JP2010237157A - Surface inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface inspecting device, capable of using a line sensor and detecting surface defects of an object to be inspected, with high accuracy. <P>SOLUTION: The surface inspecting device includes a conveyer 14 for conveying an object 12 to be inspected, an irradiating section 16 for irradiating to the surface of the object 12 conveyed by the conveyer 14 with a predetermined repeated light and darkness pattern; a power transmitting mechanism 18 for moving the light and darkness pattern irradiated to the object 12 in the width direction of the object 12; a line sensor 20 for imaging a section with the light and darkness pattern of the object 12 irradiated; and a defect determining section 50 for determining the presence of defects on the surface of the object 12, based on the signal imaged by the line sensor 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a surface inspection apparatus for detecting a surface defect of a subject.

  In products (subjects) such as various films (including those coated with a surface), magnetic tape, and glossy paper, irregular defects (surface defects) may occur on the surface in the manufacturing process.

  As an apparatus for detecting a surface defect of a subject, a device that irradiates a subject with a light and dark pattern, images the image, and detects a surface defect from distortion of the light and dark pattern is known (see Patent Document 1). . In this apparatus, a checkered pattern (checker pattern) or the like is described as an example of a light / dark pattern. It also describes that a line sensor is used as the imaging means. Further, it is described that in the case of a stripe pattern, the stage on which the subject is mounted is driven in a direction orthogonal to the line sensor element.

JP 2003-329428 A

  In the apparatus of Patent Document 1, when a pattern other than a stripe pattern is used as the type of light and dark pattern, it is necessary to capture it as a two-dimensional image with an area sensor. For this reason, it is necessary to keep the subject flat within the range of the image field of view, and it is not suitable for a subject (eg, a thin film) of a weak material that is prone to wrinkling, flapping, curling, and the like. Also, if the camera resolution is to be as high as that of a line sensor, the area sensor has a narrow field of view, making it difficult to achieve high sensitivity.

  On the other hand, as long as the relative position between the line sensor and the light / dark pattern is fixed in any light / dark pattern, the field of view of the line sensor is one line on the light / dark pattern, and the light reception signal is converted into a two-dimensional image. Sometimes there are only vertical stripes. In this way, if it is a light and dark pattern (one-dimensional stripe pattern) that becomes only a vertical stripe pattern when it is formed into a two-dimensional image, the stage can be driven and the line sensor can be used. A technique for holding a subject can be used. However, in this one-dimensional stripe pattern, when a defect (streaky defect) extending in a streak pattern in the transport direction is present on the surface of the subject, the amount of distortion on the image is determined by the positional relationship between the light and darkness of the stripe pattern and the defect. May vary greatly and may not be detected. As a result, the surface defect detection accuracy may be reduced.

  Therefore, an object of the present invention is to provide a surface inspection apparatus that uses a line sensor and can detect a surface defect of a subject with high accuracy.

  The surface inspection apparatus according to the present invention includes a transport unit that transports a subject, an irradiation unit that irradiates a surface of the subject transported by the transport unit with a predetermined repetitive light / dark pattern, and the subject. A moving means for moving the light / dark pattern in the width direction of the subject, a line sensor for picking up a portion of the subject irradiated with the light / dark pattern, and a signal picked up by the line sensor. The above-described problem is solved by including a defect determination unit that determines whether or not a defect exists on the surface of the specimen.

  According to the surface inspection apparatus of the present invention, since the light and dark pattern irradiated on the surface of the subject moves in the width direction of the subject, even when a streak defect in the transport direction exists on the surface of the subject, The streak defect is likely to straddle the light and dark pattern. Thereby, the distortion of the light and dark pattern by a surface defect can be displayed efficiently. Further, since the line sensor is used, the resolution of the camera can be increased as compared with the case where the area sensor is used. Therefore, the surface defect of the subject can be detected with high accuracy. In addition, since the presence or absence of the surface defect of the subject is determined by the defect determination unit, the subject having the surface defect can be excluded based on the determination result. Thereby, the product quality can be improved. Furthermore, if the surface inspection apparatus of the present invention is applied to a conveyance line in the manufacturing process, it is possible to detect the occurrence of surface defects at an early stage. This eliminates the concern of producing a large number of defective products.

