[go: up one dir, main page]

WO2013012106A1 - Caméra pour détecter des défauts d'une surface métallique, dispositif incluant la caméra pour détecter des défauts d'une surface métallique et procédé pour détecter des défauts d'une surface métallique - Google Patents

Caméra pour détecter des défauts d'une surface métallique, dispositif incluant la caméra pour détecter des défauts d'une surface métallique et procédé pour détecter des défauts d'une surface métallique Download PDF

Info

Publication number
WO2013012106A1
WO2013012106A1 PCT/KR2011/005282 KR2011005282W WO2013012106A1 WO 2013012106 A1 WO2013012106 A1 WO 2013012106A1 KR 2011005282 W KR2011005282 W KR 2011005282W WO 2013012106 A1 WO2013012106 A1 WO 2013012106A1
Authority
WO
WIPO (PCT)
Prior art keywords
metal object
light source
light
wavelength
linearly polarized
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/KR2011/005282
Other languages
English (en)
Korean (ko)
Inventor
장유진
이주섭
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEDTECH CO Ltd
Industry Academic Cooperation Foundation of Dongguk University
Original Assignee
NEDTECH CO Ltd
Industry Academic Cooperation Foundation of Dongguk University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEDTECH CO Ltd, Industry Academic Cooperation Foundation of Dongguk University filed Critical NEDTECH CO Ltd
Publication of WO2013012106A1 publication Critical patent/WO2013012106A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/8806—Specially adapted optical and illumination features
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/30—Measuring arrangements characterised by the use of optical techniques for measuring roughness or irregularity of surfaces
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/21—Polarisation-affecting properties
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/8806—Specially adapted optical and illumination features
    • G01N2021/8845—Multiple wavelengths of illumination or detection
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
    • G01N21/8914—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles characterised by the material examined
    • G01N2021/8918—Metal

