WO2013077282A1 - Inspection method for liquid-crystal display panel - Google Patents

Inspection method for liquid-crystal display panel Download PDF

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Publication number
WO2013077282A1
WO2013077282A1 PCT/JP2012/079914 JP2012079914W WO2013077282A1 WO 2013077282 A1 WO2013077282 A1 WO 2013077282A1 JP 2012079914 W JP2012079914 W JP 2012079914W WO 2013077282 A1 WO2013077282 A1 WO 2013077282A1
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WIPO (PCT)
Prior art keywords
liquid crystal
crystal display
display panel
substrate
camera
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PCT/JP2012/079914
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French (fr)
Japanese (ja)
Inventor
吉弘 西村
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シャープ株式会社
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Publication of WO2013077282A1 publication Critical patent/WO2013077282A1/en

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    • 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
    • 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
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/94—Investigating contamination, e.g. dust
    • 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
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • 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
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N2021/9513—Liquid crystal panels

Definitions

  • the present invention relates to an inspection method for a liquid crystal display panel, and more particularly to an inspection method for inspecting the presence or absence of a defect in a liquid crystal panel. Note that this application claims priority based on Japanese Patent Application No. 2011-256976 filed on November 25, 2011, the entire contents of which are incorporated herein by reference. .
  • the inspection process for the presence or absence of display defects on the display panel is generally performed by an inspector.
  • the visual inspection process by the inspector is performed using a limit sample which is a sample of the lowest quality that can be handled as a non-defective product. More specifically, the pass / fail (presence / absence of display defect) is determined by the inspector comparing the liquid crystal display panel and the limit sample.
  • a method has been proposed in which a liquid crystal display panel is illuminated with a backlight, and defects in the liquid crystal display panel are imaged with an imaging device (for example, a CCD camera) to inspect the presence or absence of display defects in the liquid crystal display panel.
  • an imaging device for example, a CCD camera
  • FIG. 10 shows a configuration of a conventional liquid crystal display panel inspection apparatus 1000.
  • this automatic inspection apparatus 1000 the presence or absence of defects in the liquid crystal display panel 101 can be automatically inspected (for example, Patent Literature 1). 1).
  • the foreign object detection unit 200 irradiates the front and back surfaces 101 a and 101 b of the liquid crystal display panel 101 with the irradiation light 290 from the irradiation lamp 400 while transporting the liquid crystal display panel 101.
  • the first image data on the front and back surfaces 101a and 101b of the liquid crystal display panel 101 is captured by the line sensor 500 that receives the reflected lights 320 and 330.
  • the positions of bright spots on the front and back surfaces 101a and 101b of the liquid crystal display panel 101 are acquired via the image processing device 150.
  • the image processing device 150 includes an A / D converter 160, a position data calculation unit 170, a storage unit 180, and a defect detection unit 190.
  • the display defect detection unit 300 irradiates the liquid crystal display panel 101 mounted on the inspection table 120 with the irradiation light 390 from the backlight 110.
  • the camera 140 captures the second image data of the inside of the liquid crystal display panel 101 and the front and back surfaces 101a and 101b.
  • the positions of bright spots in the liquid crystal display panel 101 and on the front and back surfaces 101a and 101b are acquired via the image processing device 150 based on the captured second image data.
  • the bright spot based on the defect 340 inside the liquid crystal display panel 101 and the front and back surfaces of the liquid crystal display panel 101 are compared.
  • a bright spot based on the foreign matters 300 and 310 is distinguished. Thereby, it is possible to detect whether or not there is a defect inside the liquid crystal display panel 101.
  • the liquid crystal display panel 101 is conveyed and the liquid crystal display panel 101 is irradiated with light irradiated by the irradiation lamp 400 on the front and back surfaces of the liquid crystal display panel. It is necessary to capture image data of the front and back surfaces 101a and 101b of the display panel 101. For this reason, there is a problem that the structure of the inspection apparatus 1000 used for the inspection of the liquid crystal display panel 101 is complicated and the process for performing the inspection is complicated. Further, this inspection process has a problem that it takes a long time to inspect the liquid crystal display panel 101.
  • the present invention has been made in view of the above points, and its main purpose is to simplify a process for inspecting a liquid crystal display panel and to shorten a time required for inspecting the liquid crystal display panel. It is to provide a panel inspection method.
  • An inspection method includes a first substrate, a second substrate disposed to face the first substrate, and a liquid crystal layer provided between the first substrate and the second substrate.
  • the first image data of the liquid crystal display panel is captured by a camera so as to focus on any of the first substrate, the liquid crystal layer, and the second substrate in the liquid crystal panel, Based on the first image data, a first contrast value at a position corresponding to a foreign substance that may exist on the front surface of the first substrate and the back surface of the second substrate, and a position corresponding to a defect inside the liquid crystal panel
  • a first contrast value at a position corresponding to a foreign substance that may exist on the front surface of the first substrate and the back surface of the second substrate, and a position corresponding to a defect inside the liquid crystal panel
  • taking the second image data of the liquid crystal display panel with the camera so as to focus on the foreign matter that may be present on the surface of the first substrate, and based on the second image data , A position
  • the focusing from the step (a) to the step (c) is performed by adjusting a drawing amount of the lens of the camera.
  • the camera is a single camera, and in the step (a), the focus is adjusted based on the surface of the first substrate.
  • the cameras are three cameras, and the first to third image data in the steps (a) to (c) are the same step by the three cameras having different focus. The image is taken.
  • each of the first to third contrast values uses an integral value of a contrast at a position corresponding to the foreign matter and the defect in the first to third image data as an index.
  • the first contrast value is most determined by comparing the first to third contrast values at a first position where any of the foreign matter and the defect exists. If larger, it is determined that the defect exists at the first position.
  • the second contrast value is the highest by comparing the first to third contrast values at the second position where either the foreign matter or the defect exists. If larger, it is determined that the foreign matter is present at the second position, and the first to third contrast values at the third position where either the foreign matter or the defect exists are compared, thereby When the 3 contrast value is the largest, it is determined that the foreign matter is present at the third position.
  • the relative value from the peak of the first to third contrast values is used to distinguish the foreign matter from the defect.
  • the camera is a CCD camera or a CMOS camera
  • the foreign matter is selected from the group consisting of a scraping scrap of a transport roller, a scraping scrap of a cleaning brush, and a scrap of a glass of a cutting machine. At least one.
  • Another inspection method includes a first substrate, a second substrate disposed opposite to the first substrate, a liquid crystal layer provided between the first substrate and the second substrate,
  • a liquid crystal display panel inspection method comprising: First image data of the liquid crystal display panel is picked up by a camera so as to focus on any of the first substrate, the liquid crystal layer, and the second substrate in the liquid crystal panel, and based on the first image data Obtaining a first contrast value at a position corresponding to a foreign substance that may be present on the surface of the first substrate and a position corresponding to a defect inside the liquid crystal panel; and may be present on the surface of the first substrate.
  • the second image data of the liquid crystal display panel is imaged by the camera so as to focus on the foreign matter, and the position corresponding to the foreign matter that may be present on the surface of the first substrate based on the second image data, and
  • the step of obtaining a second contrast value at a position corresponding to a defect inside the liquid crystal panel is compared with the first and second contrast values. , Comprising the step distinguishes the said and the foreign substance defect.
  • the first to third image data in the liquid crystal display panel is picked up by changing the focus of the camera, the first to third contrast values are obtained from the image data, and the first to third image data are obtained.
  • the third contrast value it is possible to distinguish foreign matters located on the front and back surfaces of the liquid crystal display panel from defects inside the liquid crystal display panel.
  • the process for inspecting the liquid crystal display panel can be simplified, and the time required for inspecting the liquid crystal display panel can be shortened.
  • FIG. 1 is a figure which shows the structure of the test
  • (b) is for demonstrating the example of the image data imaged with the camera 30 of the test
  • FIG. It is sectional drawing which shows the structure of the liquid crystal display panel 10 test
  • (A) to (c) is a conceptual diagram for explaining an inspection method according to the first embodiment of the present invention.
  • (A) And (b) is the table
  • (A) And (b) is the table
  • (A) to (c) is a conceptual diagram for explaining an inspection method for a liquid crystal display panel according to a second embodiment of the present invention. It is a conceptual diagram which shows the structure of the automatic test
  • FIG. 1B is a conceptual diagram illustrating an example of image data 40 captured by the lens 30 a of the camera 30.
  • FIG. 2 is a cross-sectional view for explaining the configuration of the liquid crystal display panel 10 inspected by the inspection apparatus 100 of the present embodiment.
  • An inspection apparatus (automatic inspection apparatus) 100 is an apparatus that distinguishes foreign matters 21 and 22 such as dust or dust on the front and back surfaces of the liquid crystal display panel 10 from defects 20 existing inside the liquid crystal display panel 10. is there.
  • the camera 30 is used to image the liquid crystal display panel 10 while adjusting the extension amount of the lens 30a, and the surface of the liquid crystal display panel 10 is displayed based on the captured image data 40. In this configuration, foreign substances 21 and 22 on the back surface and defects (or micro defects) 20 existing inside the liquid crystal display panel 10 are distinguished.
  • the image data 40 obtained by imaging the liquid crystal display panel 10 by the camera 30 includes a position 21P (first position) and a position 22P (second position) corresponding to the foreign matter 21, 22 or the defect 20. Position) or a point at position 20P (third position) is displayed. In this example, at these positions (21P, 22P, 20P), bright spots brighter than other regions are displayed due to the presence of the foreign matter 21, 22 or the defect 20.
  • the foreign substances 21 and 22 which are dust or dirt on the front and back surfaces of the liquid crystal display panel 10 include, for example, a scraped scrap of a transport roller, a scraped scrap of a cleaning brush, a scrap of a glass of a cutting machine, and the like.
  • the defects 20 inside the liquid crystal display panel 10 for example, foreign matter in the panel (insulator powder, metal powder, etc.) or alignment film defects (for example, locations where polyimide is not applied, so-called PI repellency) Is mentioned.
  • the liquid crystal display panel 10 inspected by the inspection apparatus 100 of the present embodiment is opposed to the color filter substrate (first substrate) 11 disposed on the camera 30 side and the color filter substrate 11. And the array substrate 12 arranged in this manner.
  • a switching element for example, a thin film transistor (TFT)
  • TFT thin film transistor
  • the color filter substrate 11 is provided with red (R), green (G), and blue (B) colored layers corresponding to each pixel, and the color filter substrate 11 may be referred to as a CF substrate.
  • the color filter substrate 11 of four primary colors (red (R), green (G), blue (B), and yellow (Y)) can be used.
  • the colored layer is not present on the first substrate 11, but the inspection method of the present embodiment can be applied even in that case.
  • a liquid crystal layer 15 as a display medium layer is provided between the CF substrate (first substrate) 11 and the TFT substrate (second substrate) 12.
  • the liquid crystal layer is made of a liquid crystal material whose optical characteristics change with application of an electric field between the CF substrate 11 and the TFT substrate 12.
  • the liquid crystal display panel 10 of the present embodiment generally has a rectangular shape as a whole, and the CF substrate (first substrate) 11 and the TFT substrate (second substrate) 12 are each a translucent substrate (glass). Substrate).
  • the liquid crystal display panel 10 is formed with a sealing material 14 provided on the frame for adhering the CF substrate 11 and the TFT substrate 12 to each other and enclosing the liquid crystal layer 15.
  • the sealing material 14 is formed so as to go around the liquid crystal layer 15, and the CF substrate 11 and the TFT substrate 12 are bonded to each other via the sealing material 14.
  • the CF substrate 11 is disposed on the display surface side (in this example, the upper side or the camera 30 side).
  • the camera 30 of the present embodiment is a CCD camera and is composed of a plurality of CCDs (charge-coupled devices).
  • CCD camera charge-coupled devices
  • the camera 30 is not limited to a CCD camera, and other cameras (for example, a CMOS camera) can be used.
  • the camera 30 is provided with a lens 30a that can change the feed amount, and the distance of the focus (focal point) can be changed by the lens 30a.
  • FIG. 3 is a flowchart for explaining an inspection method of the liquid crystal display panel 10 according to the present embodiment.
  • the following steps are performed using the inspection apparatus 100 described above.
  • step S110 the lens 30a of the camera 30 is adjusted to focus on the surface of the liquid crystal display panel 10, and the camera 30 images the liquid crystal display panel 10. That is, the camera 30 obtains image data of the liquid crystal display panel 10 while focusing on the surface of the CF substrate (first substrate) 11.
  • a contrast value (first contrast value) at 22P or position 20P is obtained.
  • the contrast value can be obtained, for example, as a value of 1 to 1000 or a value of 256 gradations (that is, a value of 1 to 256), and the contrast value is used as the contrast intensity index value t1 (first contrast intensity).
  • the index value can be an index value.
  • step S120 the lens 30a of the camera 30 is adjusted to focus on the foreign material 21 on the surface of the liquid crystal display panel 10 (that is, the upper surface of the CF substrate or the first substrate 11).
  • the liquid crystal display panel 10 is imaged.
  • a contrast intensity index value t2 (second contrast intensity index value) is obtained.
  • step S130 the camera 30 adjusts the lens 30a of the camera 30 so that the foreign object 22 on the back surface of the liquid crystal display panel 10 (that is, the lower surface of the TFT substrate or the second substrate 12) is focused.
  • the liquid crystal display panel 10 is imaged.
  • the contrast intensity at the position 21P, 22P or 20P corresponding to the foreign matter 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 and the defect 20 inside the liquid crystal display panel 10 An index value t3 (third contrast intensity index value) is obtained.
  • step S140 the contrast intensity index values t1 to t3 obtained in the above-described steps S110 to S130 are compared to thereby compare the foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 with the defects 20 inside the liquid crystal display panel 10. To distinguish.
  • FIG. 4 is a conceptual diagram of the liquid crystal display panel 10 for explaining the reference of the focus of the camera 30 (or the range of the extension amount of the lens 30a) in the inspection method according to this embodiment.