  The surface inspection apparatus of the present invention is also applied to a subject (thin film) of a weak material that is prone to wrinkling, flapping, curling, and the like. In this case, the subject is a web, and the transport means is provided with a transport roll that rotates around a rotation axis extending in the width direction of the subject and transports the subject in the transport direction, The irradiating means may irradiate the light / dark pattern on an examination site in contact with the transport roll in the subject. According to this embodiment, since the subject (web) is held by the transport roll, wrinkles, flapping, curling, and the like are less likely to occur at the examination site of the subject. Thereby, even if the subject is a subject (thin film) made of a weak material, for example, it can be dealt with.

  In the above aspect, the irradiation unit corresponds to the light source unit that irradiates light to the inspection site, and the light / dark pattern that is positioned between the light source unit and the inspection site and that is applied to the inspection site. A light / dark display part having a pattern, and the moving means may move the pattern of the light / dark display part using a rotational force of the transport roll. According to this aspect, since the light output from the light source part is transmitted through the light / dark display part and guided to the examination part of the subject, the pattern on the light / dark display part is irradiated to the examination part as a light / dark pattern. Moreover, by moving the pattern of the light / dark display part, the light / dark pattern irradiated to the examination site can be moved in the width direction of the subject. Furthermore, by using the rotational force of the transport roll, it is possible to efficiently move the pattern on the light / dark display portion.

  In one form of the surface inspection apparatus of this invention, the said irradiation means is located between the light source part which irradiates light to the said test | inspection part, the said light source part, and the said test | inspection part, and is irradiated to the said test | inspection part. A light / dark display unit having a pattern corresponding to the light / dark pattern, and a drive unit that is provided separately from the drive source of the transport roll and moves the pattern of the light / dark display unit. The pattern of the light and dark display portion may be driven in synchronization with the rotation of the transport roll.

  When the transport roll and the light / dark display unit are driven by one drive source, it is necessary to simultaneously generate power necessary for the rotation of the transport roll and the movement of the pattern of the light / dark display unit by one drive source. According to this embodiment, since the drive unit is provided separately from the drive source of the transport roll, the power necessary for the rotation of the transport roll is the drive source of the transport roll and is necessary for the movement of the pattern of the light and dark display unit. The power can be dealt with by the drive unit. Thereby, compared with the case where a conveyance roll and a brightness-and-darkness display part drive with one drive source, each magnitude | size of the drive source and drive part of a conveyance roll can be reduced in size.

  In one form of the surface inspection apparatus of this invention, it further has the image process part which produces | generates a two-dimensional light-and-dark pattern image based on the signal imaged with the said line sensor, The said moving means conveys the said subject. The light / dark pattern irradiated on the subject may be moved in conjunction with the object. According to this aspect, since the light / dark pattern irradiated to the subject is moved in conjunction with the transportation of the subject, the image processing unit only arranges the signals imaged by the line sensor in time series (raster scan method). ), The position of the surface defect present on the subject can be associated with the position of the surface defect displayed on the two-dimensional light / dark pattern image. Thereby, when a surface defect is detected in the subject, the position of the defect can be easily specified.

  In the above aspect, the defect determination unit erases the light and dark pattern image obtained when the line sensor images the subject in a normal state from the light and dark pattern image generated by the image processing unit. It may be determined whether or not a defect exists on the surface of the subject. According to this aspect, the surface pattern is erased from the light / dark pattern image generated by the image processing unit when the normal state (no surface defect) subject is imaged by the line sensor. Only the distortion of the light and dark pattern due to the defect can be extracted. Thereby, the presence or absence of the surface defect of the subject can be easily determined.

  In one form of the surface inspection apparatus of this invention, the said defect determination part extracts the difference of the pixel which left | separated only predetermined distance in the brightness-and-darkness pattern image produced | generated in the said image process part, The surface of the said test object It may be determined whether or not there is a defect. In the light / dark pattern image generated by the image processing unit, the signal of the pixel located on the surface defect is different from the signal of the pixel located on the normal surface, so that the difference between pixels separated by a predetermined distance is extracted. Thus, it is possible to extract the distortion of the light and dark pattern due to the surface defect. This eliminates the need to previously create a light and dark pattern image obtained when a normal subject is imaged by the line sensor.

  In one form of the surface inspection apparatus of this invention, the said irradiation means is arrange | positioned in the position facing the said test | inspection site | part, and the video display which displays the pattern corresponding to the said light / dark pattern irradiated to the said test | inspection site | part as an image | video A video control unit that controls the video display unit so that the pattern displayed on the video display unit moves. According to this aspect, the pattern displayed on the video display unit is irradiated to the examination site as a bright and dark pattern. Further, by moving the pattern displayed on the video display unit by the video control unit, the light / dark pattern irradiated on the examination site can be easily moved in the width direction of the subject.