Definitions

  • the present invention relates to a camera system for detecting metal surface defects, and more particularly, to a camera for metal surface defect detection, a metal surface defect detection apparatus including the camera, and a metal surface defect detection method.
  • a method of detecting surface defects of a steel plate moving at a high speed includes a method of detecting surface defects by observing a surface of a steel plate being moved directly by an operator, and irradiating a laser light source to the surface and receiving a laser light receiving unit.
  • a laser light source to the surface and receiving a laser light receiving unit.
  • To detect surface defects through constant signal processing and to irradiate the surface of the steel sheet with illumination in the visible light region, to receive it with a line scan camera, and to detect surface defects through constant signal processing. There may be.
  • the defect detection method based on the operator's observation may be difficult to objectively detect because it is difficult to have consistent detection criteria among workers. Detecting defects using lasers can be susceptibly affected by external conditions, such as minor vibrations of continuously moving steel sheets.
  • the technical problem to be solved by the present invention relates to a metal surface defect detection technique and system, a surface for obtaining an image by simultaneously irradiating a stationary or moving metal surface with linearly polarized illumination without interference and orthogonal to each other
  • a camera for defect detection, a metal surface defect detection apparatus including the camera, and a metal surface defect detection method are provided.
  • the camera according to the embodiment of the present invention when irradiating the surface of the metal object with the linearly polarized lights (horizontal wave and longitudinal wave) without interference and orthogonal to each other at the same time, the reflection on the surface of the metal object A polarization separator that separates the divided light into vertical polarization (longwave) and horizontal polarization (horizontal wave); A first charge coupled device obtaining an image of the vertical polarization; And a second charge coupling device for acquiring the image of the horizontal polarization.
  • the polarizer may be a polarizing beamsplitter cube.
  • the metal surface defect detection apparatus for irradiating the surface of the metal object with linearly polarized light in bright field conditions;
  • a camera for acquiring the light reflected from the surface of the metal object to acquire an image for inspecting the surface defect of the metal object.
  • the camera may include a polarization separator that separates light reflected from the surface of the metal object into vertical polarization (longwave) and horizontal polarization (horizontal wave) when the linearly polarized lights are irradiated on the surface of the metal object; A first charge coupled device obtaining the image of the vertical polarization; And a second charge coupling device for acquiring the image of the horizontal polarization.
  • the metal object may be a stationary metal object or a moving metal object.
  • the first light source for irradiating the surface of the metal object with linearly polarized light of the first wavelength in bright field conditions;
  • a second light source for irradiating a surface of the metal object with linearly polarized light having a second wavelength under dark field conditions;
  • a third light source for irradiating a surface of the metal object with a linearly polarized light having a second wavelength orthogonal to the linearly polarized light of the second wavelength in a dark field condition;
  • a fourth light source for irradiating the surface of the metal object with illumination of the linearly polarized first wavelength orthogonal to the linearly polarized illumination of the first wavelength in dark field conditions;
  • a camera unit which acquires the light reflected from the surface of the metal object to acquire an image for inspecting the surface defect of the metal object, wherein the first light source, the second light source, the third light source, and the The fourth light source can illuminate the lights at the
  • the camera unit is disposed between the first light source and the fourth light source, and between the second light source and the third light source, wherein the first light source and the fourth light source are disposed with respect to the second light source and the third light source. It may be arranged to be orthogonal.
  • the camera unit reflects from the surface of the metal object when the illumination of the first light source, the illumination of the second light source, the illumination of the third light source, and the illumination of the fourth light source are simultaneously irradiated onto the surface of the metal object.
  • a color screening mirror that separates the light into the light of the first wavelength and the light of the second wavelength;
  • a first camera that obtains light of a first wavelength separated from the color-dividing mirror into vertical and horizontal polarizations, and acquires an image for inspecting surface defects of the metal object by using the obtained vertical and horizontal polarizations ;
  • a second light obtained by separating light having a second wavelength separated from the color-dividing mirror into vertical polarization and horizontal polarization and acquiring an image for inspecting surface defects of the metal object by using the obtained vertical polarization and horizontal polarization. It may include a camera.
  • the first light source for irradiating the surface of the metal object with linearly polarized light of the first wavelength at a first angle;
  • a second light source for irradiating a surface of the metal object with linearly polarized light having a second wavelength at a second angle;
  • a third light source for irradiating a surface of the metal object with the linearly polarized light of the second wavelength orthogonal to the linearly polarized light of the second wavelength at a third angle;
  • a fourth light source for irradiating the surface of the metal object with the linearly polarized light of the first wavelength orthogonal to the linearly polarized light of the first wavelength at a fourth angle;
  • a camera unit which acquires the light reflected from the surface of the metal object to acquire an image for inspecting the surface defect of the metal object, wherein the first light source, the second light source, the third light source, and the The fourth light source irradiates
  • the metal surface defect detection method (a) irradiating the surface of the metal object with linearly polarized light in bright field conditions; (b) irradiating the surface of the metal object at the same time as the irradiation of the linearly polarized light in the bright field conditions orthogonal to the linearly polarized light in the dark field conditions and having the same wavelength as the wavelength of the linearly polarized light; Doing; (c) simultaneously acquiring an image of light reflected from the surface of the metal object; And (d) signal processing the obtained image to detect surface defects of the metal object.
  • a metal surface defect detection method (a) irradiating the surface of the metal object with a linearly polarized light of the first wavelength at a first angle; (b) irradiating a surface of the metal object with linearly polarized light of a second wavelength at a second angle; (c) irradiating a surface of the metal object with a linearly polarized light of a second wavelength orthogonal to the linearly polarized light of the second wavelength at a third angle; (d) irradiating a surface of the metal object with linearly polarized light of a first wavelength orthogonal to the linearly polarized light of the first wavelength at a fourth angle; (e) simultaneously acquiring an image of light reflected from the surface of the metal object; And (f) signal processing the obtained image to detect surface defects of the metal object, wherein the illumination of the first wavelength and the illumination of the second wavelength are simultaneously irradiated and the first angle