  • the extension amount of the lens 30a of the camera 30 is set to 0 mm. Further, when focusing (see arrow 51) on the foreign substance 21 on the surface of the liquid crystal display panel 10 (step S120), the extension amount of the lens 30a of the camera 30 is set to -0.10 mm. Further, when focusing (see arrow 52) on the foreign substance 22 on the back surface of the liquid crystal display panel 10 (S130), the extension amount of the lens 30a of the camera 30 is set to +1.50 mm. That is, the extension range of the lens 30a of the camera 30 is ⁇ 0.10 mm or more and +1.50 mm when the surface of the liquid crystal display panel 10 is 0 mm.
  • the focus (50) in step S110 is for detecting the defect 20 inside the liquid crystal display panel 10
  • the focus (50) is the surface of the liquid crystal display panel 10 (that is, the surface of the CF substrate 11).
  • the contrast value (or contrast intensity index value t1) corresponding to the defect 20 inside the liquid crystal display panel 10 is obtained, the focus is on any of the CF substrate 11, the liquid crystal layer 15, and the TFT substrate 12. Can be combined.
  • FIGS. 5A to 5C are conceptual diagrams for specifically explaining the inspection method according to the present embodiment.
  • 5A to 5C the right side shows a drawing of the camera 30 and the liquid crystal display panel 10, and the left side shows image data captured by the camera 30.
  • FIGS. 6A and 6B are a table and a graph showing the relationship between the lens extension amount and the contrast intensity index value in the inspection method of the present embodiment, respectively.
  • 7A and 7B are a table and a graph showing the relationship between the lens extension amount and the relative value from the peak of the contrast intensity index value in the inspection method of the present embodiment, respectively.
  • the extension amount of the lens 30a of the camera 30 is set to 0 mm (see the reference line 35), and the surface of the liquid crystal display panel 10 (for example, the height position of the upper surface of the first substrate 11) is set.
  • the focus point FP (50) is set and the liquid crystal display panel 10 is imaged.
  • bright spots are displayed in the captured image data 40 at, for example, positions 21P, 22P, and 20P.
  • a contrast intensity index value t1 is obtained.
  • the contrast intensity index value t1 is 300 at the position 20P and 350 at the position 21P.
  • the position 22P is 280.
  • the extension amount of the lens 30a of the camera 30 is set to ⁇ 0.10 mm (see the reference line 35a), and the foreign matter 21 on the surface of the liquid crystal display panel 10 (for example, the central height of the foreign matter 21).
  • the focus point FP (51) is set at (position), and the liquid crystal display panel 10 is imaged. That is, as shown by the arrow 36a, the extension amount of the lens 30a of the camera 30 is changed from 0 mm to -0.10 mm.
  • bright spots are displayed in the captured image data 40a, for example, at positions 21P, 22P, and 20P.
  • blurred bright spots are displayed at the positions 22P and 20P.
  • the contrast intensity index value t2 is 200 at the position 20P, the position It is 500 at 21P and 270 at position 22P.
  • the extension amount of the lens 30a of the camera 30 is set to +1.50 mm (see the reference line 35b), and the foreign matter 22 on the back surface of the liquid crystal display panel 10 (for example, the center height of the foreign matter 22).
  • the focus point FP (52) is set at (position), and the liquid crystal display panel 10 is imaged. That is, as shown by the arrow 36b, the extension amount of the lens 30a of the camera 30 is changed from -0.10 mm to +1.50 mm.
  • bright spots are displayed in the captured image data 40b, for example, at positions 21P, 22P, and 20P.
  • blurred bright spots are displayed at the positions 21P and 20P.
  • the contrast intensity index value t3 is 150 at the position 20P and 21P Is 280, and position 22P is 600.
  • the obtained contrast intensity index values t1, t2, and t3 are compared for each of the positions 20P, 21P, and 22P. Specifically, for the contrast intensity index values t1, t2, and t3 at the position 20P, the contrast intensity index value t1 is the largest when the amount of extension of the lens 30a is 0 mm (reference line 35). Therefore, it is determined that the contrast intensity index value at the position 20P indicates the defect 20 inside the liquid crystal display panel 10.
  • the contrast intensity index value t2 is the largest when the amount of extension of the lens 30a is ⁇ 0.10 mm (reference line 35a). Therefore, it is determined that the contrast intensity index value at the position 21P indicates the foreign matter 21 on the surface of the liquid crystal display panel 10.
  • the contrast intensity index value t3 is the largest when the extension amount of the lens 30a is +1.50 mm (reference line 35b). For this reason, the contrast intensity index value at the position 22P is determined to indicate the foreign matter 22 on the back surface of the liquid crystal display panel 10.
  • the foreign substances 21 and 22 and the defect 20 can be easily distinguished from each other by comparing the focus point FP (or the extension amount of the lens 30a) with the contrast intensity index values t1, t2, and t3. .
  • FIG. 6B is a graph showing the relationship between the lens extension amount (mm) obtained above and the contrast intensity index value. As shown in FIG. 6B, a contrast intensity index value curve having a peak at a position 20P (when the lens extension amount is 0 mm) and a peak at a position 21P (when the lens extension amount is ⁇ 0.10 mm). And a contrast intensity index value curve having a peak at the position 22P (when the lens extension amount is +1.50 mm).
  • the distinction between the defect 20 in the liquid crystal display panel 10 and the foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 is more specifically relative to the peaks of the contrast intensity index values t1, t2, and t3. You may carry out based on a value (%).
  • FIG. 7A shows the contrast intensity index values t1, t2, and t3 shown in FIG. 6A described above for each position 20P, 21P, and 22P.
  • the relative values (%) obtained by setting the peak value at each position 20P, 21P, and 22P as 100 are shown.
  • the position 20P is the defect 20 of the liquid crystal display panel 10
  • the position 21P is the foreign material 21 on the surface of the liquid crystal display panel 10
  • the position 22P is on the back surface of the liquid crystal display panel 10. It can be determined that the foreign object 22 is present.
  • FIG. 7B is a graph showing the relationship between the lens feed amount (mm) and the relative value (%) from the peak of the contrast intensity index value.
  • the focus point FP or the lens 30a is extended in consideration of the thicknesses of the first substrate 11 and the second substrate 12, the thickness of the liquid crystal layer 15, and the dimensions of the foreign substances 21 and 22.
  • the amount range is determined. That is, in this example, when the surface of the liquid crystal display panel 10 is 0 mm, the range is ⁇ 0.10 mm or more and +1.50 mm, but is not limited thereto.
  • the focus point FP is adjusted in accordance with actual conditions, that is, in consideration of the thickness of the first substrate 11 and the second substrate 12, the thickness of the liquid crystal layer 15, and the dimensions of the foreign substances 21 and 22.
  • the extension amount of the lens 30a is ⁇ 0.10 mm.
  • the foreign matter 22 on the back surface of the liquid crystal display panel 10 is used. In order to detect this, it is desirable that the extension amount of the lens 30a is +1.50 mm.
  • the contrast intensity index value is a CCD contrast value obtained based on image data picked up by the camera 30, and the contrast value uses not only the maximum value but also an integral value. It is also possible. That is, the integrated value of the contrast value of the CCD at the location where the foreign matter 21 or 22 on the front and back surfaces of the liquid crystal display panel 10 or the internal defect 20 is detected can be used. Contrast values around the foreign matter 21 and 22 or the defect 20 to be formed can be included (integrated) and used as a contrast intensity index value. This will be further described with reference to FIG.
  • FIG. 8 shows a region 25 including a region 25b having a contrast value of 250 surrounded by a region 25a having a contrast value of 60 in the pattern in which the pixels 17 are arranged. It is assumed that foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 or internal defects 20 are present in the region 25b.
  • the contrast intensity index value in the example of FIG. 8, the integral value of the contrast of 730 (60 + 60 + 60 + 60 + 250 + 60 + 60 + 60 + 60 + 60 + 60) obtained by adding the values of the contrast values 60 and 250 (may be referred to as “contrast volume”). Using can make it closer to the judgment of the human eye.
  • the focus points (50) on the front surface (50) of the liquid crystal display panel 10 and the foreign matters (21, 22) on the front and back surfaces (51, 52) of the liquid crystal display panel 10 The surface of the liquid crystal display panel 10 is imaged by adjusting the extension amount of the lens 30a of the camera 30 so that FP) comes.
  • the contrast intensity index values t1 to t3 at the respective focus points obtained on the basis of the captured image data 40, 40a, and 40b are compared to thereby compare the foreign substances 21 and 22 on the front and rear surfaces of the liquid crystal display panel 10 with the internal parts. It can be distinguished from the defect 20.
  • the method for inspecting the liquid crystal display panel according to the present embodiment there is no need to use a complicated automatic inspection apparatus including a conventional dust inspection stage, and the process for inspecting the liquid crystal display panel 10 is performed.
  • the time required for the inspection of the liquid crystal display panel 10 can be shortened.
  • the liquid crystal display panel 10 can be inspected on an existing line or on an existing stage simply by disposing a camera 30 with a variable focus point, without installing a conventional dust inspection stage.
  • Technical significance is great.
  • the contrast intensity index values t1 to t3 are obtained in this order has been described with reference to FIG. 3 or FIG. 5, but the present invention is limited to this embodiment. Is not to be done. In other words, the contrast intensity index values t1 to t3 may be obtained in any order. Regardless of which order is adopted, the contrast intensity index values t1 to t3 can be compared to compare the liquid crystal display panel 10. The foreign matters 21 and 22 on the front and back surfaces can be distinguished from the internal defects 20.
  • FIGS. 9A to 9C are conceptual diagrams for explaining an inspection method according to the second embodiment of the present invention.
  • the right side shows a drawing of the camera 30 and the liquid crystal display panel 10
  • the left side shows image data captured by the camera 30.
  • the configuration of the inspection apparatus 100 according to the present embodiment is different from the configuration of the inspection apparatus 100 according to the first embodiment described above in that three cameras (30, 31, 32) are provided.
  • the other configuration of the inspection apparatus 100 according to the present embodiment is substantially the same as the configuration of the inspection apparatus 100 according to the first embodiment, the description thereof is omitted.
  • the focus points of the three cameras 30, 31, and 32 are set to the surface of the liquid crystal display panel 10, the foreign material 21 on the surface of the liquid crystal display panel 10, and the liquid crystal display panel 10.
  • the front surface of the liquid crystal display panel 10 is photographed by the respective cameras 30, 31, and 32 in accordance with the foreign matter 22 on the back surface.
  • the camera 30 focuses on the surface of the liquid crystal display panel 10 (the amount of extension of the lens 30a is 0 mm) and photographs the surface of the liquid crystal display panel 10.
  • the same image data 40 as in the first embodiment is obtained.
  • the contrast intensity index values t1 of 20P, 21P, and 22P are obtained.
  • the camera 31 focuses on the foreign substance 21 positioned on the surface of the liquid crystal display panel 10 (the lens 31a is fed out at ⁇ 0.10 mm) to photograph the surface of the liquid crystal display panel 10 to obtain the first
  • the same image data 40a as in the embodiment is obtained.
  • the contrast intensity index values t2 of 20P, 21P, and 22P are obtained.
  • the camera 32 focuses on the foreign material 22 positioned on the back surface of the liquid crystal display panel 10 (the lens 32a has a feed amount of +1.50 mm) and photographs the back surface of the liquid crystal display panel 10 to obtain the first
  • the same image data 40b as in the embodiment is obtained.
  • the contrast intensity index values t3 of 20P, 21P, and 22P are obtained.
  • the same processes as described in the first embodiment are performed, so that the foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 and the internal defects 20 Can be distinguished.
  • the liquid crystal display panel inspection method according to the present embodiment further simplifies the process for inspecting the liquid crystal display panel 10 although the number of cameras to be used is increased as compared to the first embodiment. In addition, the time required for the inspection of the liquid crystal display panel 10 can be further shortened.
  • the first to third image data 40, 40a, and 40b are obtained by the camera 30 (or the cameras 30, 31, and 32) at the three focus points. It is also possible to distinguish between the foreign substance 21 and the internal defect 20 by the camera 30 (or the cameras 30 and 31) at one focus point. Specifically, the foreign matter 22 located on the back surface of the liquid crystal display panel 10 is often easily distinguished from the internal defect 20 because of the distance to the surface of the liquid crystal display panel 10. Therefore, by obtaining the contrast value (or contrast intensity index value t1, t2) between the foreign substance 21 located on the surface of the liquid crystal display panel 10 and the internal defect 20, the foreign substance 21 and the internal defect 20 are separated. Separately, as a result, the internal defect 20 can be specified.
  • the contrast value or contrast intensity index value t1, t2
  • the foreign material 22 located on the back surface of the liquid crystal display panel 10 is a reference line which is ⁇ 0.10 mm even when the reference line 35 where the lens 30a of the camera 30 is extended is 0 mm. Even in the case of the line 35a, no peak of the contrast intensity index value occurs. If this peak characteristic is used, it becomes possible to distinguish the foreign substance 21 and the internal defect 20 by imaging with the cameras 30 (or cameras 30, 31) at two focus points. In addition, when the foreign material 22 located on the back surface of the liquid crystal display panel 10 is specified by this method, it is possible to invert the liquid crystal display panel 10 and distinguish the foreign material 22 from the internal defect 20. is there.
  • liquid crystal panel inspection method capable of simplifying the process for inspecting the liquid crystal display panel and shortening the time required for the inspection of the liquid crystal display panel.