  In the above embodiment, the image processing unit further includes an image processing unit that generates a two-dimensional light / dark pattern image based on a signal captured by the line sensor, and the defect determination unit includes the light / dark pattern generated by the image processing unit. Whether or not a defect exists on the surface of the subject may be determined based on an image and a pattern displayed on the video display unit. According to this embodiment, the pattern displayed on the video display unit can be used for determining the presence or absence of surface defects. Thereby, the presence or absence of the surface defect of the subject can be easily determined.

  As described above, according to the surface inspection apparatus of the present invention, since the light / dark pattern irradiated on the surface of the subject moves in the width direction of the subject, the distortion of the light / dark pattern due to the surface defect is efficiently displayed. be able to. Further, since the line sensor is used, the resolution of the camera can be increased as compared with the case where the area sensor is used. Therefore, the surface defect of the subject can be detected with high accuracy.

It is a figure which shows the principal part of the surface inspection apparatus which concerns on 1st Embodiment. It is a figure which shows the flowchart which concerns on a 1st control routine. It is a figure which shows the light-dark pattern image obtained when the subject which has a point defect is imaged with a line sensor. It is a figure which shows the light-dark pattern image obtained when the subject which has the streak defect of a conveyance direction is imaged with a line sensor. It is a figure which shows the principal part of the surface inspection apparatus which concerns on 2nd Embodiment. It is a figure which shows the flowchart which concerns on a 2nd control routine. It is a figure which shows the principal part of the surface inspection apparatus which concerns on 3rd Embodiment. It is a figure which shows the flowchart which concerns on a 3rd control routine.

  Hereinafter, embodiments of the surface inspection apparatus according to the present invention will be described with reference to FIGS.

(First embodiment)
First, a surface inspection apparatus (first inspection apparatus) 10 according to the first embodiment is an apparatus for detecting uneven defects (surface defects) existing on the surface of a subject. Incorporated into the in-process transport line.

  The first inspection apparatus 10 includes a transport unit 14 that transports the subject 12, an irradiation unit 16, a power transmission mechanism 18, a line sensor 20, and a control unit 22. As the object 12, for example, various films (including those coated with a surface), magnetic tape, glossy paper, and the like are used. The subject 12 is configured as a web.

  The transport unit 14 includes a transport roll 24 that rotates around a rotation axis that extends in the width direction of the subject 12 (the direction of arrow A in FIG. 1), and a transport motor 25 that rotationally drives the transport roll 24. The transport roll 24 transports the subject 12 in the transport direction. The subject 12 is set so as to be wound around the transport roll 24.

  The irradiating unit 16 irradiates the examination site X in contact with the transport roll 24 in the subject 12 with a light / dark pattern. The irradiation unit 16 includes a light source unit 26 and a light / dark display unit 28.

  The light source unit 26 includes a light source box 30 containing a lamp (not shown) and a rod unit 32 connected to the light source box 30 and extending in the width direction of the subject 12. That is, the light source unit 26 is configured as so-called rod illumination. The lamp enters light into the rod portion 32. The rod portion 32 emits light incident from the lamp in a line shape. The rod portion 32 is disposed at a position facing the examination site X of the subject 12. The rod portion 32 is formed such that its length in the longitudinal direction is somewhat larger than the width of the subject 12.

  The light / dark display section 28 includes a rotating cylindrical body 34 that covers the periphery of the rod section 32 in a state of extending in the width direction of the subject 12, and a support section 36 that rotates integrally with the rotating cylindrical body 34. A predetermined repeated bright and dark pattern is formed on the outer peripheral surface of the rotating cylindrical body 34. As the light / dark pattern, a light / dark pattern (inclined stripe pattern) in the direction intersecting the width direction and the transport direction of the subject 12 is used. The light / dark pattern is configured such that transparent portions 38 that transmit light emitted from the rod portion 32 and light shielding portions 40 that shield light emitted from the rod portion 32 are alternately arranged. The diameters of the rotating cylindrical body 34 and the support portion 36 are set to be substantially the same as the diameter of the transport roll 24.