  • a camera for detecting metal surface defects according to the present invention a device for detecting metal surface defects including a camera, and a method for detecting metal surface defects are provided for a surface of a metal object, such as a metal steel sheet moving at a stationary or relatively high speed.
  • An image of a same visual point may be obtained by minimizing the loss of light. Therefore, the present invention can obtain image information for a more sharp surface defect.
  • the present invention can acquire images of sharp surface defects, it is possible to improve the detection rate of the surface defects on the metal surface of the production product which is typically moving at high speed in the steel industry, and based on this, the quality control of the steel products is greatly improved. You can contribute.
  • the present invention moves at a higher speed or inspects surface defects of finer metals by acquiring images having two or four different positions and angles of light in one shot. To allow surface defect inspection of metals.
  • the present invention acquires the image of the simultaneous point, synchronization of the brightfield image and the darkfield image can be clearly performed. Since the present invention does not require an additional device such as an encoder for synchronizing positions of images, it is possible to reduce the complexity of the camera system, which is an optical system for surface defect detection, and to significantly reduce the configuration cost of the camera system.
  • the present invention when using a light having two different wavelength bands by distinguishing the horizontal polarization (horizontal wave) and the vertical polarization (longwave) for the wavelength band of each of the illumination by the position of the four different lights and The image according to the angle can be acquired at the same time.
  • the present invention can have an improved rate of detection of surface defects in metals.
  • FIG. 1 is a view showing a surface defect detection apparatus 50 of a metal object compared with the present invention.
  • FIG. 2 is a diagram illustrating a method of operating the light sources 20 and 30 shown in FIG. 1.
  • FIG. 3 is a diagram illustrating an apparatus 90 for detecting surface defects of a moving metal object compared to the present invention.
  • FIG. 5 is a diagram illustrating a camera 100 for detecting metal surface defects according to an embodiment of the present invention.
  • FIG. 6 is a view for explaining an embodiment of the polarization separator 115 shown in FIG.
  • FIG. 7 is a view for explaining the metal surface defect detection apparatus 200 according to an embodiment of the present invention.
  • FIG. 8 is a view for explaining a method of operating the light sources 205 and 210 shown in FIG. 7.
  • FIG. 9 is a view for explaining a metal surface defect detection apparatus 300 according to another embodiment of the present invention.
  • FIG. 10 is a plan view illustrating an embodiment of an illumination arrangement of the metal surface defect detection apparatus 300 shown in FIG. 9.
  • FIG. 11A is a view for explaining the relationship between the surface defect form of the metal object shown in FIG. 9 and the illumination arrangement shown in FIG. 10.
  • FIG. 11B is a view for explaining another relationship between the surface defect shape of the metal object shown in FIG. 9 and the illumination arrangement shown in FIG. 10.
  • a system for detecting the shape and location of metal surface defects may consist of one camera and two lights of different illumination angles and on the same plane.
  • the shape and location of surface defects are detected through two images obtained by sequentially blinking a bright field light and a dark field light.
  • metal sheets are moving at high speeds and the surface defects vary, so depending on the location and angle of illumination, surface defects may or may not be captured in the camera image.
  • the surface defect detection apparatus 50 includes a camera 10, a first light source 20, and a second light source 30.
  • the surface defect detection device 50 may be a multiview system.
  • the camera 10 is not a camera that distinguishes different wavelength bands, but is a single charge coupled device (CCD) camera. Therefore, the surface defect detection apparatus 50 constitutes the first light source 20 in the bright field condition and the second light source 30 in the dark field condition, and as shown in FIG. 2, the first light source 20 and the second light source. Acquiring an image by sequentially flashing the 30, and analyzing the acquired image through an image processing unit included in the surface defect detection device 50, to determine the surface of the stationary metal 40 as an object to be detected. Detect defects Therefore, when the method of the surface defect detection apparatus 50 is applied to a moving metal object, there is a problem in that the position difference of the image by the distance moved during the blinking time difference of the two lights 20 and 30 occurs.
  • CCD charge coupled device
  • the surface defect detection apparatus 90 of the metal object includes a first camera 60, a second camera 65, a first light source 70, and a second light source 75.
  • the first camera 60 or the second camera 65 is not a camera that distinguishes different wavelength bands, but is a single CCD camera. Thus, the two lights 70, 75 alternately irradiate the surface of the moving metal object 80 as shown in FIG. 2.
  • the surface defect detection apparatus 90 of the metal object shown in FIG. 3 is used.
  • the first camera 60 and the second camera 65 acquire images sequentially with respect to the moving direction of the metal object 80. That is, after the first camera 60 acquires the image by the illumination of the first light source 70 in the dark field condition, the second camera 65 is the illumination of the second light source 75 in the bright field condition. Acquire an image.
  • the surface defect detection apparatus 90 of the metal object may be a multiview system.
  • Encoder or speed meter for measuring the position change of the metal object 80 to synchronize the position of the image between the image acquired by the first camera 60 and the image obtained by the second camera 65.
  • An additional device such as) is required for the surface defect detection device 90 of the metal object.
  • the surface defect detection device 90 synchronizes the positions of the images and analyzes the images acquired by the first camera 60 and the second camera 65 through an image processing unit therein to detect surface defects of the metal object 80. Detect.
  • the camera 95 includes a lens 11, a prism (or beam splitter) 12, a first charge coupled device (CCD) 13, and a second CCD 14 is included.
  • Camera 95 may also be referred to as a two CCD type camera.
  • the first CCD 13 and the second CCD 14 may each have a color filter for passing only light of a specific wavelength band provided in front of the first CCD 13 and the second CCD 14.
  • the prism 12 divides two lights of different wavelength bands (50%), which are surface reflections of the metal object incident through the lens 11, into the first CCD 13 and the second CCD 14, respectively. Each incident.
  • the camera 95 may obtain the image of the simultaneous point by acquiring the light irradiated simultaneously to the surface of the metal object by two illuminations of different wavelength bands.
  • the light irradiated is not polarized illumination.
  • the camera 95 equally divides the amount of light incident on the prism 12 through the lens 11 (or the intensity of light) by using the prism 12 and evenly divides the light by half (50%).