  • Liquid crystal display panel 11 Color filter substrate (first substrate) 12 Array substrate (second substrate) 14 Sealing material 15 Liquid crystal layer 17 Pixel 20 Defects 21, 22 Foreign matter 30 Camera 30a Lens 40, 40a, 40b Image data 100 Inspection device 101 Liquid crystal display panel 1000 Inspection device

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Abstract

This inspection method simplifies the process of inspecting a liquid-crystal display panel and shortens the time required to perform an inspection of a liquid-crystal display panel. The method for inspecting a liquid-crystal display panel (10) involves carrying out the following steps: the extension amount of the lens (30a) of a camera (30) is adjusted, the focus is adjusted to foreign matter (21, 22) on the liquid-crystal display panel (10) and on the front and back surfaces thereof, and the surface of the liquid-crystal display panel (10) is imaged; the contrast intensity index values (t1, t2, t3) of positions (21P), (22P), or (20P) corresponding to either the foreign matter (21, 22) on the front and back surfaces of the liquid-crystal display panel (10) or to internal defects (20) in the liquid-crystal display panel (10) are obtained on the basis of each of the captured image data (40, 40a, 40b); and the foreign matter (21, 22) on the front and back surfaces of the liquid-crystal display panel (10) and the internal defects (20) in the liquid-crystal display panel (10) are differentiated by comparing the contrast intensity index values (t1, t2, t3).

Description

液晶表示パネルの検査方法Inspection method of liquid crystal display panel
　本発明は、液晶表示パネルの検査方法に関し、特に、液晶パネルの内部における欠陥の有無を検査するための検査方法に関する。
　なお、本出願は２０１１年１１月２５日に出願された日本国特許出願２０１１－２５６９７６号に基づく優先権を主張しており、その出願の全内容は本明細書中に参照として組み入れられている。 The present invention relates to an inspection method for a liquid crystal display panel, and more particularly to an inspection method for inspecting the presence or absence of a defect in a liquid crystal panel.
Note that this application claims priority based on Japanese Patent Application No. 2011-256976 filed on November 25, 2011, the entire contents of which are incorporated herein by reference. .
　近年、より高品位な画像表示が可能な液晶表示パネルが強く要望されている。しかしながら、現在の液晶表示パネルの製造技術では、表示欠陥の発生を防止することは困難である。このため、表示欠陥の低減された高品位の液晶表示パネルを提供するために、製造工程において、表示欠陥検査（画質検査）工程が行われている。 In recent years, there has been a strong demand for liquid crystal display panels capable of displaying higher-quality images. However, it is difficult to prevent the occurrence of display defects with the current liquid crystal display panel manufacturing technology. For this reason, in order to provide a high-quality liquid crystal display panel with reduced display defects, a display defect inspection (image quality inspection) process is performed in the manufacturing process.
　例えば、輝点（異常点灯）不良、黒点（不点灯）不良といった表示パネルの表示欠陥の有無の検査工程は、検査員の目視によって行われるのが一般的である。検査員による目視検査工程は、良品として扱うことができる最低品位のサンプルである限界サンプルを用いて行われる。より具体的には、液晶表示パネルと限界サンプルとを検査員が見比べることにより、合否（表示欠陥の有無）の判定が行われる。 For example, the inspection process for the presence or absence of display defects on the display panel, such as a bright spot (abnormal lighting) failure or a black spot (non-lighting) failure, is generally performed by an inspector. The visual inspection process by the inspector is performed using a limit sample which is a sample of the lowest quality that can be handled as a non-defective product. More specifically, the pass / fail (presence / absence of display defect) is determined by the inspector comparing the liquid crystal display panel and the limit sample.
　しかしながら、目視検査工程では、各検査員の間で合否判定結果がばらつくという問題や、同一検査員による検査であっても日時、検査環境によって合否判定結果がばらつくという問題がある。さらには、目視検査工程では、マンパワーを必要とするため、液晶表示パネルの製造コストが上昇するという問題がある。 However, in the visual inspection process, there are problems that the pass / fail judgment results vary among inspectors, and that the pass / fail judgment results vary depending on the date and time and the inspection environment even if the inspection is performed by the same inspector. Furthermore, since the visual inspection process requires manpower, there is a problem that the manufacturing cost of the liquid crystal display panel increases.
　そこで、このような問題に鑑み、液晶表示パネルの表示欠陥の自動検査方法が種々提案されている。例えば、液晶表示パネルをバックライトで照らし、液晶表示パネルの欠陥を撮像装置（例えば、ＣＣＤカメラ）により撮像することにより、液晶表示パネルの表示欠陥の有無を検査する方法が提案されている。 In view of such problems, various automatic inspection methods for display defects of liquid crystal display panels have been proposed. For example, a method has been proposed in which a liquid crystal display panel is illuminated with a backlight, and defects in the liquid crystal display panel are imaged with an imaging device (for example, a CCD camera) to inspect the presence or absence of display defects in the liquid crystal display panel.
　図１０は、従来の液晶表示パネルの検査装置１０００の構成を示しており、この自動検査装置１０００によれば、液晶表示パネル１０１の欠陥の有無を自動で検査することができる（例えば、特許文献１参照）。 FIG. 10 shows a configuration of a conventional liquid crystal display panel inspection apparatus 1000. According to this automatic inspection apparatus 1000, the presence or absence of defects in the liquid crystal display panel 101 can be automatically inspected (for example, Patent Literature 1). 1).
　図１０に示した検査装置１０００では、異物検出部２００において、液晶表示パネル１０１を搬送させながら、液晶表示パネル１０１の表裏面１０１ａ、１０１ｂに照射ランプ４００による照射光２９０を照射させる。その状態で、反射光３２０、３３０を受光するラインセンサー５００によって、液晶表示パネル１０１の表裏面１０１ａ、１０１ｂの第１画像データを撮像する。撮像された第１画像データに基づいて、画像処理装置１５０を介して、液晶表示パネル１０１の表裏面１０１ａ、１０１ｂにおける輝点の位置を取得する。なお、画像処理装置１５０は、Ａ／Ｄコンバータ１６０、位置データ算出部１７０、記憶部１８０及び欠陥検出部１９０から構成されている。 In the inspection apparatus 1000 shown in FIG. 10, the foreign object detection unit 200 irradiates the front and back surfaces 101 a and 101 b of the liquid crystal display panel 101 with the irradiation light 290 from the irradiation lamp 400 while transporting the liquid crystal display panel 101. In this state, the first image data on the front and back surfaces 101a and 101b of the liquid crystal display panel 101 is captured by the line sensor 500 that receives the reflected lights 320 and 330. Based on the captured first image data, the positions of bright spots on the front and back surfaces 101a and 101b of the liquid crystal display panel 101 are acquired via the image processing device 150. The image processing device 150 includes an A / D converter 160, a position data calculation unit 170, a storage unit 180, and a defect detection unit 190.
　次に、表示欠陥検出部３００において、検査用テーブル１２０に搭載した液晶表示パネル１０１に対してバックライト１１０による照射光３９０を照射させる。その状態で、カメラ１４０により、液晶表示パネル１０１の内部と表裏面１０１ａ、１０１ｂの第２画像データを撮像する。同様に、撮像された第２画像データに基づいて、画像処理装置１５０を介して、液晶表示パネル１０１の内部と表裏面１０１ａ、１０１ｂにおける輝点の位置を取得する。 Next, the display defect detection unit 300 irradiates the liquid crystal display panel 101 mounted on the inspection table 120 with the irradiation light 390 from the backlight 110. In this state, the camera 140 captures the second image data of the inside of the liquid crystal display panel 101 and the front and back surfaces 101a and 101b. Similarly, the positions of bright spots in the liquid crystal display panel 101 and on the front and back surfaces 101a and 101b are acquired via the image processing device 150 based on the captured second image data.
　次に、第１画像データにおける輝点の位置と第２画像データにおける輝点の位置を比較することにより、液晶表示パネル１０１の内部の欠陥３４０に基づく輝点と液晶表示パネル１０１の表裏面の異物３００、３１０に基づく輝点とを区別する。これにより、液晶表示パネル１０１の内部に欠陥があるか否かを検出することができる。 Next, by comparing the position of the bright spot in the first image data and the position of the bright spot in the second image data, the bright spot based on the defect 340 inside the liquid crystal display panel 101 and the front and back surfaces of the liquid crystal display panel 101 are compared. A bright spot based on the foreign matters 300 and 310 is distinguished. Thereby, it is possible to detect whether or not there is a defect inside the liquid crystal display panel 101.
特開２０１１－００２９２４号公報JP 2011-002924 A
　しかしながら、図１０に示した液晶表示パネル１０１の検査方法では、液晶表示パネル１０１を搬送させながら、照射ランプ４００による照射光を液晶表示パネルの表裏面に照射させた状態で、ラインセンサーにより、液晶表示パネル１０１の表裏面１０１ａ、１０１ｂの画像データを撮像する必要がある。このため、液晶表示パネル１０１の検査に用いる検査装置１０００の構造が複雑化すると共に、その検査を行う際の工程が複雑化するという問題がある。さらに、この検査工程では、液晶表示パネル１０１の検査に長時間を要するという問題があった。 However, in the method for inspecting the liquid crystal display panel 101 shown in FIG. 10, the liquid crystal display panel 101 is conveyed and the liquid crystal display panel 101 is irradiated with light irradiated by the irradiation lamp 400 on the front and back surfaces of the liquid crystal display panel. It is necessary to capture image data of the front and back surfaces 101a and 101b of the display panel 101. For this reason, there is a problem that the structure of the inspection apparatus 1000 used for the inspection of the liquid crystal display panel 101 is complicated and the process for performing the inspection is complicated. Further, this inspection process has a problem that it takes a long time to inspect the liquid crystal display panel 101.
　本発明はかかる点に鑑みてなされたものであり、その主な目的は、液晶表示パネルの検査を行う際の工程を簡素化すると共に、液晶表示パネルの検査に要する時間を短縮化する液晶表示パネルの検査方法を提供することである。 The present invention has been made in view of the above points, and its main purpose is to simplify a process for inspecting a liquid crystal display panel and to shorten a time required for inspecting the liquid crystal display panel. It is to provide a panel inspection method.
　本発明に係る検査方法は、第１基板と、前記第１基板に対向して配置された第２基板と、前記第１基板と前記第２基板との間に設けられた液晶層とを備える液晶表示パネルの検査方法である。本発明に係る検査方法は、前記液晶パネルにおける前記第1基板、前記液晶層および前記第２基板のいずれかにフォーカスを合わせるようにカメラによって前記液晶表示パネルの第1画像データを撮像し、前記第1の画像データに基づいて、前記第1基板の表面および前記第２基板の裏面に存在し得る異物に対応する位置、および、前記液晶パネルの内部の欠陥に対応する位置における第１コントラスト値を得る工程（ａ）と、前記第１基板の表面に存在し得る異物にフォーカスを合わせるように前記カメラによって前記液晶表示パネルの第２画像データを撮像し、前記第２の画像データに基づいて、前記第1基板の表面および前記第２基板の裏面に存在し得る異物に対応する位置、および、前記液晶パネルの内部の欠陥に対応する位置における第２コントラスト値を得る工程（ｂ）と、前記第２基板の裏面に存在し得る異物にフォーカスを合わせるように前記カメラによって前記液晶表示パネルの第３画像データを撮像し、前記第３画像データに基づいて、前記第1基板の表面および前記第２基板の裏面に存在し得る異物に対応する位置、および、前記液晶パネルの内部の欠陥に対応する位置における第３コントラスト値を得る工程（ｃ）と、前記第１から第３コントラスト値を対比することによって、前記異物と前記欠陥とを区別する工程（ｄ）を含む。 An inspection method according to the present invention includes a first substrate, a second substrate disposed to face the first substrate, and a liquid crystal layer provided between the first substrate and the second substrate. This is an inspection method for a liquid crystal display panel. In the inspection method according to the present invention, the first image data of the liquid crystal display panel is captured by a camera so as to focus on any of the first substrate, the liquid crystal layer, and the second substrate in the liquid crystal panel, Based on the first image data, a first contrast value at a position corresponding to a foreign substance that may exist on the front surface of the first substrate and the back surface of the second substrate, and a position corresponding to a defect inside the liquid crystal panel And taking the second image data of the liquid crystal display panel with the camera so as to focus on the foreign matter that may be present on the surface of the first substrate, and based on the second image data , A position corresponding to a foreign substance that may be present on the front surface of the first substrate and the back surface of the second substrate, and a position corresponding to a defect inside the liquid crystal panel. Step (b) of obtaining a contrast value, and imaging the third image data of the liquid crystal display panel by the camera so as to focus on a foreign substance that may exist on the back surface of the second substrate, and based on the third image data (C) obtaining a third contrast value at a position corresponding to a foreign substance that may be present on the front surface of the first substrate and the back surface of the second substrate, and a position corresponding to a defect inside the liquid crystal panel; And (d) distinguishing the foreign matter from the defect by comparing the first to third contrast values.
　ある好適な実施形態において、前記工程（ａ）から前記工程（ｃ）における前記フォーカスを合わせることは、前記カメラのレンズの繰り出し量を調整することによって実行される。 In a preferred embodiment, the focusing from the step (a) to the step (c) is performed by adjusting a drawing amount of the lens of the camera.
　ある好適な実施形態において、前記カメラは、一台のカメラであり、前記工程（ａ）において、前記フォーカスは、前記第１基板の表面を基準に合わせられる。 In a preferred embodiment, the camera is a single camera, and in the step (a), the focus is adjusted based on the surface of the first substrate.
　ある好適な実施形態において、前記カメラは、三台のカメラであり、前記工程（ａ）から（ｃ）における第１から第３画像データは、それぞれのフォーカスが異なる前記三台のカメラによって同一工程にて撮像される。 In a preferred embodiment, the cameras are three cameras, and the first to third image data in the steps (a) to (c) are the same step by the three cameras having different focus. The image is taken.
　ある好適な実施形態において、前記第１から第３コントラスト値は、それぞれ、前記第１から第３の画像データにおける前記異物及び前記欠陥に対応する位置のコントラストの積分値を指標にしている。 In a preferred embodiment, each of the first to third contrast values uses an integral value of a contrast at a position corresponding to the foreign matter and the defect in the first to third image data as an index.
　ある好適な実施形態では、前記工程（ｄ）において、前記異物及び前記欠陥のいずれかが存在する第１位置における前記第１から第３コントラスト値を対比することによって、前記第１コントラスト値が最も大きい場合には、前記第１位置には前記欠陥が存在すると判定することを実行する。 In a preferred embodiment, in the step (d), the first contrast value is most determined by comparing the first to third contrast values at a first position where any of the foreign matter and the defect exists. If larger, it is determined that the defect exists at the first position.