  The power transmission mechanism 18 transmits the rotational force of the transport roll 24 to the support unit 36. As the power transmission mechanism 18, a V belt or the like wound around the transport roll 24 and the support portion 36 is used. As a result, the support portion 36 rotates in conjunction with the rotation of the transport roll 24.

  The line sensor 20 is configured as a camera that images the examination site X of the subject 12. The line sensor 20 is set so that its visual field includes the entire width of the subject 12. The focus of the line sensor 20 is adjusted to the light / dark pattern irradiated to the inspection site X with the inspection site X as a reflection surface. The imaging signal imaged by the line sensor 20 is output in real time as a digital signal.

  The control unit 22 controls the light source box 30, the transport motor 25, and the line sensor 20. The control unit 22 includes a light source control unit 42, a timing generation unit 43, a transport motor control unit 44, a line sensor control unit 45, an image processing unit 46, a storage unit 48, and a defect determination unit 50.

  The light source control unit 42 adjusts the light that enters the rod unit 32 by turning on the lamp.

  The timing generator 43 outputs a timing signal for taking the timing of the transport operation of the subject 12 and the imaging operation of the line sensor 20 based on the clock signal. Specifically, the timing generation unit 43 outputs a conveyance timing signal to the conveyance motor control unit 44 and outputs a line sensor timing signal to the line sensor control unit 45.

  The transport motor controller 44 drives the transport motor 25 based on the transport timing signal output from the timing generator 43 and rotates the transport roll 24.

  The line sensor control unit 45 operates the line sensor 20 based on the line sensor timing signal output from the timing generation unit 43, and images the light / dark pattern irradiated to the examination region X.

  The image processing unit 46 generates a two-dimensional light / dark pattern image based on the imaging signal output from the line sensor 20.

  The storage unit 48 stores a determination light / dark pattern image. As the light / dark pattern image for determination, an image corresponding to the light / dark pattern image generated based on the imaging signal of the line sensor 20 when the inspection region X of the subject 12 in the normal state (the surface defect is absent) is used. It is done.

  The defect determination unit 50 determines whether or not a surface defect exists in the inspection site X of the subject 12 based on the light / dark pattern image generated by the image processing unit 46 and the light / dark pattern image for determination.

  Next, the operation of the first inspection apparatus 10 will be described with reference to the flowchart relating to the first control routine of FIG. The first control routine is repeatedly executed at a predetermined cycle.

  First, the light source control unit 42 turns on the lamp and makes light enter the rod portion 32 (step S1). When the lamp irradiates light into the rod portion 32, linear light is emitted from the rod portion 32. Of the light emitted from the rod portion 32, the light guided to the transparent portion 38 of the rotating cylindrical body 34 is transmitted, and the light guided to the light shielding portion 40 of the rotating cylindrical body 34 is shielded. That is, only the light that has passed through the transparent portion 38 is irradiated on the examination site X of the subject 12. As a result, the light-dark pattern formed on the rotating cylindrical body 34 is irradiated onto the examination site X of the subject 12.

  Thereafter, the transport motor control unit 44 drives the transport motor 25 to rotate the transport roll 24 (step S2). When the transport roll 24 rotates, the subject 12 is transported in the transport direction. At this time, the rotational force of the transport roll 24 is transmitted to the support portion 36 via the power transmission mechanism 18, and the rotating cylindrical body 34 rotates in the same direction as the transport roll 24. When the rotating cylinder 34 rotates, the inclined stripe pattern formed on the rotating cylinder 34 also rotates, so that the light / dark pattern irradiated to the examination site X moves in the width direction of the subject 12.

  Further, the line sensor control unit 45 operates the line sensor 20 to image the light / dark pattern irradiated on the examination site X (step S3).

  Thereafter, the image processing unit 46 generates a light / dark pattern image based on the imaging signal output from the line sensor 20 (step S4). The image processing unit 46 generates a two-dimensional light / dark pattern image by a so-called raster scan method. That is, the image processing unit 46 generates a light and dark pattern image by arranging the imaging signals (line signals) captured by the line sensor 20 in time series. At this time, since the light / dark pattern irradiated to the examination region X moves in the width direction of the subject 12, the light / dark pattern image generated by the image processing unit 46 becomes an inclined stripe pattern image. Note that the image signal captured by the line sensor 20 is sent to the image processing unit 46 in real time. Further, for example, when there is a circular point defect (such as a pressing defect having a concave surface or a convex defect due to internal foreign matter) on the surface of the subject 12, the reflection angle at the point defect is a normal surface ( Therefore, the bright / dark pattern image generated by the image processing unit 46 is distorted on the point defect (see FIG. 3). Similarly, when a streak defect in the transport direction exists on the surface of the subject 12, the light and dark pattern image generated by the image processing unit 46 is distorted on the streak defect (see FIG. 4). .