  • the incident images of the same surface of the metal object can be obtained by injecting into 13 and the second CCD 14, respectively. Therefore, as the amount of light loss occurs as shown in FIG. 4, the camera 95 obtains an image at least 50% darker than the camera of FIG. 1 or 2 using a single CCD camera. Considering the filter installed in front of the first CCD 13 and the second CCD 14, the camera 95 acquires a darker image.
  • the illumination should be brighter or the amount of light loss in the camera 95 should be reduced.
  • the camera 100 includes a body 105, a lens 110, a polarization separator 115, a first charge coupled device (CCD) 120, and a second CCD 125. It includes.
  • the camera 100 obtains an image of a simultaneous point using the reflected light 130 which is irradiated on the surface of the metal object simultaneously with two illuminations (horizontal wave and longitudinal wave) that are linearly polarized to be orthogonal to each other in the same wavelength band.
  • the reflected light 130 is linearly polarized light that is incident to the camera 100 through the lens 110 and has the same wavelength band and is orthogonal to each other and is free from interference.
  • the camera 100 includes two CCDs 120 and 125 each having the same viewing angle, and each of the CCDs 120 and 125 has a vertical polarization 135 according to the vibration direction of light in the surface reflection image.
  • Image and horizontal polarization 140 are obtained.
  • An image of horizontally polarized wave or horizontally polarized light and an image of vertically polarized wave or vertically polarized light are independent images. Therefore, the camera 100 may obtain two simultaneous point image information.
  • the polarization separator 115 passes the vertical polarization 135 of the reflected light 130 toward the first CCD 120 and reflects the horizontal polarization 140 of the reflected light 130 toward the second CCD 125 so that the camera 100 may be reflected.
  • Vertical polarization (longwave) and horizontal polarization (horizontal wave) incident on the surface are separated with little loss of light amount. Therefore, the polarization separator 115 may suppress the loss of the amount of light generated by the prism 12 shown in FIG. 4.
  • FIG. 6 is a view for explaining an embodiment of the polarization separator 115 shown in FIG.
  • the polarization separator 115 may be implemented as a cube-shaped polarizing beamsplitter cube.
  • the polarizing beam splitter cube If the light incident on the polarizing beam splitter cube is linearly polarized light, the light is separated into components perpendicular to each other according to the direction of the linearly polarized light. Therefore, when the light incident on the polarization beam splitter cube is linearly polarized light orthogonal to each other, when the direction of the polarization beam splitter cube is adjusted, the polarization beam splitter cube is vertically polarized (135) among the reflected light 130 incident on the polarization beam splitter cube. ) Passes through and reflects the horizontal polarization 140 of the reflected light 130. As a result, the camera 100 can obtain independent images with little loss of light and no interference with each other.
  • the polarizing beamsplitter cube includes two rectangular prisms.
  • a dielectric coating layer 116 is disposed (formed) between the right prisms.
  • the vertical polarization 135 may be generated by transmitting the reflected light 130 from the dielectric coating layer 140, and the horizontal polarization 140 may be generated by reflecting the reflected light 130 from the dielectric coating layer 140.
  • the first CCD 120 and the second CCD 125 each constitute an imaging device as a sensor.
  • the first CCD 120 acquires an image (image information) of the vertical polarization 135 separated by the polarization separator 115, and the second CCD 125 obtains an image of the horizontal polarization 140. That is, the first CCD 120 converts the optical signal of the vertical polarization 135 into an electrical signal, and the second CCD 125 converts the optical signal of the horizontal polarization 140 into an electrical signal.
  • Each of the first CCD 120 and the second CCD 125 may include a color filter array and a photodiode.
  • the camera 100 of the present invention includes a polarization separator 115, there is almost no loss of light compared to the camera 95 of FIG. 4 which acquires an image by two illuminations having different wavelength bands. Since illumination of the same wavelength band can be used to obtain a very bright image for detecting a surface defect of a metal object, surface defects of a metal object moving at high speed can be effectively detected.
  • the metal surface defect detecting apparatus 200 may include a camera 100, a first light source 205, and a second light source 210.
  • the camera 100 includes the components of the camera 100 shown in FIG. 5.
  • Each of the first light source 205 and the second light source 210 may include a light emitted diode.
  • a xenon lamp or a halogen lamp may be used instead of the light emitting diode (LED).
  • the first light source 205 or the second light source 210 may include an optical filter. The optical filter may be installed on the front surface of the first light source 205 or on the front surface of the second light source 210.
  • the first light source 205 is illumination in a bright field condition and linearly polarized light
  • the second light source 210 is illumination in a dark field condition and linearly polarized light.
  • the bright field condition illumination and the dark field condition illumination are linearly polarized lights having the same wavelength band and orthogonal to each other.
  • the first light source 205 irradiates the surface of the metal object 215 with linearly polarized light under bright field conditions.
  • the first light source 205 may be brightfield illumination and should be disposed at an angle as close to 90 degrees as possible from the surface of the metal object 215 and at an angle of approximately 80 degrees in consideration of the installation of the illumination. May be
  • the second light source 210 irradiates the surface of the metal object 215 simultaneously with the first light source 205 with linearly polarized light that is orthogonal to the illumination of the first light source 205 in the dark field condition.
  • the second light source 210 may be dark field illumination and may be disposed at an angle that is greater than 0 degrees and less than 45 degrees from the surface of the metal object 215, for example. The angle of the dark field illumination is effective to be adjusted according to the defect characteristics of the metal object.
  • Bright field illumination indicates illumination with a relatively high angle of illumination (light source).
  • brightfield illumination is illuminating the light from a metal surface at a high angle so that shadows of metal surface defects do not occur.
  • Dark field illumination indicates illumination with relatively low angles of illumination.
  • dark field illumination is illumination from a low angle from the metal surface so that the shadow of the metal surface defect is generated as much as possible.
  • the first light source 205 and the second light source 210 may be opposite to each other with respect to a vertical line from which the camera 100 acquires a surface reflection image of the metal object 215. Can be arranged. That is, when viewed from above the camera 100, the camera 100 may be disposed between the first light source 205 and the second light source 210.
  • FIG. 8 is a view for explaining a method of operating the light sources 205 and 210 shown in FIG. 7. As shown in FIG. 8, the first light source 205 and the second light source 210 may be turned on at the same time and turned off at the same time.
