 4 and the work 2. Even if light is applied to the workpiece 2, the workpiece 2 itself is not illuminated. Therefore, only when foreign matter exists in the work 2, an indeterminate part including scratches and foreign matters can be illuminated, and foreign matter can be easily confirmed.

  In addition, since the photographing by the photographing unit 4 is monochrome photographing, and the photographing unit 4 is intended for photographing a single wavelength light, the dimensions of uncertain parts including scratches and foreign matters are clearly defined even in the case of monochrome photographing. And the equipment cost can be reduced.

  In the present embodiment, the variable work image is an image obtained by performing image processing based on the image condition for changing the work image by the creation unit 62 from the work image acquired by the image acquisition unit 61, but is not limited thereto. Instead, the variable work image may be an image obtained by changing the shooting condition for shooting the work with respect to the work image, acquired by the image acquisition unit 61, and changing the image with respect to the work image. Note that the variable imaging condition here refers to “blurring” by changing (shifting) the focus of the work image.

  In the present embodiment, the present invention is applied to a filter which is an optical component as the workpiece 2 to be inspected. However, the present invention is not limited to this, and the inspection can be performed in the transmission type inspection apparatus 1 according to the present embodiment. Any other optical component (for example, an optical lens) may be used.

  In the present embodiment, the present invention is applied to a filter that is an optical component as the workpiece 2 to be inspected. However, the present invention is not limited to the optical component, and the inspection is performed in the transmission type inspection apparatus 1 according to the present embodiment. As long as it is a translucent material that can be used, for example, it may be a crystal wafer used for a crystal resonator or another component (work) such as a package of an electronic component, and the work 2 to be inspected is a piezoelectric material or a lens-based material. It is preferable that As described above, the work 2 to be inspected is made of a translucent material, and according to the present invention, not only the surface of the work 2 but also the contents can be detected. Is possible.

  In the present embodiment, the holding unit 5 is provided in the inspection apparatus 1, but the form of the holding unit is not limited to this, and the holding unit 5 is not fixedly provided in the inspection apparatus 1. Also, a holding unit provided in a transport device that transports the workpiece 2 to the inspection device 1 may be used. For example, a system in which the inspection apparatus 1 is provided as one of the manufacturing apparatuses for the work 2 is constructed, and in this system, the work 2 is provided in a transfer apparatus for transferring the work 2 to a plurality of manufacturing apparatuses including the inspection apparatus 1. It may be a holding part. That is, the holding unit 5 that holds the workpiece 2 only needs to be arranged between the illumination unit 3 and the photographing unit 4 so as to be fixed or movable.

  In this embodiment, the image detection device 6 is directly connected to the photographing unit 4 by wire, but the present invention is not limited to this, and the image detection device 6 is indirectly connected to the photographing unit 4 wirelessly. It may be connected.

  In this embodiment, a seamless zoom lens is used for the camera as a suitable example in order to enable inspection of the workpiece 2 of various sizes. However, the present invention is not limited to this, and a single-focus lens is used. It may be used.

  In this embodiment, the seamless zoom lens is used in the camera in order to cope with the inspection of the workpiece 2 of various sizes. However, the present invention is not limited to this, and a zoom lens having a preset magnification is simply used. It may be used.

  In this embodiment, a camera that performs monochrome photography is used for the purpose of reducing equipment costs, but the present invention is not limited to this, and a camera that performs color photography may be used.

  In the present embodiment, the holding unit 5 holds the workpiece 2 by pressing the side surface of the workpiece 2. However, the holding unit 5 is not limited to this, and may be a mechanism that can hold and hold the workpiece 2. For example, the outer peripheral side surface of the workpiece 2 may be sandwiched.