  Thereafter, the defect determination unit 50 determines whether or not a surface defect exists in the inspection site X of the subject 12 based on the light / dark pattern image generated by the image processing unit 46 and the light / dark pattern image for determination. (Step S5). Specifically, the defect determination unit 50 erases the determination light / dark pattern image from the light / dark pattern image. Thereby, only the distortion of the light and dark pattern by a surface defect can be extracted. Then, the defect determination unit 50 determines that the surface defect does not exist when the image does not exist after erasure, and determines that the surface defect exists when the image exists after the erasure. To do. The control unit 22 repeatedly executes this process when the defect determination unit 50 determines that no surface defect exists. This repeated processing period may be set as appropriate. On the other hand, the control routine proceeds to step S6 when the defect determination unit 50 determines that a surface defect exists.

  Then, the control part 22 stops the drive of the conveyance motor 25, and stops rotation of the conveyance roll 24 (step S6). After the process of step S6, the current control routine ends.

  In the surface inspection apparatus 10 of the present embodiment, since the light / dark pattern irradiated to the inspection site X moves in the width direction of the subject 12, even when a streak defect in the transport direction exists on the surface of the subject 12, The streak defect is likely to straddle the light and dark pattern. Therefore, in the light / dark pattern image generated based on the image signal picked up by the line sensor 20, the light / dark pattern distortion due to the streak defect can be efficiently displayed. Therefore, when the defect determination unit 50 erases the determination light / dark pattern image from the light / dark pattern image, distortion due to the streak defect can be efficiently left. In addition, since the line sensor 20 is used, the resolution of the camera can be increased as compared with the case where the area sensor is used. Therefore, the surface defect of the subject 12 can be detected with high accuracy.

  Moreover, since the control part 22 stops rotation of the conveyance roll 24, when the defect determination part 50 determines with the surface defect existing, a defective product can be excluded. Thereby, the product quality can be improved. Furthermore, since the first inspection apparatus 10 is incorporated in the conveyance line during the manufacturing process, the occurrence of surface defects can be detected at an early stage. This eliminates the concern of producing a large number of defective products.

  The first inspection apparatus 10 is also applied to a subject (thin film) 12 of a low-skin material that is likely to be wrinkled, fluttered, or curled. In this embodiment, since the subject (web) 12 is held by the transport roll 24, wrinkles, fluttering, curling, and the like are less likely to occur at the examination site X of the subject 12. Thereby, even if the subject 12 is a thin film (a material having a weak waist), it can be dealt with.

  Further, in this embodiment, since the rotating cylindrical body 34 is rotated by using the rotational force of the transport roll 24, the light / dark pattern irradiated to the examination site X can be efficiently moved.

  Furthermore, in this embodiment, a V-belt is used as the power transmission mechanism 18 and the diameter of the transport roll 24 and the diameter of the support portion 36 are set to be approximately the same. The moving speed of the bright and dark pattern irradiated to the can be made substantially the same. As a result, the aspect ratio of the light / dark pattern image generated by the image processing unit 46 is the same as the aspect ratio of the image obtained when the image is captured using the area sensor. That is, the position of the surface defect present on the subject 12 can be associated with the position of the surface defect displayed on the light / dark pattern image. Thereby, when a surface defect is detected in the subject 12, the position of the defect can be easily specified.

  The first embodiment is not limited to the above-described embodiment. The light source unit is not limited to the example using rod illumination, and may use a fluorescent lamp or other lighting fixtures. The power transmission mechanism may use a chain or a gear mechanism instead of the V-belt. The rotation of the light / dark display unit is not limited to the configuration using the rotational force of the transport roller. For example, a power transmission mechanism may be omitted, and a new rotation motor that rotationally drives the support portion may be added. In this case, you may set arbitrarily the rotational speed of a support part.

(Second Embodiment)
Next, a surface inspection apparatus (second inspection apparatus) 100 according to a second embodiment will be described with reference to FIG. Note that, in the second embodiment, the same reference numerals are assigned to configurations common to the first embodiment, and description thereof is omitted.