  • the camera 100 simultaneously acquires a brightfield image and a darkfield image at the same point on the surface of the metal object 215.
  • the camera 100 acquires light (or lights) that are simultaneously irradiated by the first light source 205 and the second light source 210 and reflected from the surface of the metal object 215 to inspect the surface defects of the metal object 215. Acquire an image for.
  • the metal object 215 may be a stationary metal object (eg, a metal sheet) or a moving metal object.
  • the metal surface defect detecting apparatus 200 obtains two independent images at the same time by irradiating two independent lights 205 and 210 of the same wavelength band to the surface of the metal object 215. Each of the lights 205, 210 includes two linearly polarized lights that are orthogonal to each other.
  • the image signal processing apparatus included in the metal surface defect detecting apparatus 200 receives the image information (image signal) acquired by the camera 100, analyzes the signal, and processes the surface of the metal object 215. Detect the type and location of the defect.
  • the image signal processing apparatus may be connected to a screen output device (not shown) included in the metal surface defect detecting apparatus 200.
  • the screen output apparatus may output a screen of an image processed by the image signal processing apparatus.
  • the image signal processing apparatus may be implemented by hardware, software, or a combination thereof, and may be implemented by a dedicated processor or a computer.
  • the metal surface defect detecting apparatus 200 has two different illumination positions and angles in one shot, compared to the image processing method obtained by the sequential blinking method of illumination illustrated in FIG. 1 or 3. By acquiring, it is possible to inspect the surface defects of a more detailed metal object or to inspect the surface defects of a metal object moving at high speed.
  • the metal surface defect detection apparatus 200 of the present invention acquires images of the simultaneous point, the bright field image and the dark field image may be clearly synchronized.
  • the present invention does not require an additional device such as an encoder for synchronizing positions of images, thereby reducing the complexity of the camera system, which is an optical system for surface defect detection. The construction cost of the camera system can be significantly reduced.
  • a metal surface defect detection method is described as follows.
  • the metal surface defect detection method may be applied to the metal surface defect detection apparatus 200 shown in FIG. 7.
  • the metal surface defect detection method includes a first irradiation step, a second irradiation step, an acquisition step, and a detection step.
  • the linearly polarized light in the bright field condition is irradiated onto the surface of the metal object 215 by the first light source 205.
  • the metal object 215 may be a stationary metal object or a moving metal object.
  • the linearly polarized light having a wavelength perpendicular to the illumination of the first light source 205 and having the same wavelength as that of the illumination of the first light source 205 in the dark field condition is generated by the second light source 210.
  • the surface of the metal object 215 is irradiated at the same time as the bright field illumination by the first light source 205.
  • the image of the light reflected from the surface of the metal object 215 is acquired by the camera 100 at the same time.
  • the camera 100 may include a polarizing beamsplitter cube.
  • the image signal processing apparatus of the metal surface defect detecting apparatus 200 performs signal processing (for example, digital image signal processing) on the obtained image to detect a surface defect (surface defect image) of the metal object 215. Is detected.
  • signal processing for example, digital image signal processing
  • the metal surface defect detecting apparatus 300 may include a camera unit 305, a first light source 325, a second light source 330, a third light source 335, and a fourth light source.
  • Light source 340 may include a camera unit 305, a first light source 325, a second light source 330, a third light source 335, and a fourth light source.
  • Each of the first light source 325, the second light source 330, the third light source 335, and the fourth light source 340 may include a light emitting diode, a xenon lamp, or a halogen lamp.
  • the first light source 325, the second light source 330, the third light source 335, or the fourth light source 340 may include an optical filter.
  • the optical filter may be installed on the front surface of the first light source 325, the front surface of the second light source 330, the front surface of the third light source 335, or the front surface of the fourth light source 340.
  • the center wavelength band of the first light source 325 and the center wavelength band of the fourth light source 340 are the same as the first wavelength ⁇ 1, and the first light source 325 and the fourth light source 340 are Linearly polarized lights that are orthogonal to one another.
  • the center wavelength band of the second light source 330 and the center wavelength band of the third light source 335 are the same as the second wavelength ⁇ 2, and the second light source 330 and the third light source 335 are perpendicular to each other. Linearly polarized lights.
  • the first light source 325 irradiates the surface of the metal object 345 with linearly polarized light having a first wavelength ⁇ 1 at a first angle
  • the second light source 330 has a second wavelength ⁇ 2 at a second angle.
  • Linearly polarized light of the metal object 345 is irradiated to the surface of the metal object 345
  • the third light source 335 is irradiated to the surface of the metal object 345 of the linearly polarized light of the second wavelength ( ⁇ 2) at a third angle
  • the light source 340 irradiates the surface of the metal object 345 with linearly polarized light having a first wavelength ⁇ 1 at a fourth angle.
  • the first angle may be an angle for brightfield illumination
  • the second angle, the third angle, and the fourth angle may be an angle for darkfield illumination
  • the brightfield illumination should be placed at an angle as close to 90 degrees as possible from the surface of the metal object 345 and may be arranged at an angle of approximately 80 degrees in consideration of the position of the illumination.
  • the dark field illumination may be disposed at an angle that is greater than 0 degrees and less than 45 degrees from the surface of the metal object 345 according to the defect characteristics of the metal object.
  • the first light source 325, the second light source 330, the third light source 335, and the fourth light source 340 emit the polarizations (lights) in a manner similar to that shown in FIG. 8. Irradiate simultaneously on the surface.
  • the camera unit 305 includes a first camera 310, a second camera 315, and a dichroic mirror or dichroic beamsplitter 320.
  • the camera unit 305 is irradiated simultaneously by the first light source 325, the second light source 330, the third light source 335, and the fourth light source 340 and reflected from the surface of the metal object 345 ( By acquiring light), an image for inspecting a surface defect of the metal object 345 is obtained.
  • the color screening mirror 320 separates the light reflected from the surface of the metal object 345 into light having a first wavelength ⁇ 1 and light having a second wavelength ⁇ 2.
  • the dichroic mirror 320 transmits light in the wavelength band of ⁇ 1 and reflects light in the wavelength band of ⁇ 2 with little loss of light due to the interference effect of light in the multilayer thin film therein. Therefore, the first camera 310 and the second camera 315 can obtain a high-definition video image with little loss of light.