　ある好適な実施形態では、前記工程（ｄ）において、前記異物及び前記欠陥のいずれかが存在する第２位置における前記第１から第３コントラスト値を対比することによって、前記第２コントラスト値が最も大きい場合には、前記第２位置には前記異物が存在すると判定し、前記異物及び前記欠陥のいずれかが存在する第３位置における前記第１から第３コントラスト値を対比することによって、前記第３コントラスト値が最も大きい場合には、前記第３位置には前記異物が存在すると判定することを実行する。 In a preferred embodiment, in the step (d), the second contrast value is the highest by comparing the first to third contrast values at the second position where either the foreign matter or the defect exists. If larger, it is determined that the foreign matter is present at the second position, and the first to third contrast values at the third position where either the foreign matter or the defect exists are compared, thereby When the 3 contrast value is the largest, it is determined that the foreign matter is present at the third position.
　ある好適な実施形態では、前記工程（ｄ）においては、前記第１から第３コントラスト値のピークからの相対値を用いて、前記異物と前記欠陥とを区別することを実行する。 In a preferred embodiment, in the step (d), the relative value from the peak of the first to third contrast values is used to distinguish the foreign matter from the defect.
　ある好適な実施形態において、前記カメラは、ＣＣＤカメラ又はＣＭＯＳカメラであり、前記異物は、搬送ローラーの削りカス、洗浄ブラシの削りカス、および、分断機のガラスのカスからなる群から選択される少なくとも一つである。 In a preferred embodiment, the camera is a CCD camera or a CMOS camera, and the foreign matter is selected from the group consisting of a scraping scrap of a transport roller, a scraping scrap of a cleaning brush, and a scrap of a glass of a cutting machine. At least one.
　本発明に係る他の検査方法は、第１基板と、前記第１基板に対向して配置された第２基板と、前記第１基板と前記第２基板との間に設けられた液晶層とを備える液晶表示パネルの検査方法である。前記液晶パネルにおける前記第1基板、前記液晶層および前記第２基板のいずれかにフォーカスを合わせるようにカメラによって前記液晶表示パネルの第1画像データを撮像し、前記第1の画像データに基づいて、前記第1基板の表面に存在し得る異物に対応する位置、および、前記液晶パネルの内部の欠陥に対応する位置における第１コントラスト値を得る工程と、前記第１基板の表面に存在し得る異物にフォーカスを合わせるように前記カメラによって前記液晶表示パネルの第２画像データを撮像し、前記第２の画像データに基づいて、前記第1基板の表面に存在し得る異物に対応する位置、および、前記液晶パネルの内部の欠陥に対応する位置における第２コントラスト値を得る工程と、前記第１および第２コントラスト値を対比することによって、前記異物と前記欠陥とを区別する工程を含む。 Another inspection method according to the present invention includes a first substrate, a second substrate disposed opposite to the first substrate, a liquid crystal layer provided between the first substrate and the second substrate, A liquid crystal display panel inspection method comprising: First image data of the liquid crystal display panel is picked up by a camera so as to focus on any of the first substrate, the liquid crystal layer, and the second substrate in the liquid crystal panel, and based on the first image data Obtaining a first contrast value at a position corresponding to a foreign substance that may be present on the surface of the first substrate and a position corresponding to a defect inside the liquid crystal panel; and may be present on the surface of the first substrate. The second image data of the liquid crystal display panel is imaged by the camera so as to focus on the foreign matter, and the position corresponding to the foreign matter that may be present on the surface of the first substrate based on the second image data, and The step of obtaining a second contrast value at a position corresponding to a defect inside the liquid crystal panel is compared with the first and second contrast values. , Comprising the step distinguishes the said and the foreign substance defect.
　本発明に係る検査方法によれば、カメラのフォーカスを変えて液晶表示パネルにおける第１から第３画像データを撮像し、それらの画像データから第１から第３コントラスト値を得て、第１から第３コントラスト値を対比することによって、液晶表示パネルの表裏面に位置する異物と、液晶表示パネルの内部の欠陥とを区別することができる。その結果、液晶表示パネルの検査を行う際の工程を簡素化すると共に、液晶表示パネルの検査に要する時間を短縮化することができる。 According to the inspection method of the present invention, the first to third image data in the liquid crystal display panel is picked up by changing the focus of the camera, the first to third contrast values are obtained from the image data, and the first to third image data are obtained. By comparing the third contrast value, it is possible to distinguish foreign matters located on the front and back surfaces of the liquid crystal display panel from defects inside the liquid crystal display panel. As a result, the process for inspecting the liquid crystal display panel can be simplified, and the time required for inspecting the liquid crystal display panel can be shortened.
（ａ）は、本発明の第１の実施形態に係る検査装置１００の構成を示す図であり、（ｂ）は、検査装置１００のカメラ３０で撮像された画像データの例を説明するための図である。(A) is a figure which shows the structure of the test | inspection apparatus 100 which concerns on the 1st Embodiment of this invention, (b) is for demonstrating the example of the image data imaged with the camera 30 of the test | inspection apparatus 100 FIG. 本発明の第１の実施形態に係る検査装置１００によって検査される液晶表示パネル１０の構成を示す断面図である。It is sectional drawing which shows the structure of the liquid crystal display panel 10 test | inspected by the test | inspection apparatus 100 which concerns on the 1st Embodiment of this invention. 本発明の第１の実施形態に係る検査方法を説明するためのフローチャートである。It is a flowchart for demonstrating the inspection method which concerns on the 1st Embodiment of this invention. 本発明の第１の実施形態に係る検査方法におけるフォーカスの基準を説明するための概念図である。It is a conceptual diagram for demonstrating the focus reference | standard in the inspection method which concerns on the 1st Embodiment of this invention. （ａ）から（ｃ）は、本発明の第１の実施形態に係る検査方法を説明するための概念図である。(A) to (c) is a conceptual diagram for explaining an inspection method according to the first embodiment of the present invention. （ａ）及び（ｂ）は、本発明の第１の実施形態に係る液晶表示パネルの検査方法におけるレンズ繰り出し量とコントラスト強度指標値との関係を示す表及びグラフである。(A) And (b) is the table | surface and graph which show the relationship between the lens extension amount and contrast intensity index value in the test | inspection method of the liquid crystal display panel which concerns on the 1st Embodiment of this invention. （ａ）及び（ｂ）は、本発明の第１の実施形態に係る検査方法におけるレンズ繰り出し量とコントラスト強度指標値のピークからの相対値との関係を示す表及びグラフである。(A) And (b) is the table | surface and graph which show the relationship between the lens extension amount in the inspection method which concerns on the 1st Embodiment of this invention, and the relative value from the peak of contrast intensity index value. 本発明の第１の実施形態に係る検査方法におけるコントラスト強度指標値を説明するための概念図である。It is a conceptual diagram for demonstrating the contrast intensity | strength index value in the inspection method which concerns on the 1st Embodiment of this invention. （ａ）から（ｃ）は、本発明の第２の実施形態に係る液晶表示パネルの検査方法を説明するための概念図である。(A) to (c) is a conceptual diagram for explaining an inspection method for a liquid crystal display panel according to a second embodiment of the present invention. 従来の液晶表示パネルの欠陥の有無を検査するための自動検査装置の構成を示す概念図である。It is a conceptual diagram which shows the structure of the automatic test | inspection apparatus for test | inspecting the presence or absence of the defect of the conventional liquid crystal display panel.
　図面を参照しながら、本発明の好適ないくつかの実施形態を説明する。なお、本明細書において特に言及している事項以外の事柄であって本発明の実施に必要な事柄（例えば、液晶表示パネルの構成や構築方法）は、当該分野における従来技術に基づく当業者の設計事項として把握され得る。本発明は、本明細書に開示されている内容と当該分野における技術常識とに基づいて実施することができる。 Several preferred embodiments of the present invention will be described with reference to the drawings. Note that matters other than the matters specifically mentioned in the present specification and necessary for the implementation of the present invention (for example, the configuration and construction method of the liquid crystal display panel) can be obtained by those skilled in the art based on the prior art in this field. It can be grasped as a design matter. The present invention can be carried out based on the contents disclosed in the present specification and common general technical knowledge in the field.
　以下、図１から図９を参照しながら、本発明の好ましい各実施形態について説明する。なお、以下の図面において、同じ作用を奏する部材、部位には同じ符号を付し、重複する説明は省略又は簡略化することがある。また、各図における寸法関係（長さ、幅、厚さ等）は、必ずしも実際の寸法関係を正確に反映するものではない。また、図中のハッチングは、構成要素の把握のし易さを主な目的として付しており、必ずしも材料の要素を表現するものではない。また、本発明は、以下の実施形態に限定されるものではない。 Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. In addition, in the following drawings, the same code | symbol is attached | subjected to the member and site | part which show the same effect | action, and the overlapping description may be abbreviate | omitted or simplified. In addition, the dimensional relationship (length, width, thickness, etc.) in each drawing does not necessarily accurately reflect the actual dimensional relationship. In addition, hatching in the drawing is given mainly for the purpose of easy understanding of the constituent elements, and does not necessarily represent the elements of the material. The present invention is not limited to the following embodiment.
＜第１の実施形態＞
　図１（ａ）は、本発明の実施形態に係る検査装置１００の構成を模式的に示している。本実施形態の検査装置１００は、液晶表示パネル１０の欠陥の有無を検査するための自動検査装置であり、液晶表示パネル１０の上方には、液晶表示パネル１０の表面を撮像するカメラ３０が配置されている。図１（ｂ）は、カメラ３０のレンズ３０ａによって撮像された画像データ４０の例を示す概念図である。また、図２は、本実施形態の検査装置１００によって検査される液晶表示パネル１０の構成を説明するための断面図である。 <First Embodiment>
Fig.1 (a) has shown typically the structure of the test | inspection apparatus 100 which concerns on embodiment of this invention. The inspection apparatus 100 of the present embodiment is an automatic inspection apparatus for inspecting the presence or absence of defects in the liquid crystal display panel 10, and a camera 30 that images the surface of the liquid crystal display panel 10 is disposed above the liquid crystal display panel 10. Has been. FIG. 1B is a conceptual diagram illustrating an example of image data 40 captured by the lens 30 a of the camera 30. FIG. 2 is a cross-sectional view for explaining the configuration of the liquid crystal display panel 10 inspected by the inspection apparatus 100 of the present embodiment.
　本実施形態の検査装置（自動検査装置）１００は、液晶表示パネル１０の表裏面における埃またはごみ等の異物２１、２２と、液晶表示パネル１０の内部に存在する欠陥２０とを区別する装置である。本実施形態の検査装置１００では、カメラ３０を用いて、そのレンズ３０ａの繰り出し量を調節しながら、液晶表示パネル１０を撮像し、撮像された画像データ４０に基づいて、液晶表示パネル１０の表裏面の異物２１、２２と液晶表示パネル１０の内部に存在する欠陥（または微小欠陥）２０とを区別する構成となっている。 An inspection apparatus (automatic inspection apparatus) 100 according to the present embodiment is an apparatus that distinguishes foreign matters 21 and 22 such as dust or dust on the front and back surfaces of the liquid crystal display panel 10 from defects 20 existing inside the liquid crystal display panel 10. is there. In the inspection apparatus 100 of the present embodiment, the camera 30 is used to image the liquid crystal display panel 10 while adjusting the extension amount of the lens 30a, and the surface of the liquid crystal display panel 10 is displayed based on the captured image data 40. In this configuration, foreign substances 21 and 22 on the back surface and defects (or micro defects) 20 existing inside the liquid crystal display panel 10 are distinguished.
　図１（ｂ）に示すように、カメラ３０によって液晶表示パネル１０が撮像された画像データ４０には、異物２１、２２又は欠陥２０に対応する位置２１Ｐ（第１位置）、位置２２Ｐ（第２位置）又は位置２０Ｐ（第３位置）の点が表示されている。この例では、これらの位置（２１Ｐ、２２Ｐ、２０Ｐ）においては、異物２１、２２又は欠陥２０の存在によって、その他の領域よりも明るい輝点が表示されることになる。 As shown in FIG. 1B, the image data 40 obtained by imaging the liquid crystal display panel 10 by the camera 30 includes a position 21P (first position) and a position 22P (second position) corresponding to the foreign matter 21, 22 or the defect 20. Position) or a point at position 20P (third position) is displayed. In this example, at these positions (21P, 22P, 20P), bright spots brighter than other regions are displayed due to the presence of the foreign matter 21, 22 or the defect 20.
　本実施形態において、液晶表示パネル１０の表裏面の埃又はごみである異物２１、２２としては、例えば、搬送ローラーの削りカス、洗浄ブラシの削りカス、分断機のガラスのカスなどが挙げられる。また、液晶表示パネル１０の内部の欠陥２０としては、例えば、パネル内異物（絶縁体粉末、金属粉末など）、または、配向膜の欠陥（例えば、ポリイミドが塗布されていない箇所、所謂ＰＩはじき）が挙げられる。 In this embodiment, the foreign substances 21 and 22 which are dust or dirt on the front and back surfaces of the liquid crystal display panel 10 include, for example, a scraped scrap of a transport roller, a scraped scrap of a cleaning brush, a scrap of a glass of a cutting machine, and the like. Further, as the defects 20 inside the liquid crystal display panel 10, for example, foreign matter in the panel (insulator powder, metal powder, etc.) or alignment film defects (for example, locations where polyimide is not applied, so-called PI repellency) Is mentioned.