  In the second inspection apparatus 100, the configurations of the irradiation unit 16 and the control unit 22 in the first inspection apparatus 10 are different, and the power transmission mechanism 18 is omitted.

  The irradiation unit 116 has an image display unit 52 that is disposed at a position facing the examination site X and extends in the width direction of the subject 12 (the direction of arrow A in FIG. 5). As the image display unit 52, for example, a liquid crystal display or the like is used. The video display unit 52 includes a display unit 54 that displays a predetermined repetitive brightness pattern as a video. As the light / dark pattern, a light / dark pattern (stripe pattern) in the width direction of the subject 12 is used. The length in the longitudinal direction of the display unit 54 is set to be approximately the same as the width of the subject 12.

  The control unit 122 also controls the video display unit 52. In the control unit 122, the light source control unit 42 and the storage unit 48 of the first inspection apparatus 10 are omitted, and a video control unit 56 and a comparison image processing unit 58 are added.

  The timing generation unit 143 outputs the above-described conveyance timing signal and line sensor timing signal based on the clock signal, and outputs a video timing signal to the video control unit 56. Thereby, the timing of the conveyance operation of the subject 12, the imaging operation of the line sensor 20, and the movement operation of the light / dark pattern can be taken.

  The video control unit 56 moves the light / dark pattern displayed on the video display unit 52 in the width direction of the subject 12 based on the video timing signal output from the timing generation unit 143. The moving speed of the light / dark pattern and the transport speed of the subject 12 may be set to be substantially the same.

  The comparison image processing unit 58 generates a comparison light / dark pattern image. Specifically, the comparative image processing unit 58 acquires the shape information of the light and dark pattern displayed on the video display unit 52 from the video control unit 56, and takes into account correction of the optical system, and then the subject 12 in a normal state. A two-dimensional light / dark pattern image that should be obtained when the light / dark pattern irradiated to the inspection site X is imaged by the line sensor 20 is generated as a comparative light / dark pattern image.

  Further, the defect determination unit 150 determines whether or not a surface defect exists in the inspection site X of the subject 12 based on the light / dark pattern image generated by the image processing unit 46 and the comparative light / dark pattern image. .

  Next, the operation of the second inspection apparatus 100 will be described with reference to the flowchart relating to the second control routine of FIG. In the second control routine, the processes of steps S1 and S5 of the first control routine are changed. Therefore, description of processing common to the first control routine is omitted.

  First, in step S <b> 21, the control unit 122 inputs power for the video display unit 52. As a result, a light / dark pattern is displayed on the display unit 54 of the video display unit 52. At this time, the video control unit 56 moves the light / dark pattern displayed on the video display unit 52.

  In step S <b> 25, the defect determination unit 150 determines whether a surface defect exists in the subject 12 based on the light / dark pattern image generated by the image processing unit 46 and the comparative light / dark pattern image. . Specifically, the defect determination unit 150 compares the light / dark pattern image generated by the image processing unit 46 with the comparative light / dark pattern image, and extracts a defect by analyzing the difference.

  In the second inspection apparatus 100 of the present embodiment, the light / dark pattern displayed on the video display unit 52 is irradiated to the inspection site X of the subject 12. In addition, by moving the light / dark pattern displayed on the video display unit 52 by the video control unit 56, the light / dark pattern irradiated on the examination site X can be easily moved in the width direction of the subject 12.

  In this embodiment, the light / dark pattern image displayed on the video display unit 52 at the time of defect determination can be used as a comparative light / dark pattern. Therefore, it is not necessary to preliminarily create a comparative light / dark pattern image by imaging the inspection site X of the subject 12 in a normal state with the line sensor 20.

(Third embodiment)
Next, a surface inspection apparatus (third inspection apparatus) 200 according to a third embodiment will be described with reference to FIG. In the third embodiment, the same reference numerals are assigned to the same components as those in the first embodiment, and description thereof is omitted.

  In the third inspection apparatus 200, the configuration of the irradiation unit 16 in the first inspection apparatus 10 is different, and the power transmission mechanism 18 is omitted.

  The irradiation unit 216 includes a light source unit 226 and a light / dark display unit 228.

  The light source unit 226 includes a fluorescent unit 70 disposed at a position facing the examination site X of the subject 12, a cable unit 72 connected to the fluorescent unit 70, and is connected to the cable unit 72 to supply power to the fluorescent unit 70. And a power supply unit 74 for supply. The fluorescent part 70 extends in the width direction of the subject 12 and irradiates light in a line shape.