  • the first camera 310 obtains the light having the first wavelength ⁇ 1 separated by the color-dividing mirror 320 into vertical and horizontal polarizations, and uses the obtained vertical and horizontal polarizations to detect the metal object 345. Image for surface defect inspection).
  • the second camera 315 is obtained by dividing the light of the second wavelength ⁇ 2 separated from the color-dividing mirror 320 into vertical and horizontal polarizations, and using the obtained vertical and horizontal polarizations, the metal object 345. Image for surface defect inspection).
  • the first camera 310 or the second camera 315 includes the components of the camera 100 shown in FIG. 5.
  • the metal object 345 may be a stationary metal object (eg, a metal sheet) or a moving metal object.
  • the metal surface defect detecting apparatus 300 may simultaneously irradiate the surface of the metal object 345 with four independent polarization lights 325, 330, 335, and 340 of two different wavelength bands ⁇ 1 and ⁇ 2. Acquire four independent images of time at the same time.
  • the image signal processing apparatus included in the metal surface defect detecting apparatus 300 receives the image information acquired by the camera unit 305, analyzes the signal, and processes the signal to form a surface defect of the metal object 345. Detect and position.
  • the image signal processing apparatus may be connected to a screen output device (not shown) included in the metal surface defect detecting apparatus 300.
  • the screen output apparatus may output a screen of an image processed by the image signal processing apparatus.
  • the image signal processing apparatus may be implemented by hardware, software, or a combination thereof, and may be implemented by a dedicated processor or a computer.
  • the metal surface defect detecting apparatus 300 has an image having positions and angles of four different illuminations in one shot as compared to the image processing method obtained by the sequential blinking method of illumination illustrated in FIG. 1 or 3. By acquiring, it is possible to inspect the surface defects of a more detailed metal object or to inspect the surface defects of a metal object moving at high speed.
  • the metal surface defect detecting apparatus 300 of the present invention acquires an image of a simultaneous point, the bright field image and the dark field image may be clearly synchronized.
  • the present invention does not require an additional device such as an encoder for synchronizing positions of images, thereby reducing the complexity of the camera system, which is an optical system for surface defect detection. The construction cost of the camera system can be significantly reduced.
  • the metal surface defect detection apparatus 300 of the present invention uses four different illuminations by distinguishing horizontal polarization and vertical polarization for illuminations of the same wavelength band when the illumination having two different wavelengths is used. Images according to the position and angle of can be acquired simultaneously. Accordingly, the present invention may have an improved metal surface defect detection rate than the surface defect detection device 90 shown in FIG. 3.
  • FIG. 10 is a plan view illustrating an embodiment of an illumination arrangement of the metal surface defect detection apparatus 300 shown in FIG. 9.
  • the first light sources ⁇ 1 and 325 and the fourth light sources ⁇ 1 and 340 are disposed to face each other with respect to the camera unit 305 (or to the center), and the second light sources ⁇ 2 and 330. ) And the third light sources ⁇ 2 and 335 are disposed to face each other with respect to the camera unit 305.
  • the first light source ⁇ 1 and the fourth light source ⁇ 1, which are the first illumination pair, are disposed to be perpendicular to the second light source ⁇ 2 and the third light source ⁇ 2, which are the second illumination pair.
  • the camera unit 305 when viewed from above the camera unit 305, the camera unit 305 is disposed between the first light source ⁇ 1 and the fourth light source ⁇ 1, and between the second light source ⁇ 2 and the third light source ⁇ 2.
  • the first light source ⁇ 1 and the fourth light source ⁇ 1 are arranged perpendicularly (orthogonally) with respect to the second light source ⁇ 2 and the third light source ⁇ 2.
  • FIG. 11A is a view for explaining the relationship between the surface defect form of the metal object shown in FIG. 9 and the illumination arrangement shown in FIG. 10.
  • the defect DEFECT of the metal object is narrow in the direction of the first light source ⁇ 1 and the direction of the fourth light source, the defect is caused by the first light source ⁇ 1 and the fourth light source ⁇ 1.
  • the detection probability of DEFECT is low
  • the width of the defect DEFECT of the metal object is wide in the direction of the second light source ⁇ 2 and the direction of the third light source ⁇ 2, so that the second light source ⁇ 2 and the third light source are By ( ⁇ 2), the probability of detecting a defect is high.
  • FIG. 11B is a view for explaining another relationship between the surface defect shape of the metal object shown in FIG. 9 and the illumination arrangement shown in FIG. 10.
  • the second light source ⁇ 2 and the third light source ⁇ 2 may be formed.
  • the detection probability of the defect DEFECT is low
  • the width of the defect DEFECT of the metal object is wide in the direction of the first light source ⁇ 1 and the direction of the fourth light source ⁇ 1.
  • the fourth light source ⁇ 1 has a high probability of detecting a defect DEFECT.
  • the embodiment of the illumination arrangement shown in FIG. 10 can improve the probability of detecting a defect regardless of the shape of the defect or the direction of the defect.
  • a metal surface defect detection method is described as follows.
  • the metal surface defect detection method may be applied to the metal surface defect detection apparatus 300 shown in FIG. 9.
  • the metal surface defect detection method includes a first irradiation step, a second irradiation step, a third irradiation step, a fourth irradiation step, an acquisition step, and a detection step.
  • a first irradiation step linearly polarized light having a first wavelength ⁇ 1 at a first angle is irradiated onto the surface of the metal object 345 by the first light source 325.
  • the metal object 345 may be a stationary metal object or a moving metal object.
  • the first angle may be an angle for brightfield illumination or darkfield illumination.
  • the linearly polarized light of the second wavelength ⁇ 2 at the second angle is irradiated onto the surface of the metal object 345 by the second light source 330.
  • the second angle may be an angle for brightfield illumination or darkfield illumination.
  • the third angle may be an angle for brightfield illumination or darkfield illumination.
  • the linearly polarized light of the first wavelength ⁇ 1 orthogonal to the linearly polarized light of the first wavelength ⁇ 1 at a fourth angle is transferred to the metal object 345 by the fourth light source 340. Irradiated to the surface.
  • the fourth angle may be an angle for brightfield illumination or darkfield illumination.
  • the illumination of the first wavelength and the illumination of the second wavelength are simultaneously irradiated in a manner similar to that shown in FIG. 8.
  • the illumination of the first to fourth irradiation steps is irradiated so that an image of light reflected from the surface of the metal object 345 is simultaneously acquired by the camera unit 305.
  • the camera unit 305 includes a first camera 310, a second camera 315, and a color screening mirror 320.
  • the image signal processing apparatus of the surface defect detection apparatus 300 performs signal processing (for example, digital image signal processing) on the obtained image to detect surface defects (surface defect images) of the metal object 345. Detect.
  • signal processing for example, digital image signal processing