  In the present embodiment, a glossy blackboard is used for the prevention plate 7, but the present invention is not limited to this, and is set so that the light reflected by the work 2 and the holding unit 5 is not reflected in the photographing unit 4. For example, a mirror plate may be used as the prevention plate 7 in the dark field environment around the prevention plate 7. In the present embodiment, the prevention plate 7 is disposed at an inclination of about 45 degrees with respect to the holding portion 5 holding the workpiece 2, but is not limited thereto, and the workpiece 2 and the holding portion 5 are not limited thereto. The tilt angle may be set so that the light reflected at is not reflected on the photographing unit 4.

  In the present embodiment, the prevention plate 7 uses a blackboard in which an inclination angle is set so that light reflected by the work 2 and the holding unit 5 is not reflected on the photographing unit 4. The reflected light may be absorbed so that the reflected light is not reflected on the photographing unit 4.

  Further, in this embodiment, the plurality of LEDs are arranged in a plurality of upper and lower two rows, but the arrangement of the LEDs is not limited to this, and is a light source unit 33 having an annular shape in plan view. If the directivity from the LED is set so that the light emitted from the LED does not directly enter the lens of the camera of the photographing unit 4, other forms (other numbers or arrangements) may be used.

  In the present embodiment, the illumination unit 3 using LEDs as the light source unit 33 is provided in the inspection apparatus 1, but the light source unit 33 is not limited to this, and for example, a light source as shown in FIG. The illumination unit 3 using halogen as the unit 33 may be used.

  The illumination unit 3 shown in FIG. 16 uses halogen (not shown) that irradiates light to the light source unit 33 using a fiber guide (not shown). Further, in the illumination unit 3, an annular gap 35 is formed in the housing of the illumination unit 3 on the light path for irradiating light from the halogen onto the work 2 through the fiber guide. . In addition, you may provide the diffusion filter 34 shown in FIG. 2 in the illumination part 3 shown in this FIG.

  In the illuminating unit 3 shown in FIG. 16, a filter (not shown) for selecting (filtering) light from the light source unit 33 into light having a wavelength shorter than red is provided on the light path from the gap 35 or the halogen. It has been. In this case, even with a halogen that emits visible light including red, the external shape of the foreign matter can be clarified by selecting the wavelength. Furthermore, it is possible to clearly capture the foreign matter by the photographing unit 4 by suppressing the outline of the foreign matter of the photographed image by the photographing unit 4 from becoming ambiguous (blurred) due to the long wavelength such as red of visible light. it can. In this example, a filter is provided on the light path from the gap 35 or the halogen. However, the installation position of the filter is not limited to this, and may be before the light enters the imaging unit 4. Therefore, a filter may be provided in the photographing unit 4 (for example, immediately before the camera lens).

  It should be noted that the present invention can be implemented in various other forms without departing from the spirit, gist, or main features. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The image detection apparatus and inspection apparatus according to the present invention can be applied to inspection of translucent materials such as optical materials and electronic parts.

FIG. 1 is a schematic configuration diagram illustrating the relationship between the inspection apparatus and the image detection apparatus according to the present embodiment. FIG. 2 is a schematic perspective view of the illumination unit according to the present embodiment. FIG. 3 is a flowchart for detecting whether or not there is an indeterminate part by image processing using light in the image detection apparatus according to the present embodiment. FIG. 4 is a diagram showing an image of the workpiece in step S3 of the flowchart shown in FIG. FIG. 5 is a diagram showing an image of the workpiece in step S4 of the flowchart shown in FIG. FIG. 6 is a diagram showing an image of the workpiece in step S4 of the flowchart shown in FIG. FIG. 7 is a diagram showing an image of the workpiece in step S6 of the flowchart shown in FIG. FIG. 8 is a diagram showing an image of the workpiece in step S7 of the flowchart shown in FIG. FIG. 9 is a diagram showing an image of the workpiece in step S8 of the flowchart shown in FIG. FIG. 10 is a diagram showing an image of the workpiece in step S9 of the flowchart shown in FIG. FIG. 11 is a diagram showing an image of the workpiece in step S10 of the flowchart shown in FIG. FIG. 12 is an enlarged view of the blob selected in FIG. FIG. 13 is a diagram showing an image of the workpiece in step S19 of the flowchart shown in FIG. FIG. 14 is an enlarged view of the blob in FIG. FIG. 15 is a diagram showing an image of the workpiece in step S28 of the flowchart shown in FIG. FIG. 16 is a schematic configuration perspective view of an illumination unit according to another example of the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inspection apparatus 2 Workpiece | work 3 Illumination part 31 Through-hole 32 Inner wall surface 33 Light source part 35 Gap 4 Image pick-up part 5 Holding part 6 Image detection apparatus 61 Image acquisition part 62 Creation part 63 Size calculation part 64 Extraction part 65 Pass / fail judgment part 66 Display part 7 Prevention plate