  The light / dark display portion 228 includes a belt portion 76 that extends in the width direction of the subject 12 and is positioned between the subject 12 and the fluorescent portion 70, and a belt drive support portion 78 that supports the belt portion 76. The belt portion 76 is made of a material that blocks light, and is made of, for example, metal or rubber. Further, an endless belt can be used as the belt portion 76. A plurality of hole portions 80 are formed in the belt portion 76 so as to be aligned in the width direction of the subject 12. These hole portions 80 are formed in the longitudinal direction in the width direction of the belt portion 76. Thereby, the light irradiated from the fluorescent part 70 is irradiated to the examination site X of the subject 12 through the hole 80 of the belt part 76. Therefore, a bright and dark pattern is formed in the inspection site X. The belt drive support portion 78 is disposed at a position facing the drive shaft 82, a drive shaft 82 that moves the belt portion 76 in the longitudinal direction, a drive motor 84 as a drive portion for rotating the drive shaft 82, and the drive shaft 82. And a support shaft 86 that supports the belt portion 76. Further, the drive shaft 82 and the support shaft 86 are disposed so as to extend the belt portion 76 from the inside to the outside. Thereby, it can prevent that the belt part 76 bends. The support shaft 86 is configured to be rotatable by the rotational force of the drive shaft 82 transmitted through the belt portion 76.

  The control unit 222 also controls the drive motor 84. A drive motor control unit 88 that controls the drive motor 84 is added to the control unit 222.

  The timing generator 243 outputs the above-described transport timing signal and line sensor timing signal based on the clock signal, and also outputs a drive timing signal to the drive motor controller 88. Thereby, the timing of the conveyance operation of the subject 12, the imaging operation of the line sensor 20, and the movement operation of the belt portion 76 can be taken.

  The drive motor control unit 88 drives the drive motor 84 based on the drive timing signal output from the timing generation unit 243 and moves the belt unit 76.

  Next, the operation of the third inspection apparatus 200 will be described with reference to the flowchart relating to the third control routine of FIG. In the third control routine, the processes of step S2 and step S6 of the first control routine are changed, and description of processes common to the other first control routines is omitted.

  In step S32 following step S31, in addition to the conveyance motor control unit 44 driving the conveyance motor 25 to rotate the conveyance roll 24, the drive motor control unit 88 drives the drive motor 84 to rotate the drive shaft 82. Let When the drive shaft 82 rotates, the belt portion 76 moves in the width direction of the subject 12. As a result, the light / dark pattern irradiated on the examination site X moves in the width direction of the subject 12. Then, the line sensor control unit 45 operates the line sensor 20 to image the light / dark pattern irradiated on the examination site X (step S33), and the image processing unit 46 is based on the imaging signal output from the line sensor 20. Then, a bright / dark pattern image is generated (step S34). The defect determination unit 50 determines whether or not a surface defect exists in the inspection site X of the subject 12 based on the light / dark pattern image generated by the image processing unit 46 and the light / dark pattern image for determination (step) S35) When it is determined that a surface defect exists, in subsequent step S36, the control unit 222 stops driving the transport motor 25 and the drive motor 84, and rotates the transport roll 24 and the belt unit 76. Stop moving. After the process of step S36, the current control routine ends.

  When the transport roll and the light / dark display unit are driven by one drive source, it is necessary to simultaneously generate power necessary for the rotation of the transport roll and the movement of the pattern of the light / dark display unit by one drive source. In the surface inspection apparatus 300 according to this embodiment, since the conveyance motor 25 and the drive motor 84 are provided, the power necessary for the rotation of the conveyance roll 24 is the conveyance motor 25 and the rotation of the drive shaft 82 (pattern of the light / dark display portion 228). The driving motor 84 can handle the power required for the movement of Thereby, compared with the case where the conveyance roll 24 and the brightness-and-darkness display part 228 are driven with one drive source, each magnitude | size of the conveyance motor 25 and the drive motor 84 can be reduced in size.