　また、本実施形態の検査装置１００で検査される液晶表示パネル１０は、図２に示すように、カメラ３０側に配置されたカラーフィルタ基板（第１基板）１１と、カラーフィルタ基板１１に対向して配置されたアレイ基板１２とから構成されている。アレイ基板１２には、スイッチング素子（例えば、薄膜トランジスタ（ＴＦＴ））が形成されており、アレイ基板１２をＴＦＴ基板と称することがある。また、カラーフィルタ基板１１には、各画素に対応して赤（Ｒ）・緑（Ｇ）・青（Ｂ）の着色層が形成されており、カラーフィルタ基板１１をＣＦ基板と称することがある。なお、４原色（赤（Ｒ）・緑（Ｇ）・青（Ｂ）・黄（Ｙ））のカラーフィルタ基板１１を用いることができる。加えて、アレイ基板１２側に着色層が設けられる場合には、第１基板１１には着色層は存在しなくなるが、本実施形態の検査方法はその場合でも適用することが可能である。 Further, as shown in FIG. 2, the liquid crystal display panel 10 inspected by the inspection apparatus 100 of the present embodiment is opposed to the color filter substrate (first substrate) 11 disposed on the camera 30 side and the color filter substrate 11. And the array substrate 12 arranged in this manner. A switching element (for example, a thin film transistor (TFT)) is formed on the array substrate 12, and the array substrate 12 may be referred to as a TFT substrate. The color filter substrate 11 is provided with red (R), green (G), and blue (B) colored layers corresponding to each pixel, and the color filter substrate 11 may be referred to as a CF substrate. . Note that the color filter substrate 11 of four primary colors (red (R), green (G), blue (B), and yellow (Y)) can be used. In addition, when a colored layer is provided on the array substrate 12 side, the colored layer is not present on the first substrate 11, but the inspection method of the present embodiment can be applied even in that case.
　ＣＦ基板（第１基板）１１とＴＦＴ基板（第２基板）１２との間には、表示媒体層である液晶層１５が設けられている。液晶層は、ＣＦ基板１１およびＴＦＴ基板１２の間の電界印加に伴って光学特定が変化する液晶材料からなる。本実施形態の液晶表示パネル１０は、概して、全体として矩形の形状を有しており、ＣＦ基板（第１基板）１１とＴＦＴ基板（第２基板）１２は、それぞれ、透光性基板（ガラス基板）から構成されている。 A liquid crystal layer 15 as a display medium layer is provided between the CF substrate (first substrate) 11 and the TFT substrate (second substrate) 12. The liquid crystal layer is made of a liquid crystal material whose optical characteristics change with application of an electric field between the CF substrate 11 and the TFT substrate 12. The liquid crystal display panel 10 of the present embodiment generally has a rectangular shape as a whole, and the CF substrate (first substrate) 11 and the TFT substrate (second substrate) 12 are each a translucent substrate (glass). Substrate).
　さらに、液晶表示パネル１０には、ＣＦ基板１１とＴＦＴ基板１２とを互いに接着するとともに液晶層１５を封入するために枠上に設けられたシール材１４が形成されている。シール材１４は、液晶層１５を周回するように形成されており、ＣＦ基板１１とＴＦＴ基板１２とは、このシール材１４を介して相互に貼り合わされている。また、ＣＦ基板１１は、表示面側（この例では、上側またはカメラ３０側）に配置されている。 Furthermore, the liquid crystal display panel 10 is formed with a sealing material 14 provided on the frame for adhering the CF substrate 11 and the TFT substrate 12 to each other and enclosing the liquid crystal layer 15. The sealing material 14 is formed so as to go around the liquid crystal layer 15, and the CF substrate 11 and the TFT substrate 12 are bonded to each other via the sealing material 14. The CF substrate 11 is disposed on the display surface side (in this example, the upper side or the camera 30 side).
　本実施形態のカメラ３０は、ＣＣＤカメラであり、複数のＣＣＤ（charge-coupled device：電荷結合素子）から構成されている。カメラ（ＣＣＤカメラ）３０に光が入射すると、入射した光量に応じてＣＣＤに電荷が蓄積される。そして、カメラ３０に設けられた複数のＣＣＤのそれぞれに蓄積された電荷量に基づいて、図１（ｂ）に示すように、撮像された画像データ４０を表示することができる。なお、カメラ３０は、ＣＣＤカメラに限らず、他のカメラ（例えば、ＣＭＯＳカメラ）を用いることも可能である。また、カメラ３０には、繰り出し量を変更できるレンズ３０ａが設けられており、このレンズ３０ａによってフォーカス（焦点）の距離を変更することができる。 The camera 30 of the present embodiment is a CCD camera and is composed of a plurality of CCDs (charge-coupled devices). When light enters the camera (CCD camera) 30, charges are accumulated in the CCD in accordance with the amount of incident light. Then, based on the charge amount accumulated in each of the plurality of CCDs provided in the camera 30, as shown in FIG. 1B, the captured image data 40 can be displayed. The camera 30 is not limited to a CCD camera, and other cameras (for example, a CMOS camera) can be used. Further, the camera 30 is provided with a lens 30a that can change the feed amount, and the distance of the focus (focal point) can be changed by the lens 30a.
　図３は、本実施形態に係る液晶表示パネル１０の検査方法を説明するためのフローチャートである。本実施形態に係る検査方法では、上述した検査装置１００を用いて、以下の各工程が実行される。 FIG. 3 is a flowchart for explaining an inspection method of the liquid crystal display panel 10 according to the present embodiment. In the inspection method according to the present embodiment, the following steps are performed using the inspection apparatus 100 described above.
　まず、ステップＳ１１０では、カメラ３０のレンズ３０ａを調節して、液晶表示パネル１０の表面にフォーカスを合わせ、カメラ３０によって液晶表示パネル１０を撮像する。すなわち、ＣＦ基板（第１基板）１１の表面にフォーカスを合わせて、カメラ３０にて液晶表示パネル１０の画像データを得る。 First, in step S110, the lens 30a of the camera 30 is adjusted to focus on the surface of the liquid crystal display panel 10, and the camera 30 images the liquid crystal display panel 10. That is, the camera 30 obtains image data of the liquid crystal display panel 10 while focusing on the surface of the CF substrate (first substrate) 11.
　次いで、撮像された画像データ（第１画像データ）４０に基づいて、液晶表示パネル１０の表裏面の異物２１、２２及び液晶表示パネル１０の内部の欠陥２０のいずれかに対応する位置２１Ｐ、位置２２Ｐ又は位置２０Ｐにおけるコントラスト値（第１コントラスト値）を得る。コントラスト値は、例えば、１～１０００の値、または、２５６階調の値で得ることができ（すなわち、１～２５６の値）で、そのコントラスト値を、コントラスト強度指標値ｔ１（第１コントラスト強度指標値）として、指標値にすることができる。 Next, based on the imaged image data (first image data) 40, a position 21 </ b> P corresponding to any of the foreign matters 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 and the defect 20 inside the liquid crystal display panel 10. A contrast value (first contrast value) at 22P or position 20P is obtained. The contrast value can be obtained, for example, as a value of 1 to 1000 or a value of 256 gradations (that is, a value of 1 to 256), and the contrast value is used as the contrast intensity index value t1 (first contrast intensity). The index value can be an index value.
　次に、ステップＳ１２０では、カメラ３０のレンズ３０ａを調節して、液晶表示パネル１０の表面（すなわち、ＣＦ基板または第１基板１１の上面）の異物２１にフォーカスを合わせるようにして、カメラ３０によって液晶表示パネル１０を撮像する。撮像された画像データ４０ａ（第２画像データ）に基づいて、液晶表示パネル１０の表裏面の異物２１、２２及び液晶表示パネル１０の内部の欠陥２０のいずれかに対応する位置２１Ｐ、２２Ｐ又は２０Ｐにおけるコントラスト強度指標値ｔ２（第２コントラスト強度指標値）を得る。 Next, in step S120, the lens 30a of the camera 30 is adjusted to focus on the foreign material 21 on the surface of the liquid crystal display panel 10 (that is, the upper surface of the CF substrate or the first substrate 11). The liquid crystal display panel 10 is imaged. Based on the imaged image data 40a (second image data), positions 21P, 22P, or 20P corresponding to any of the foreign matters 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 and the defect 20 inside the liquid crystal display panel 10. A contrast intensity index value t2 (second contrast intensity index value) is obtained.
　続いて、ステップＳ１３０では、カメラ３０のレンズ３０ａを調節して、液晶表示パネル１０の裏面（すなわち、ＴＦＴ基板または第２基板１２の下面）の異物２２にフォーカスを合わせるようにして、カメラ３０によって液晶表示パネル１０を撮像する。撮像された画像データ４０ｂ（第３画像データ）に基づいて、液晶表示パネル１０の表裏面の異物２１、２２及び液晶表示パネル１０の内部の欠陥２０に対応する位置２１Ｐ、２２Ｐ又は２０Ｐにおけるコントラスト強度指標値ｔ３（第３コントラスト強度指標値）を得る。 Subsequently, in step S130, the camera 30 adjusts the lens 30a of the camera 30 so that the foreign object 22 on the back surface of the liquid crystal display panel 10 (that is, the lower surface of the TFT substrate or the second substrate 12) is focused. The liquid crystal display panel 10 is imaged. Based on the imaged image data 40b (third image data), the contrast intensity at the position 21P, 22P or 20P corresponding to the foreign matter 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 and the defect 20 inside the liquid crystal display panel 10 An index value t3 (third contrast intensity index value) is obtained.
　その後、ステップＳ１４０では、上述のステップＳ１１０～Ｓ１３０で求めたコントラスト強度指標値ｔ１～ｔ３を対比することによって、液晶表示パネル１０の表裏面の異物２１、２２と液晶表示パネル１０の内部の欠陥２０とを区別する。 Thereafter, in step S140, the contrast intensity index values t1 to t3 obtained in the above-described steps S110 to S130 are compared to thereby compare the foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 with the defects 20 inside the liquid crystal display panel 10. To distinguish.
　図４から図７も参照しながらさらに説明を続ける。図４は、本実施形態に係る検査方法におけるカメラ３０のフォーカスの基準（または、レンズ３０ａの繰り出し量の範囲）を説明するための液晶表示パネル１０の概念図である。 Further explanation will be continued with reference to FIGS. FIG. 4 is a conceptual diagram of the liquid crystal display panel 10 for explaining the reference of the focus of the camera 30 (or the range of the extension amount of the lens 30a) in the inspection method according to this embodiment.
　本実施形態では、図４に示すように、液晶表示パネル１０の表面にフォーカス（矢印５０参照）を合わせる場合（ステップＳ１１０）には、カメラ３０のレンズ３０ａの繰り出し量を０ｍｍとしている。また、液晶表示パネル１０の表面の異物２１にフォーカス（矢印５１参照）を合わせる場合（ステップＳ１２０）には、カメラ３０のレンズ３０ａの繰り出し量を－０．１０ｍｍとしている。さらに、液晶表示パネル１０の裏面の異物２２にフォーカス（矢印５２参照）を合わせる場合（Ｓ１３０）には、カメラ３０のレンズ３０ａの繰り出し量を＋１．５０ｍｍとしている。すなわち、カメラ３０のレンズ３０ａの繰り出し量の範囲は、液晶表示パネル１０の表面を０ｍｍとした場合には、－０．１０ｍｍ以上であって且つ＋１．５０ｍｍの範囲である。 In the present embodiment, as shown in FIG. 4, when focusing (see arrow 50) on the surface of the liquid crystal display panel 10 (step S110), the extension amount of the lens 30a of the camera 30 is set to 0 mm. Further, when focusing (see arrow 51) on the foreign substance 21 on the surface of the liquid crystal display panel 10 (step S120), the extension amount of the lens 30a of the camera 30 is set to -0.10 mm. Further, when focusing (see arrow 52) on the foreign substance 22 on the back surface of the liquid crystal display panel 10 (S130), the extension amount of the lens 30a of the camera 30 is set to +1.50 mm. That is, the extension range of the lens 30a of the camera 30 is −0.10 mm or more and +1.50 mm when the surface of the liquid crystal display panel 10 is 0 mm.
　なお、ステップＳ１１０におけるフォーカス（５０）は、液晶表示パネル１０の内部の欠陥２０を検出するためのものであるので、フォーカス（５０）は、液晶表示パネル１０の表面（すなわち、ＣＦ基板１１の表面）に限らず、ＣＦ基板１１からＴＦＴ基板１２までの間の範囲で設定することも可能である。言い換えると、液晶表示パネル１０の内部の欠陥２０に対応するコントラスト値（またはコントラスト強度指標値ｔ１）を得るためのものであるので、ＣＦ基板１１、液晶層１５およびＴＦＴ基板１２のいずれかにフォーカスを合わせることができる。 Since the focus (50) in step S110 is for detecting the defect 20 inside the liquid crystal display panel 10, the focus (50) is the surface of the liquid crystal display panel 10 (that is, the surface of the CF substrate 11). However, it is also possible to set in the range from the CF substrate 11 to the TFT substrate 12. In other words, since the contrast value (or contrast intensity index value t1) corresponding to the defect 20 inside the liquid crystal display panel 10 is obtained, the focus is on any of the CF substrate 11, the liquid crystal layer 15, and the TFT substrate 12. Can be combined.
　図５（ａ）から（ｃ）は、本実施形態に係る検査方法を具体的に説明するための概念図である。図５（ａ）から（ｃ）の各図において、右側には、カメラ３０と液晶表示パネル１０との図面を示し、左側にはカメラ３０が撮像した画像データを示す。また、図６（ａ）及び（ｂ）は、それぞれ、本実施形態の検査方法におけるレンズ繰り出し量とコントラスト強度指標値との関係を示す表及びグラフである。また、図７（ａ）及び（ｂ）は、それぞれ、本実施形態の検査方法におけるレンズ繰り出し量とコントラスト強度指標値のピークからの相対値との関係を示す表及びグラフである。 FIGS. 5A to 5C are conceptual diagrams for specifically explaining the inspection method according to the present embodiment. 5A to 5C, the right side shows a drawing of the camera 30 and the liquid crystal display panel 10, and the left side shows image data captured by the camera 30. FIGS. 6A and 6B are a table and a graph showing the relationship between the lens extension amount and the contrast intensity index value in the inspection method of the present embodiment, respectively. 7A and 7B are a table and a graph showing the relationship between the lens extension amount and the relative value from the peak of the contrast intensity index value in the inspection method of the present embodiment, respectively.