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

Abstract

L'invention concerne une caméra pour détecter un défaut d'une surface métallique, ladite caméra comprenant: un séparateur polarisant; un premier dispositif à transfert de charge; et un deuxième dispositif à transfert de charge. Quand le séparateur polarisant émet simultanément sur une surface d'un objet métallique des lumières polarisées linéairement qui se coupent mutuellement, la lumière réfléchie par la surface de l'objet métallique est séparée en lumière polarisée verticalement et en lumière polarisée horizontalement. Le premier dispositif à transfert de charge (CCD) acquiert une image polarisée verticalement. Le deuxième dispositif à transfert de charge acquiert une image polarisée horizontalement.
PCT/KR2011/005282 2011-07-18 2011-07-19 Caméra pour détecter des défauts d'une surface métallique, dispositif incluant la caméra pour détecter des défauts d'une surface métallique et procédé pour détecter des défauts d'une surface métallique Ceased WO2013012106A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1020110070941A KR101078404B1 (ko) 2011-07-18 2011-07-18 금속 표면 결함 검출을 위한 카메라．카메라를 포함하는 금속 표면 결함 검출 장치，및 금속 표면 결함 검출 방법
KR10-2011-0070941 2011-07-18

Publications (1)

Publication Number Publication Date
WO2013012106A1 true WO2013012106A1 (fr) 2013-01-24

Family

ID=45396943

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2011/005282 Ceased WO2013012106A1 (fr) 2011-07-18 2011-07-19 Caméra pour détecter des défauts d'une surface métallique, dispositif incluant la caméra pour détecter des défauts d'une surface métallique et procédé pour détecter des défauts d'une surface métallique

Country Status (2)

Country Link
KR (1) KR101078404B1 (fr)
WO (1) WO2013012106A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107770417A (zh) * 2016-08-18 2018-03-06 韩华泰科株式会社 部件贴装机的相机模块
CN114544671A (zh) * 2020-11-26 2022-05-27 西北工业大学深圳研究院 一种基于双波段偏振成像的pcb板缺陷图像采集装置
WO2023166898A1 (fr) * 2022-03-03 2023-09-07 Ｊｆｅスチール株式会社 Procédé d'inspection de surface pour matériau métallique, appareil d'inspection de surface pour matériau métallique et matériau métallique
US12305973B2 (en) 2022-02-09 2025-05-20 Caterpillar Inc. Automated seal inspection system

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103743758A (zh) * 2014-01-15 2014-04-23 唐山英莱科技有限公司 一种基于正交偏振的高反光金属表面视觉检测系统
KR101876628B1 (ko) * 2016-09-08 2018-08-02 주식회사 맥사이언스 야외 태양전지모듈 위상잠금 발광 화상 검사 장치 및 방법
KR101791469B1 (ko) 2016-10-14 2017-10-30 주식회사 윈텍오토메이션 제품의 대칭성과 영상 유사도를 이용한 초경인서트 결함 검출방법
IT201800005962A1 (it) * 2018-06-01 2019-12-01 Sistema ottico per l'identificazione di difetti
KR102848747B1 (ko) * 2023-11-01 2025-08-22 (주)넥스틴 조명 장치 및 이를 포함하는 반도체 검사 장치