Claims (11)

In an image detection apparatus that detects whether there is an uncertain part such as a scratch or a foreign object on a workpiece to be inspected by image processing using light,
An image acquisition unit for acquiring a work image of a work photographed by an external photographing device;
A creation unit that creates a difference image from a work image and a variable work image using a variable work image that is image-variable with respect to the work image acquired by the image acquisition unit;
An image detection apparatus, comprising: a dimension calculation unit that calculates a dimension of an uncertain part such as a scratch or a foreign object from the difference image created by the creation unit. The image detection apparatus according to claim 1,
The image detecting apparatus according to claim 1, wherein the variable work image is an image obtained by performing image processing based on an image condition for changing the work image by the creation unit from the work image acquired by the image acquisition unit. The image detection apparatus according to claim 1,
2. The image detecting apparatus according to claim 1, wherein the variable workpiece image is an image obtained by varying a photographing condition for photographing a workpiece with respect to the workpiece image, acquired by the image acquisition unit, and image-variable with respect to the workpiece image. The image detection apparatus according to any one of claims 1 to 3,
An image detection apparatus comprising: an extraction unit that extracts only uncertain parts such as scratches and foreign objects from the difference image created by the creation unit. The image detection apparatus according to claim 4,
An image detection apparatus characterized in that the extraction unit extracts an uncertain part such as a scratch of a maximum size or a foreign object. The image detection apparatus according to any one of claims 1 to 5,
The size of an uncertain part such as a scratch or a foreign object is at least one diameter of a length dimension in a longitudinal direction and a length dimension in a short direction of the uncertain part. The image detection apparatus according to claim 6.
The said dimension calculation part calculates the length dimension of the longitudinal direction of indeterminate parts, such as a crack and a foreign material, The image detection apparatus characterized by the above-mentioned. The image detection apparatus according to claim 6.
The dimension calculation unit calculates the length dimension in the longitudinal direction and the length dimension in the short direction of uncertain parts such as scratches and foreign matters, and the length dimension in the longitudinal direction and the length dimension in the short direction. An image detection apparatus characterized by calculating a rectangular part composed of: The image detection device according to any one of claims 1 to 8,
An image detecting apparatus characterized in that the workpiece is a translucent material. The image detection apparatus according to any one of claims 1 to 9,
An image detection apparatus, comprising: a pass / fail judgment unit for judging pass / fail of the workpiece by comparing the dimension calculated by the dimension calculation unit with a preset reference dimension. In inspection equipment that inspects workpieces to be inspected,
An illumination unit having an annular light source unit for illuminating the workpiece, and a photographing unit for photographing the workpiece;
The image detection device according to any one of claims 1 to 10 is connected directly or indirectly,
A holding unit for holding the workpiece is arranged between the illumination unit and the photographing unit so as to be fixed or movable,
The photographing unit is arranged at a position deviating from the irradiation direction of the light irradiated to the work from the light source unit of the illumination unit,
When there is an uncertain part such as a scratch or a foreign object on the work, the light irradiated to the work from the light source part is photographed by the photographing part with its optical path changed by the uncertain part. Inspection device to do.