　まず、図５（ａ）に示すように、カメラ３０のレンズ３０ａの繰り出し量を０ｍｍとし（基準線３５参照）、液晶表示パネル１０の表面（例えば第１基板１１の上面の高さ位置）にフォーカスポイントＦＰ（５０）を設定して、液晶表示パネル１０を撮像する。この場合、本実施形態では、撮像された画像データ４０には、例えば位置２１Ｐ、２２Ｐ及び２０Ｐにおいて輝点が表示される。そして、画像データ４０に基づいて、コントラスト強度指標値ｔ１を求める。具体的に、本実施形態の例では、図６（ａ）に示すように、０ｍｍのレンズ３０ａの繰り出し量（３５）の場合、コントラスト強度指標値ｔ１は、位置２０Ｐでは３００、位置２１Ｐでは３５０、位置２２Ｐでは２８０である。 First, as shown in FIG. 5A, the extension amount of the lens 30a of the camera 30 is set to 0 mm (see the reference line 35), and the surface of the liquid crystal display panel 10 (for example, the height position of the upper surface of the first substrate 11) is set. The focus point FP (50) is set and the liquid crystal display panel 10 is imaged. In this case, in the present embodiment, bright spots are displayed in the captured image data 40 at, for example, positions 21P, 22P, and 20P. Then, based on the image data 40, a contrast intensity index value t1 is obtained. Specifically, in the example of this embodiment, as shown in FIG. 6A, in the case of the feed amount (35) of the lens 30a of 0 mm, the contrast intensity index value t1 is 300 at the position 20P and 350 at the position 21P. The position 22P is 280.
　次に、図５（ｂ）に示すように、カメラ３０のレンズ３０ａの繰り出し量を－０．１０ｍｍとし（基準線３５ａ参照）、液晶表示パネル１０の表面の異物２１（例えば異物２１の中央高さ位置）にフォーカスポイントＦＰ（５１）を設定して、液晶表示パネル１０を撮像する。すなわち、矢印３６ａに示すように、カメラ３０のレンズ３０ａの繰り出し量を０ｍｍから－０．１０ｍｍへと変更する。 Next, as shown in FIG. 5B, the extension amount of the lens 30a of the camera 30 is set to −0.10 mm (see the reference line 35a), and the foreign matter 21 on the surface of the liquid crystal display panel 10 (for example, the central height of the foreign matter 21). The focus point FP (51) is set at (position), and the liquid crystal display panel 10 is imaged. That is, as shown by the arrow 36a, the extension amount of the lens 30a of the camera 30 is changed from 0 mm to -0.10 mm.
　この場合、本実施形態では、撮像された画像データ４０ａには、例えば位置２１Ｐ、２２Ｐ及び２０Ｐにおいて輝点が表示される。しかしながら、画像データ４０と比較して、位置２２Ｐ及び２０Ｐにおいて、ぼやけた輝点が表示される。具体的に、本実施形態の例では、図６（ａ）に示すように、－０．１０ｍｍのレンズ３０ａの繰り出し量（３５ａ）の場合、コントラスト強度指標値ｔ２は、位置２０Ｐでは２００、位置２１Ｐでは５００、位置２２Ｐでは２７０である。 In this case, in the present embodiment, bright spots are displayed in the captured image data 40a, for example, at positions 21P, 22P, and 20P. However, compared to the image data 40, blurred bright spots are displayed at the positions 22P and 20P. Specifically, in the example of the present embodiment, as shown in FIG. 6A, in the case of the extension amount (35a) of the lens 30a of −0.10 mm, the contrast intensity index value t2 is 200 at the position 20P, the position It is 500 at 21P and 270 at position 22P.
　次に、図５（ｃ）に示すように、カメラ３０のレンズ３０ａの繰り出し量を＋１．５０ｍｍとし（基準線３５ｂ参照）、液晶表示パネル１０の裏面の異物２２（例えば異物２２の中央高さ位置）にフォーカスポイントＦＰ（５２）を設定して、液晶表示パネル１０を撮像する。すなわち、矢印３６ｂに示すように、カメラ３０のレンズ３０ａの繰り出し量を－０．１０ｍｍから＋１．５０ｍｍへと変更する。 Next, as shown in FIG. 5C, the extension amount of the lens 30a of the camera 30 is set to +1.50 mm (see the reference line 35b), and the foreign matter 22 on the back surface of the liquid crystal display panel 10 (for example, the center height of the foreign matter 22). The focus point FP (52) is set at (position), and the liquid crystal display panel 10 is imaged. That is, as shown by the arrow 36b, the extension amount of the lens 30a of the camera 30 is changed from -0.10 mm to +1.50 mm.
　この場合、本実施形態では、撮像された画像データ４０ｂには、例えば位置２１Ｐ、２２Ｐ及び２０Ｐにおいて輝点が表示される。しかしながら、画像データ４０と比較して、位置２１Ｐ及び２０Ｐにおいてはぼやけた輝点が表示される。具体的に、本実施形態の例では、図６（ａ）に示すように、＋１．５０ｍｍのレンズ３０ａの繰り出し量（３５ｂ）の場合、コントラスト強度指標値ｔ３は、位置２０Ｐでは１５０、位置２１Ｐでは２８０、位置２２Ｐでは６００である。 In this case, in the present embodiment, bright spots are displayed in the captured image data 40b, for example, at positions 21P, 22P, and 20P. However, compared to the image data 40, blurred bright spots are displayed at the positions 21P and 20P. Specifically, in the example of this embodiment, as shown in FIG. 6A, in the case of the extension amount (35b) of the lens 30a of +1.50 mm, the contrast intensity index value t3 is 150 at the position 20P and 21P Is 280, and position 22P is 600.
　続いて、得られたコントラスト強度指標値ｔ１、ｔ２、ｔ３について、位置２０Ｐ、２１Ｐ、２２Ｐ毎に対比する。具体的には、位置２０Ｐにおけるコントラスト強度指標値ｔ１、ｔ２、ｔ３については、レンズ３０ａの繰り出し量が０ｍｍの場合（基準線３５）におけるコントラスト強度指標値ｔ１が最も大きい。このため、位置２０Ｐにおけるコントラスト強度指標値は、液晶表示パネル１０の内部の欠陥２０を示しているものと判別する。 Subsequently, the obtained contrast intensity index values t1, t2, and t3 are compared for each of the positions 20P, 21P, and 22P. Specifically, for the contrast intensity index values t1, t2, and t3 at the position 20P, the contrast intensity index value t1 is the largest when the amount of extension of the lens 30a is 0 mm (reference line 35). Therefore, it is determined that the contrast intensity index value at the position 20P indicates the defect 20 inside the liquid crystal display panel 10.
　また、位置２１Ｐにおけるコントラスト強度指標値ｔ１、ｔ２、ｔ３については、レンズ３０ａの繰り出し量が－０．１０ｍｍの場合（基準線３５ａ）おけるコントラスト強度指標値ｔ２が最も大きい。このため、位置２１Ｐにおけるコントラスト強度指標値は、液晶表示パネル１０の表面の異物２１を示しているものと判別する。 Also, with regard to the contrast intensity index values t1, t2, and t3 at the position 21P, the contrast intensity index value t2 is the largest when the amount of extension of the lens 30a is −0.10 mm (reference line 35a). Therefore, it is determined that the contrast intensity index value at the position 21P indicates the foreign matter 21 on the surface of the liquid crystal display panel 10.
　また、位置２２Ｐにおけるコントラスト強度指標値ｔ１、ｔ２、ｔ３については、レンズ３０ａの繰り出し量が＋１．５０ｍｍの場合（基準線３５ｂ）におけるコントラスト強度指標値ｔ３が最も大きい。このため、位置２２Ｐにおけるコントラスト強度指標値は、液晶表示パネル１０の裏面の異物２２を示しているものと判別する。 Also, with respect to the contrast intensity index values t1, t2, and t3 at the position 22P, the contrast intensity index value t3 is the largest when the extension amount of the lens 30a is +1.50 mm (reference line 35b). For this reason, the contrast intensity index value at the position 22P is determined to indicate the foreign matter 22 on the back surface of the liquid crystal display panel 10.
　このようにして、フォーカスポイントＦＰ（またはレンズ３０ａの繰り出し量）と、コントラスト強度指標値ｔ１、ｔ２、ｔ３との対比によって、異物２１、２２と、欠陥２０との判別を簡便に行うことができる。 In this way, the foreign substances 21 and 22 and the defect 20 can be easily distinguished from each other by comparing the focus point FP (or the extension amount of the lens 30a) with the contrast intensity index values t1, t2, and t3. .
　図６（ｂ）は、上述で得られるレンズ繰り出し量（ｍｍ）とコントラスト強度指標値との関係を示したグラフである。図６（ｂ）に示すように、位置２０Ｐ（レンズ繰り出し量が０ｍｍの場合）でピークを有するコントラスト強度指標値の曲線と、位置２１Ｐ（レンズ繰り出し量が－０．１０ｍｍの場合）でピークを有するコントラスト強度指標値の曲線と、位置２２Ｐ（レンズ繰り出し量が＋１．５０ｍｍの場合）でピークを有するコントラスト強度指標値の曲線とが得られる。 FIG. 6B is a graph showing the relationship between the lens extension amount (mm) obtained above and the contrast intensity index value. As shown in FIG. 6B, a contrast intensity index value curve having a peak at a position 20P (when the lens extension amount is 0 mm) and a peak at a position 21P (when the lens extension amount is −0.10 mm). And a contrast intensity index value curve having a peak at the position 22P (when the lens extension amount is +1.50 mm).
　ここで、液晶表示パネル１０の内部の欠陥２０と液晶表示パネル１０の表裏面の異物２１、２２との区別は、より具体的には、コントラスト強度指標値ｔ１、ｔ２、ｔ３のピークからの相対値（％）に基づいて行ってもよい。 Here, the distinction between the defect 20 in the liquid crystal display panel 10 and the foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 is more specifically relative to the peaks of the contrast intensity index values t1, t2, and t3. You may carry out based on a value (%).
　図７（ａ）は、上述した図６（ａ）で表されたコントラスト強度指標値ｔ１、ｔ２、ｔ３について、各位置２０Ｐ、２１Ｐ、２２Ｐ毎に、上述の図６（ｂ）で表された各位置２０Ｐ、２１Ｐ、２２Ｐのピーク値を１００として求めた相対値（％）を示している。図７（ａ）に示すように、位置２０Ｐが液晶表示パネル１０の欠陥２０であり、位置２１Ｐが液晶表示パネル１０の表面の異物２１であり、そして、位置２２Ｐが液晶表示パネル１０の裏面の異物２２であることを判別することができる。 FIG. 7A shows the contrast intensity index values t1, t2, and t3 shown in FIG. 6A described above for each position 20P, 21P, and 22P. The relative values (%) obtained by setting the peak value at each position 20P, 21P, and 22P as 100 are shown. As shown in FIG. 7A, the position 20P is the defect 20 of the liquid crystal display panel 10, the position 21P is the foreign material 21 on the surface of the liquid crystal display panel 10, and the position 22P is on the back surface of the liquid crystal display panel 10. It can be determined that the foreign object 22 is present.
　図７（ｂ）は、レンズ繰り出し量（ｍｍ）とコントラスト強度指標値のピークからの相対値（％）との関係を示したグラフである。図７（ｂ）に示すように、位置２０Ｐ（レンズ繰り出し量が０ｍｍの場合）でピークを有するコントラスト強度指標値のピークからの相対値の曲線と、位置２１Ｐ（レンズ繰り出し量が－０．１０ｍｍの場合）でピークを有するコントラスト強度指標値のピークからの相対値の曲線と、位置２２Ｐ（レンズ繰り出し量が＋１．５０ｍｍの場合）でピークを有するコントラスト強度指標値のピークからの相対値の曲線とが得られる。 FIG. 7B is a graph showing the relationship between the lens feed amount (mm) and the relative value (%) from the peak of the contrast intensity index value. As shown in FIG. 7B, the curve of the relative value from the peak of the contrast intensity index value having a peak at the position 20P (when the lens extension amount is 0 mm) and the position 21P (the lens extension amount is −0.10 mm). Curve of relative intensity from the peak of contrast intensity index value having a peak in FIG. 5 and a curve of relative value from the peak of contrast intensity index value having a peak at position 22P (when the lens extension amount is +1.50 mm). And is obtained.
　上述の図６（ｂ）及び図７（ｂ）の関係から分かるように、カメラ３０のレンズ３０ａのフォーカスポイントＦＰを変化させることで、言い換えると、レンズ３０ａの繰り出し量を変化させることで、コントラスト強度指標値のピークを求めて、そこから、異物２１、２２と欠陥２０とを判別することができる。 As can be seen from the relationship between FIG. 6B and FIG. 7B described above, by changing the focus point FP of the lens 30a of the camera 30, in other words, by changing the extension amount of the lens 30a, the contrast is increased. The peak of the intensity index value is obtained, and the foreign substances 21 and 22 and the defect 20 can be determined therefrom.
　また、本実施形態の構成では、第１基板１１、第２基板１２の厚さ、液晶層１５の厚さ、および、異物２１、２２の寸法を考慮して、フォーカスポイントＦＰまたはレンズ３０ａの繰り出し量の範囲を決定している。すなわち、この例では、液晶表示パネル１０の表面を０ｍｍであるとした場合に、－０．１０ｍｍ以上であって且つ＋１．５０ｍｍの範囲にしているが、これに限定されるものではない。具体的には、実際の条件にあわせて、すなわち、第１基板１１、第２基板１２の厚さ、液晶層１５の厚さ、および、異物２１、２２の寸法を考慮して、フォーカスポイントＦＰまたはレンズ３０ａの繰り出し量の範囲を適宜好適なものを選択することができる。なお、この例では、液晶表示パネル１０の表面の異物２１を検出するためには、レンズ３０ａの繰り出し量は－０．１０ｍｍとすることが望ましく、同様に、液晶表示パネル１０の裏面の異物２２を検出するためには、レンズ３０ａの繰り出し量は＋１．５０ｍｍとすることが望ましい。 In the configuration of the present embodiment, the focus point FP or the lens 30a is extended in consideration of the thicknesses of the first substrate 11 and the second substrate 12, the thickness of the liquid crystal layer 15, and the dimensions of the foreign substances 21 and 22. The amount range is determined. That is, in this example, when the surface of the liquid crystal display panel 10 is 0 mm, the range is −0.10 mm or more and +1.50 mm, but is not limited thereto. Specifically, the focus point FP is adjusted in accordance with actual conditions, that is, in consideration of the thickness of the first substrate 11 and the second substrate 12, the thickness of the liquid crystal layer 15, and the dimensions of the foreign substances 21 and 22. Alternatively, it is possible to select an appropriate range of the extension amount of the lens 30a. In this example, in order to detect the foreign matter 21 on the front surface of the liquid crystal display panel 10, it is desirable that the extension amount of the lens 30a is −0.10 mm. Similarly, the foreign matter 22 on the back surface of the liquid crystal display panel 10 is used. In order to detect this, it is desirable that the extension amount of the lens 30a is +1.50 mm.