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0792104A (ja) * 1993-09-27 1995-04-07 Mec:Kk 被検査物の不良個所検査方法
KR0125596B1 (ko) * 1993-12-14 1998-07-01 안시환 표면결함 검사방법 및 그 장치
KR20010067345A (ko) * 1999-10-26 2001-07-12 가나이 쓰토무 비파괴 검사 방법 및 그 장치
KR20100058012A (ko) * 2008-11-24 2010-06-03 참앤씨(주) 불량 검사를 위한 광학 시스템

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0792104A (ja) * 1993-09-27 1995-04-07 Mec:Kk 被検査物の不良個所検査方法
KR0125596B1 (ko) * 1993-12-14 1998-07-01 안시환 표면결함 검사방법 및 그 장치
KR20010067345A (ko) * 1999-10-26 2001-07-12 가나이 쓰토무 비파괴 검사 방법 및 그 장치
KR20100058012A (ko) * 2008-11-24 2010-06-03 참앤씨(주) 불량 검사를 위한 광학 시스템

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107770417A (zh) * 2016-08-18 2018-03-06 韩华泰科株式会社 部件贴装机的相机模块
CN107770417B (zh) * 2016-08-18 2020-12-18 韩华精密机械株式会社 部件贴装机的相机模块
CN114544671A (zh) * 2020-11-26 2022-05-27 西北工业大学深圳研究院 一种基于双波段偏振成像的pcb板缺陷图像采集装置
US12305973B2 (en) 2022-02-09 2025-05-20 Caterpillar Inc. Automated seal inspection system
WO2023166898A1 (fr) * 2022-03-03 2023-09-07 Ｊｆｅスチール株式会社 Procédé d'inspection de surface pour matériau métallique, appareil d'inspection de surface pour matériau métallique et matériau métallique
JPWO2023166898A1 (fr) * 2022-03-03 2023-09-07
JP7741179B2 (ja) 2022-03-03 2025-09-17 Ｊｆｅスチール株式会社 鋼材の表面検査方法及び表面検査装置

Also Published As

Publication number Publication date
KR101078404B1 (ko) 2011-11-01

Similar Documents

Publication Publication Date Title
WO2013012106A1 (fr) Caméra pour détecter des défauts d'une surface métallique, dispositif incluant la caméra pour détecter des défauts d'une surface métallique et procédé pour détecter des défauts d'une surface métallique
US6346966B1 (en) Image acquisition system for machine vision applications
WO2015080480A1 (fr) Appareil d'inspection d'image de tranche de semi-conducteur
KR101972517B1 (ko) 검사대상체 표면 검사를 위한 듀얼 라인 광학 검사 시스템
WO2013048093A2 (fr) Appareil et procédé d'inspection de composant sans contact
CN105358966A (zh) 用于对长材进行表面检查的方法以及适用于执行这样的方法的设备
WO2011087337A2 (fr) Dispositif d'inspection de substrat
WO2014163375A1 (fr) Procédé de recherche d'une substance étrangère sur un substrat
WO2001049043A1 (fr) PROCEDE PERMETTANT D'APPLIQUER SIMULTANEMENT PLUSIEURS TYPES D'ECLAIRAGE EN VUE DE L'ACQUISITION D'IMAGES SIMULTANEE DANS UN SYSTEME D'IMAGERIE
WO2016200096A1 (fr) Appareil de mesure de forme tridimensionnelle
WO2012023816A9 (fr) Microscope à fluorescence pour observation d'image à fluorescence multiple, procédé d'observation d'image à fluorescence l'utilisant, et système d'observation d'image à fluorescence multiple
WO2017204560A1 (fr) Procédé et appareil de détection de particules sur une surface supérieure de verre, et procédé d'exposition à un rayonnement de lumière incidente
WO2013176482A1 (fr) Procédé de mesure de la hauteur pour un dispositif de mesure de formes tridimensionnelles
WO2019031667A1 (fr) Dispositif et procédé de mesure de l'épaisseur et de l'indice de réfraction d'un film mince multicouche par réflectométrie spectrale à résolution angulaire
WO2023008709A1 (fr) Appareil d'irradiation de lumière multi-spectre et système d'imagerie par fluorescence multi-spectre
US20090073426A1 (en) Multiple Surface Inspection System and Method
WO2015167104A1 (fr) Appareil et procede de detection d'un materiau etranger sur la surface superieure d'un substrat transparent a l'aide de lumiere polarisee
TW561240B (en) Illumination system used for apparatus for inspecting surface-mounted chip
WO2011083989A2 (fr) Dispositif de contrôle de défaut
WO2017200226A1 (fr) Dispositif de mesure de forme tridimensionnelle au moyen d'un interféromètre à balayage optique multi-longueurs d'onde
WO2012020932A2 (fr) Dispositif d'inspection de défauts et procédé d'inspection de défauts l'utilisant
WO2009119983A2 (fr) Système de vérification d'un substrat fpd et de tranches à semi-conducteurs utilisant des images dupliquées
EP1978353B1 (fr) Système et procédé d'inspection de surfaces multiples
JP2002214158A (ja) 透明板状体の欠点検出方法および検出装置
WO2014192999A1 (fr) Système d'inspection d'un défaut pour inspecter un objet ayant des structures irrégulières

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11869576

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11869576

Country of ref document: EP

Kind code of ref document: A1