  The present invention is not limited to the above embodiment, and can be implemented in various forms. The light / dark pattern of the surface inspection apparatus according to the present invention is not limited to the inclined stripe pattern or the stripe pattern. For example, any two-dimensional pattern such as a checkered pattern (checker pattern), a lattice shape, or a hexagonal shape can be used as the light and dark pattern. The defect determination unit is not limited to an example in which it is determined whether or not a surface defect exists based on the light / dark pattern image generated by the image processing unit and the determination (comparison) light / dark pattern image. The defect determination unit may determine whether or not a defect exists on the surface of the subject by extracting a difference between pixels separated by a predetermined distance in the light and dark pattern image generated by the image processing unit. . In this case, in the light and dark pattern image generated by the image processing unit, the signal of the pixel located on the surface defect is different from the signal of the pixel located on the normal surface. By extracting, it is possible to extract the distortion of the light and dark pattern due to the surface defect. Thereby, it is not necessary to generate a determination (comparison) light / dark pattern image.

DESCRIPTION OF SYMBOLS 10, 100, 200 ... Surface inspection apparatus 12 ... Subject 14 ... Conveyance part (conveyance means)
16, 116, 216 ... Irradiation part (irradiation means)
18 ... Power transmission mechanism (moving means)
DESCRIPTION OF SYMBOLS 20 ... Line sensor 22, 122, 222 ... Control part 24 ... Conveyance roll 26, 226 ... Light source part 28, 228 ... Brightness / darkness display part 46 ... Image processing part 50, 150 ... Defect determination part 52 ... Video display part 56 ... Video control (Moving means)
84 ... Drive motor (drive unit)
X ... Test site

Claims (9)

Transport means for transporting the subject;
Irradiating means for irradiating a predetermined repetitive light / dark pattern on the surface of the subject conveyed by the conveying means;
Moving means for moving the light / dark pattern irradiated to the subject in the width direction of the subject;
A line sensor that images the region irradiated with the light-dark pattern of the subject;
A surface inspection apparatus comprising: a defect determination unit that determines whether a defect exists on the surface of the subject based on a signal imaged by the line sensor. The surface inspection apparatus according to claim 1,
The subject is a web;
The transport means is provided with a transport roll that rotates around a rotation axis extending in the width direction of the subject and transports the subject in the transport direction,
The surface inspection apparatus characterized in that the irradiation means irradiates the light / dark pattern to an inspection site in contact with the transport roll in the subject. In the surface inspection apparatus according to claim 2,
The irradiation means includes a light source unit that irradiates light to the examination site;
A light and dark display part located between the light source part and the examination part and having a pattern corresponding to the light and dark pattern irradiated to the examination part; and
The surface inspection apparatus characterized in that the moving means moves the pattern of the brightness / darkness display portion using the rotational force of the transport roll. In the surface inspection apparatus according to claim 2,
The irradiation means includes a light source unit that irradiates light to the examination site;
A light / dark display part located between the light source part and the examination part and having a pattern corresponding to the light / dark pattern irradiated to the examination part;
A drive unit that is provided separately from the drive source of the transport roll and moves the pattern of the light and dark display unit; and
The surface inspection apparatus, wherein the driving unit drives the pattern of the light and dark display unit in synchronization with the rotation of the transport roll. In the surface inspection apparatus according to any one of claims 1 to 4,
An image processing unit that generates a two-dimensional light and dark pattern image based on a signal imaged by the line sensor;
The surface inspection apparatus, wherein the moving means moves the light / dark pattern irradiated to the subject in conjunction with transport of the subject. The surface inspection apparatus according to claim 5,
The defect determination unit erases a light / dark pattern image obtained when the line sensor images the object in a normal state from the light / dark pattern image generated by the image processing unit. It is determined whether or not a defect exists in the surface inspection apparatus. The surface inspection apparatus according to claim 5,
The defect determination unit determines whether or not a defect exists on the surface of the subject by extracting a difference between pixels separated by a predetermined distance in the light and dark pattern image generated by the image processing unit. A surface inspection apparatus characterized by that. In the surface inspection apparatus according to claim 2,
The irradiation means is provided with a video display unit that is arranged at a position facing the inspection site and displays a pattern corresponding to the light and dark pattern irradiated to the inspection site as an image,
The surface inspection apparatus according to claim 1, wherein the moving means is provided with a video control unit that controls the video display unit so that a pattern displayed on the video display unit moves. The surface inspection apparatus according to claim 8, wherein
An image processing unit that generates a two-dimensional light and dark pattern image based on a signal imaged by the line sensor;
The defect determination unit determines whether a defect exists on the surface of the subject based on a light / dark pattern image generated by the image processing unit and a pattern displayed on the video display unit. Surface inspection device characterized by.

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