　ここで、コントラスト強度指標値とは、カメラ３０によって撮像された画像データに基づいて得られるＣＣＤのコントラスト値であるが、そのコントラスト値は、最大値を利用するだけでなく、積分値を利用することも可能である。すなわち、液晶表示パネル１０の表裏面の異物２１、２２又は内部の欠陥２０が検出される箇所におけるＣＣＤのコントラスト値の積分値を用いることができ、具体的には、画像データ４０に基づいて得られる異物２１、２２又は欠陥２０の周囲のコンストラスト値を含めて（積分して）、それをコントラスト強度指標値とすることができる。これについて図８を参照しながらさらに説明する。 Here, the contrast intensity index value is a CCD contrast value obtained based on image data picked up by the camera 30, and the contrast value uses not only the maximum value but also an integral value. It is also possible. That is, the integrated value of the contrast value of the CCD at the location where the foreign matter 21 or 22 on the front and back surfaces of the liquid crystal display panel 10 or the internal defect 20 is detected can be used. Contrast values around the foreign matter 21 and 22 or the defect 20 to be formed can be included (integrated) and used as a contrast intensity index value. This will be further described with reference to FIG.
　図８は、画素１７が配列されたパターンにおいて、コントラスト値が６０である領域２５ａによって囲まれたコントラスト値が２５０である領域２５ｂとを含む領域２５を示している。この領域２５ｂに、液晶表示パネル１０の表裏面の異物２１、２２又は内部の欠陥２０が存在しているものとする。そして、ここで、コントラスト強度指標値として、図８の例において、各コントラスト値６０及び２５０の値を足し合わせた７３０（６０＋６０＋６０＋６０＋２５０＋６０＋６０＋６０＋６０）というコントラストの積分値（「コンストラスト体積」と称してもよい）を用いると、より人間の目の判断に近づけることができる。すなわち、人間の目による見え方を考えると、一画素の大きな値（２５０）だけの判断よりも、その周囲を含めた値（６０＋６０＋６０＋６０＋２５０＋６０＋６０＋６０＋６０）で評価する方が、良品不良品の判断を現実に即したものに近づけることができる。 FIG. 8 shows a region 25 including a region 25b having a contrast value of 250 surrounded by a region 25a having a contrast value of 60 in the pattern in which the pixels 17 are arranged. It is assumed that foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 or internal defects 20 are present in the region 25b. Here, as the contrast intensity index value, in the example of FIG. 8, the integral value of the contrast of 730 (60 + 60 + 60 + 60 + 250 + 60 + 60 + 60 + 60) obtained by adding the values of the contrast values 60 and 250 (may be referred to as “contrast volume”). Using can make it closer to the judgment of the human eye. In other words, considering the appearance by human eyes, it is more practical to evaluate a non-defective product in reality by evaluating the value including its surroundings (60 + 60 + 60 + 60 + 250 + 60 + 60 + 60 + 60) rather than judging only a large value (250) of one pixel. You can get closer to what you did.
　以上説明したように、本実施形態に係る検査方法では、液晶表示パネル１０の表面（５０）及び液晶表示パネル１０の表裏面（５１、５２）の異物（２１、２２）のそれぞれにフォーカスポイント（ＦＰ）が来るように、カメラ３０のレンズ３０ａの繰り出し量を調節して、液晶表示パネル１０の表面を撮像する。そして、撮像された画像データ４０、４０ａ、４０ｂに基づいて得られたそれぞれのフォーカスポイントにおけるコントラスト強度指標値ｔ１～ｔ３を対比することにより、液晶表示パネル１０の表裏面の異物２１、２２と内部の欠陥２０とを区別することができる。 As described above, in the inspection method according to this embodiment, the focus points (50) on the front surface (50) of the liquid crystal display panel 10 and the foreign matters (21, 22) on the front and back surfaces (51, 52) of the liquid crystal display panel 10 The surface of the liquid crystal display panel 10 is imaged by adjusting the extension amount of the lens 30a of the camera 30 so that FP) comes. The contrast intensity index values t1 to t3 at the respective focus points obtained on the basis of the captured image data 40, 40a, and 40b are compared to thereby compare the foreign substances 21 and 22 on the front and rear surfaces of the liquid crystal display panel 10 with the internal parts. It can be distinguished from the defect 20.
　したがって、本実施形態に係る液晶表示パネルの検査方法によれば、従来のようなゴミ検査用ステージを含む複雑な自動検査装置を用いる必要がなく、液晶表示パネル１０の検査を行う際の工程を簡素化すると共に、液晶表示パネル１０の検査に要する時間を短縮化することができる。特に、従来のようなゴミ検査ステージを設置しなくても、フォーカスポイントを可変可能なカメラ３０を配置するだけで、既存のラインまたは既存のステージで液晶表示パネル１０の検査を実行することができる技術的意義は大きい。 Therefore, according to the method for inspecting the liquid crystal display panel according to the present embodiment, there is no need to use a complicated automatic inspection apparatus including a conventional dust inspection stage, and the process for inspecting the liquid crystal display panel 10 is performed. In addition to simplification, the time required for the inspection of the liquid crystal display panel 10 can be shortened. In particular, the liquid crystal display panel 10 can be inspected on an existing line or on an existing stage simply by disposing a camera 30 with a variable focus point, without installing a conventional dust inspection stage. Technical significance is great.
　なお、上述した第１の実施形態では、例えば図３または図５を用いて、コントラスト強度指標値ｔ１～ｔ３をこの順に求める場合を例に挙げて説明したが、本発明はこの実施形態に限定されるものではない。すなわち、コントラスト強度指標値ｔ１～ｔ３はどのような順序で求めてもよく、いずれの順序を採用した場合であっても、コントラスト強度指標値ｔ１～ｔ３を対比することにより、液晶表示パネル１０の表裏面の異物２１、２２と内部の欠陥２０とを区別することができる。 In the above-described first embodiment, for example, the case where the contrast intensity index values t1 to t3 are obtained in this order has been described with reference to FIG. 3 or FIG. 5, but the present invention is limited to this embodiment. Is not to be done. In other words, the contrast intensity index values t1 to t3 may be obtained in any order. Regardless of which order is adopted, the contrast intensity index values t1 to t3 can be compared to compare the liquid crystal display panel 10. The foreign matters 21 and 22 on the front and back surfaces can be distinguished from the internal defects 20.
＜第２の実施形態＞
　図９（ａ）から（ｃ）は、本発明の第２の実施形態に係る検査方法を説明するための概念図である。図９（ａ）から（ｃ）の各図において、右側には、カメラ３０と液晶表示パネル１０との図面を示し、左側にはカメラ３０が撮像した画像データを示す。 <Second Embodiment>
FIGS. 9A to 9C are conceptual diagrams for explaining an inspection method according to the second embodiment of the present invention. 9A to 9C, the right side shows a drawing of the camera 30 and the liquid crystal display panel 10, and the left side shows image data captured by the camera 30.
　本実施形態に係る検査装置１００の構成は、カメラ（３０、３１、３２）を３台設けている点で、上述した第１の実施形態における検査装置１００の構成と異なっている。ただし、本実施形態に係る検査装置１００のその他の構成は、第１の実施形態に係る検査装置１００の構成と実質的に同様であるので説明を省略する。 The configuration of the inspection apparatus 100 according to the present embodiment is different from the configuration of the inspection apparatus 100 according to the first embodiment described above in that three cameras (30, 31, 32) are provided. However, since the other configuration of the inspection apparatus 100 according to the present embodiment is substantially the same as the configuration of the inspection apparatus 100 according to the first embodiment, the description thereof is omitted.
　本実施形態に係る液晶表示パネルの欠陥検査方法では、３台のカメラ３０、３１、３２のそれぞれのフォーカスポイントを液晶表示パネル１０の表面、液晶表示パネル１０の表面の異物２１、液晶表示パネル１０の裏面の異物２２に合わせて、それぞれのカメラ３０、３１、３２によって液晶表示パネル１０の表面を撮影する。 In the liquid crystal display panel defect inspection method according to the present embodiment, the focus points of the three cameras 30, 31, and 32 are set to the surface of the liquid crystal display panel 10, the foreign material 21 on the surface of the liquid crystal display panel 10, and the liquid crystal display panel 10. The front surface of the liquid crystal display panel 10 is photographed by the respective cameras 30, 31, and 32 in accordance with the foreign matter 22 on the back surface.
　具体的には、図９（ａ）に示すように、カメラ３０は、液晶表示パネル１０の表面にフォーカスを合わせて（レンズ３０ａの繰り出し量が０ｍｍ）、液晶表示パネル１０の表面を撮影し、第１の実施形態と同様の画像データ４０を得る。そして、第１の実施形態での説明と同様に、画像データ４０に基づいて、液晶表示パネル１０の内部の欠陥２０及び液晶表示パネル１０の表裏面の異物２１、２２のいずれかに対応する位置２０Ｐ、２１Ｐ、２２Ｐのコントラスト強度指標値ｔ１を得る。 Specifically, as shown in FIG. 9A, the camera 30 focuses on the surface of the liquid crystal display panel 10 (the amount of extension of the lens 30a is 0 mm) and photographs the surface of the liquid crystal display panel 10. The same image data 40 as in the first embodiment is obtained. Then, similarly to the description in the first embodiment, based on the image data 40, the position corresponding to any of the defect 20 inside the liquid crystal display panel 10 and the foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10. The contrast intensity index values t1 of 20P, 21P, and 22P are obtained.
　また、カメラ３１は、同様に、液晶表示パネル１０の表面に位置する異物２１にフォーカスを合わせて（レンズ３１ａの繰り出し量が－０．１０ｍｍ）、液晶表示パネル１０の表面を撮影し、第１の実施形態と同様の画像データ４０ａを得る。そして、第１の実施形態での説明と同様に、画像データ４０ａに基づいて、液晶表示パネル１０の内部の欠陥２０及び液晶表示パネル１０の表裏面の異物２１、２２のいずれかに対応する位置２０Ｐ、２１Ｐ、２２Ｐのコントラスト強度指標値ｔ２を得る。 Similarly, the camera 31 focuses on the foreign substance 21 positioned on the surface of the liquid crystal display panel 10 (the lens 31a is fed out at −0.10 mm) to photograph the surface of the liquid crystal display panel 10 to obtain the first The same image data 40a as in the embodiment is obtained. Similarly to the description in the first embodiment, based on the image data 40a, the position corresponding to any of the defect 20 inside the liquid crystal display panel 10 and the foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10. The contrast intensity index values t2 of 20P, 21P, and 22P are obtained.
　また、カメラ３２は、同様に、液晶表示パネル１０の裏面に位置する異物２２にフォーカスを合わせて（レンズ３２ａ）の繰り出し量が＋１．５０ｍｍ）、液晶表示パネル１０の裏面を撮影し、第１の実施形態と同様の画像データ４０ｂを得る。そして、第１の実施形態での説明と同様に、画像データ４０ｂに基づいて、液晶表示パネル１０の内部の欠陥２０及び液晶表示パネル１０の表裏面の異物２１、２２のいずれかに対応する位置２０Ｐ、２１Ｐ、２２Ｐのコントラスト強度指標値ｔ３を得る。 Similarly, the camera 32 focuses on the foreign material 22 positioned on the back surface of the liquid crystal display panel 10 (the lens 32a has a feed amount of +1.50 mm) and photographs the back surface of the liquid crystal display panel 10 to obtain the first The same image data 40b as in the embodiment is obtained. Similarly to the description in the first embodiment, based on the image data 40b, the position corresponding to one of the defect 20 inside the liquid crystal display panel 10 and the foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10. The contrast intensity index values t3 of 20P, 21P, and 22P are obtained.
　なお、コントラスト強度指標値ｔ１～ｔ３を得た後は、第１の実施形態での説明と同様の工程を行うことにより、液晶表示パネル１０の表裏面の異物２１、２２と内部の欠陥２０とを区別することができる。 After obtaining the contrast intensity index values t1 to t3, the same processes as described in the first embodiment are performed, so that the foreign substances 21 and 22 on the front and back surfaces of the liquid crystal display panel 10 and the internal defects 20 Can be distinguished.
　以上、第１の実施形態では１台のカメラを用いて３つのフォーカスポイントにレンズ繰り出し量を順次調節して液晶表示パネル１０の表面を撮像し、コントラスト強度指標値ｔ１～ｔ３を得ていたが、本実施形態に係る液晶表示パネルの欠陥検査方法では、それぞれ異なる３つのフォーカスポイントに合わせた３台のカメラを同時に（同一の工程で）用いて液晶表示パネル１０の表面を撮像することができる。このため、本実施形態に係る液晶表示パネルの検査方法は、第１の実施形態と比較して、用いるカメラの台数は増加するものの、液晶表示パネル１０の検査を行う際の工程をより簡素化すると共に、液晶表示パネル１０の検査に要する時間をより短縮化することができる。 As described above, in the first embodiment, a single camera is used to sequentially adjust the lens extension amount to the three focus points to image the surface of the liquid crystal display panel 10 to obtain the contrast intensity index values t1 to t3. In the defect inspection method for the liquid crystal display panel according to the present embodiment, the surface of the liquid crystal display panel 10 can be imaged simultaneously using three cameras that are adjusted to three different focus points (in the same process). . Therefore, the liquid crystal display panel inspection method according to the present embodiment further simplifies the process for inspecting the liquid crystal display panel 10 although the number of cameras to be used is increased as compared to the first embodiment. In addition, the time required for the inspection of the liquid crystal display panel 10 can be further shortened.
　なお、上述の実施形態１及び２では、３つのフォーカスポイントのカメラ３０（または、カメラ３０、３１、３２）によって、第１から第３画像データ４０、４０ａ、４０ｂを得るようにしたが、２つのフォーカスポイントのカメラ３０（または、カメラ３０、３１）によって、異物２１と内部の欠陥２０とを区別することも可能である。具体的には、液晶表示パネル１０の裏面に位置する異物２２は、液晶表示パネル１０の表面まで距離があるために、内部の欠陥２０と区別しやすいことが多い。それゆえに、液晶表示パネル１０の表面に位置する異物２１と、内部の欠陥２０とのコントラスト値（または、コントラスト強度指標値ｔ１、ｔ２）を得ることによって、異物２１と内部の欠陥２０とを区別して、その結果、内部の欠陥２０を特定することが可能となる。また、例えば、図６に示すように、液晶表示パネル１０の裏面に位置する異物２２は、カメラ３０のレンズ３０ａの繰り出し量が０ｍｍである基準線３５のときも、－０．１０ｍｍである基準線３５ａのときも、いずれもコントラスト強度指標値のピークが発生しない。このピークの特性を使うと、２つのフォーカスポイントのカメラ３０（または、カメラ３０、３１）の撮像によって、異物２１と内部の欠陥２０とを区別することが可能となる。加えて、この方式によって、液晶表示パネル１０の裏面に位置する異物２２を特定した場合、液晶表示パネル１０を反転させて、異物２２と内部の欠陥２０とを区別する手法を採ることも可能である。 In the first and second embodiments described above, the first to third image data 40, 40a, and 40b are obtained by the camera 30 (or the cameras 30, 31, and 32) at the three focus points. It is also possible to distinguish between the foreign substance 21 and the internal defect 20 by the camera 30 (or the cameras 30 and 31) at one focus point. Specifically, the foreign matter 22 located on the back surface of the liquid crystal display panel 10 is often easily distinguished from the internal defect 20 because of the distance to the surface of the liquid crystal display panel 10. Therefore, by obtaining the contrast value (or contrast intensity index value t1, t2) between the foreign substance 21 located on the surface of the liquid crystal display panel 10 and the internal defect 20, the foreign substance 21 and the internal defect 20 are separated. Separately, as a result, the internal defect 20 can be specified. Further, for example, as shown in FIG. 6, the foreign material 22 located on the back surface of the liquid crystal display panel 10 is a reference line which is −0.10 mm even when the reference line 35 where the lens 30a of the camera 30 is extended is 0 mm. Even in the case of the line 35a, no peak of the contrast intensity index value occurs. If this peak characteristic is used, it becomes possible to distinguish the foreign substance 21 and the internal defect 20 by imaging with the cameras 30 (or cameras 30, 31) at two focus points. In addition, when the foreign material 22 located on the back surface of the liquid crystal display panel 10 is specified by this method, it is possible to invert the liquid crystal display panel 10 and distinguish the foreign material 22 from the internal defect 20. is there.
　以上、本発明の具体例を、図面を参照しながら説明したが、これらは例示にすぎず、特許請求の範囲を限定するものではない。特許請求の範囲に記載の技術には、以上に例示した具体例を様々に変形、変更したものが含まれる。例えば、上述した実施形態の各要素を相互に適用することも可能である。 As mentioned above, although the specific example of this invention was demonstrated referring drawings, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. For example, the elements of the above-described embodiments can be applied to each other.
　本発明によると、液晶表示パネルの検査を行う際の工程を簡素化すると共に、液晶表示パネルの検査に要する時間を短縮化することができる液晶パネルの検査方法を提供することができる。 According to the present invention, it is possible to provide a liquid crystal panel inspection method capable of simplifying the process for inspecting the liquid crystal display panel and shortening the time required for the inspection of the liquid crystal display panel.
１０   液晶表示パネル
１１   カラーフィルタ基板（第１基板）
１２   アレイ基板（第２基板）
１４   シール材
１５   液晶層
１７   画素
２０   欠陥
２１、２２    異物
３０   カメラ
３０ａ レンズ
４０、４０ａ、４０ｂ　画像データ
１００ 検査装置
１０１ 液晶表示パネル
１０００　検査装置 10 Liquid crystal display panel 11 Color filter substrate (first substrate)
12 Array substrate (second substrate)
14 Sealing material 15 Liquid crystal layer 17 Pixel 20 Defects 21, 22 Foreign matter 30 Camera 30a Lens 40, 40a, 40b Image data 100 Inspection device 101 Liquid crystal display panel 1000 Inspection device

Claims (10)

  1. 　第１基板と、前記第１基板に対向して配置された第２基板と、前記第１基板と前記第２基板との間に設けられた液晶層とを備える液晶表示パネルの検査方法であって、
    　前記液晶パネルにおける前記第1基板、前記液晶層および前記第２基板のいずれかにフォーカスを合わせるようにカメラによって前記液晶表示パネルの第1画像データを撮像し、前記第1の画像データに基づいて、前記第1基板の表面および前記第２基板の裏面に存在し得る異物に対応する位置、および、前記液晶パネルの内部の欠陥に対応する位置における第１コントラスト値を得る工程（ａ）と、
    　前記第１基板の表面に存在し得る異物にフォーカスを合わせるように前記カメラによって前記液晶表示パネルの第２画像データを撮像し、前記第２の画像データに基づいて、前記第1基板の表面および前記第２基板の裏面に存在し得る異物に対応する位置、および、前記液晶パネルの内部の欠陥に対応する位置における第２コントラスト値を得る工程（ｂ）と、
    　前記第２基板の裏面に存在し得る異物にフォーカスを合わせるように前記カメラによって前記液晶表示パネルの第３画像データを撮像し、前記第３画像データに基づいて、前記第1基板の表面および前記第２基板の裏面に存在し得る異物に対応する位置、および、前記液晶パネルの内部の欠陥に対応する位置における第３コントラスト値を得る工程（ｃ）と
    　前記第１から第３コントラスト値を対比することによって、前記異物と前記欠陥とを区別する工程（ｄ）を含む、液晶表示パネルの検査方法。     An inspection method for a liquid crystal display panel, comprising: a first substrate; a second substrate disposed opposite to the first substrate; and a liquid crystal layer provided between the first substrate and the second substrate. And
    First image data of the liquid crystal display panel is picked up by a camera so as to focus on any of the first substrate, the liquid crystal layer, and the second substrate in the liquid crystal panel, and based on the first image data Obtaining a first contrast value at a position corresponding to a foreign substance that may be present on the front surface of the first substrate and the back surface of the second substrate, and a position corresponding to a defect inside the liquid crystal panel;
    The camera captures second image data of the liquid crystal display panel with the camera so as to focus on a foreign substance that may be present on the surface of the first substrate, and based on the second image data, the surface of the first substrate and Obtaining a second contrast value at a position corresponding to a foreign substance that may be present on the back surface of the second substrate and a position corresponding to a defect inside the liquid crystal panel;
    The camera captures third image data of the liquid crystal display panel so as to focus on a foreign substance that may be present on the back surface of the second substrate, and based on the third image data, the front surface of the first substrate and the first substrate Step (c) for obtaining a third contrast value at a position corresponding to a foreign substance that may be present on the back surface of the second substrate and a position corresponding to a defect inside the liquid crystal panel is compared with the first to third contrast values. A method for inspecting a liquid crystal display panel, comprising a step (d) of distinguishing the foreign matter from the defect.
  2. 　前記工程（ａ）から前記工程（ｃ）における前記フォーカスを合わせることは、前記カメラのレンズの繰り出し量を調整することによって実行される、請求項１に記載の液晶表示パネルの検査方法。 2. The method for inspecting a liquid crystal display panel according to claim 1, wherein the focusing from the step (a) to the step (c) is performed by adjusting an extension amount of the lens of the camera.
  3. 　前記カメラは、一台のカメラであり、
    　前記工程（ａ）において、前記フォーカスは、前記第１基板の表面を基準に合わせられる、請求項１または２に記載の液晶表示パネルの検査方法。     The camera is a single camera,
    The liquid crystal display panel inspection method according to claim 1, wherein, in the step (a), the focus is adjusted based on a surface of the first substrate.
  4. 　前記カメラは、三台のカメラであり、
    　前記工程（ａ）から（ｃ）における第１から第３画像データは、それぞれのフォーカスが異なる前記三台のカメラによって同一工程にて撮像される、請求項１または２に記載の液晶表示パネルの検査方法。     The cameras are three cameras,
    3. The liquid crystal display panel according to claim 1, wherein the first to third image data in the steps (a) to (c) are imaged in the same step by the three cameras having different focus. Inspection method.
  5. 　前記第１から第３コントラスト値は、それぞれ、前記第１から第３の画像データにおける前記異物及び前記欠陥に対応する位置のコントラストの積分値を指標にしている、請求項１から４の何れか１つに記載の液晶表示パネルの検査方法。 5. The method according to claim 1, wherein each of the first to third contrast values uses an integral value of a contrast at a position corresponding to the foreign matter and the defect in the first to third image data as an index. The inspection method of the liquid crystal display panel as described in one.
  6. 　前記工程（ｄ）において、前記異物及び前記欠陥のいずれかが存在する第１位置における前記第１から第３コントラスト値を対比することによって、前記第１コントラスト値が最も大きい場合には、前記第１位置には前記欠陥が存在すると判定することを実行する、請求項１から５の何れか１つに記載の液晶表示パネルの検査方法。 In the step (d), by comparing the first to third contrast values at the first position where any of the foreign matter and the defect exists, the first contrast value is the largest. The liquid crystal display panel inspection method according to claim 1, wherein it is determined that the defect exists at one position.
  7. 　前記工程（ｄ）において、前記異物及び前記欠陥のいずれかが存在する第２位置における前記第１から第３コントラスト値を対比することによって、前記第２コントラスト値が最も大きい場合には、前記第２位置には前記異物が存在すると判定し、
    　前記異物及び前記欠陥のいずれかが存在する第３位置における前記第１から第３コントラスト値を対比することによって、前記第３コントラスト値が最も大きい場合には、前記第３位置には前記異物が存在すると判定することを実行する、請求項６に記載の液晶表示パネルの検査方法。     In the step (d), when the second contrast value is the largest by comparing the first to third contrast values at the second position where either the foreign matter or the defect exists, It is determined that the foreign matter is present at position 2,
    When the third contrast value is the largest by comparing the first to third contrast values at the third position where either the foreign matter or the defect exists, the foreign matter is present at the third position. The method for inspecting a liquid crystal display panel according to claim 6, wherein determining that the liquid crystal display panel exists is executed.
  8. 　前記工程（ｄ）においては、前記第１から第３コントラスト値のピークからの相対値を用いて、前記異物と前記欠陥とを区別することを実行する、請求項１から７の何れか１つに記載の液晶表示パネルの検査方法。 In the step (d), discrimination between the foreign matter and the defect is performed using a relative value from the peak of the first to third contrast values. Inspection method of liquid crystal display panel as described in 2.
  9. 　前記カメラは、ＣＣＤカメラ又はＣＭＯＳカメラであり、
    　前記異物は、搬送ローラーの削りカス、洗浄ブラシの削りカス、および、分断機のガラスのカスからなる群から選択される少なくとも一つである、請求項１から８のいずれか１つに記載の液晶表示パネルの検査方法。     The camera is a CCD camera or a CMOS camera,
    9. The foreign object according to claim 1, wherein the foreign matter is at least one selected from the group consisting of a scrap of a transport roller, a scrap of a cleaning brush, and a scrap of glass of a cutting machine. Inspection method for liquid crystal display panels.
  10. 　第１基板と、前記第１基板に対向して配置された第２基板と、前記第１基板と前記第２基板との間に設けられた液晶層とを備える液晶表示パネルの検査方法であって、
    　前記液晶パネルにおける前記第1基板、前記液晶層および前記第２基板のいずれかにフォーカスを合わせるようにカメラによって前記液晶表示パネルの第1画像データを撮像し、前記第1の画像データに基づいて、前記第1基板の表面に存在し得る異物に対応する位置、および、前記液晶パネルの内部の欠陥に対応する位置における第１コントラスト値を得る工程と、
    　前記第１基板の表面に存在し得る異物にフォーカスを合わせるように前記カメラによって前記液晶表示パネルの第２画像データを撮像し、前記第２の画像データに基づいて、前記第1基板の表面に存在し得る異物に対応する位置、および、前記液晶パネルの内部の欠陥に対応する位置における第２コントラスト値を得る工程と
    　前記第１および第２コントラスト値を対比することによって、前記異物と前記欠陥とを区別する工程を含む、液晶表示パネルの検査方法。     An inspection method for a liquid crystal display panel, comprising: a first substrate; a second substrate disposed opposite to the first substrate; and a liquid crystal layer provided between the first substrate and the second substrate. And
    First image data of the liquid crystal display panel is picked up by a camera so as to focus on any of the first substrate, the liquid crystal layer, and the second substrate in the liquid crystal panel, and based on the first image data Obtaining a first contrast value at a position corresponding to a foreign substance that may be present on the surface of the first substrate and a position corresponding to a defect inside the liquid crystal panel;
    The second image data of the liquid crystal display panel is imaged by the camera so as to focus on a foreign substance that may be present on the surface of the first substrate, and on the surface of the first substrate based on the second image data. A step of obtaining a second contrast value at a position corresponding to a foreign substance that may exist and a position corresponding to a defect inside the liquid crystal panel, and comparing the first and second contrast values, thereby the foreign substance and the defect A method for inspecting a liquid crystal display panel, comprising a step of distinguishing between
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