Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T7/00—Image analysis
  • G06T7/0002—Inspection of images, e.g. flaw detection
  • G06T7/0004—Industrial image inspection
  • G06T7/0008—Industrial image inspection checking presence/absence
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
  • G01N21/892—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles characterised by the flaw, defect or object feature examined
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T2207/00—Indexing scheme for image analysis or image enhancement
  • G06T2207/30—Subject of image; Context of image processing
  • G06T2207/30108—Industrial image inspection
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T2207/00—Indexing scheme for image analysis or image enhancement
  • G06T2207/30—Subject of image; Context of image processing
  • G06T2207/30204—Marker

Definitions

• the present invention relates to a method for detecting a mark applied to a resin film. Specifically, the present invention relates to a method of detecting a mark provided to indicate a defect position of a resin film such as an optical film.
• a resin film such as an optical film is usually manufactured in a long strip shape with a constant width, subjected to various treatments in that state, wound on a roll, and stored as a raw film.
• a sheet-shaped film having a predetermined shape is cut out from the raw film according to the product specifications (see, for example, Japanese Patent Laid-Open No. 2000-0130 070).
• the defect detection of the resin film is usually performed in a belt-like state, and a mark is given by a felt pen or an ink jet so that the defect part can be easily identified. If there is a defect in the cut sheet film, even if it is difficult to identify with the naked eye, a mark is given and it can be easily identified and easily removed from the product.
• the mark applied to the resin film is automatically detected with high accuracy. A method is desired.
• JP-A-6-5 a method for determining the color and size of a mark from three types of images obtained by binarizing R, G, and B signals from a color camera is known (JP-A-6-5). (See 0 7 3 5).
• An object of the present invention is to provide a method for accurately detecting marks provided on a resin film in order to indicate a defect position or the like.
• the present inventors irradiate light to a resin film provided with a color mark except for a black color system.
• the transmitted image or reflected image is captured with a color CCD power camera, and the RGB signal obtained from the color CCD camera is processed with the HSV color system, and the resulting hue (H), saturation (S), and brightness (
• the range of V) is expressed in 256 gradations, the range is set according to the color of the mark assigned by hue (H), the saturation (S) is in the range of 100 to 225, and the brightness (V) It was found that by detecting the mark based on the number of pixels satisfying the range of 220 to 255, it was possible to detect the assigned mark with high accuracy, and the present invention was achieved. Disclosure of the invention
• the present invention is a method for detecting a mark imparted to a resin film with a color other than black, and irradiates the resin film with the mark with light, and transmits the transmitted image or reflected image as a color CCD.
• the image is captured by the camera, the RGB signal from the color CCD camera is processed in the HSV color system, and the resulting hue (H), saturation (S), and brightness (V) ranges are each expressed in 256 tones. Range set according to the color of the mark assigned by hue (H), saturation (S) in the range of 100 to 225, and brightness (V)
• the hue (H) range expressed in 256 gradations is 0 to 20 or 235 to 255 for red marks, 135 to 175 for blue marks, and 135 to 175 for green marks. This is a method for detecting the marks 75 to 115.
• the detection of the mark that is determined to be a mark provided when the area corresponding to the mark obtained from a pixel that satisfies the range is 70% or more of the set area.
• FIG. 1 is a schematic view showing an example of an apparatus used in the present invention. Explanation of symbols
• the resin film examples include, but are not limited to, optical films such as polarizing films, retardation films, and optical compensation films, polyolefin films, acrylic films, and polysulfone films.
• a mark imparted to the resin film with a color other than black is detected.
• the marking method is performed by a publicly known method, and is usually performed manually using a felt-tip pen, an ink jet or the like, or automatically by a method described in, for example, Japanese Patent Laid-Open No. 2 0 1-3 0 5 0 70 Done.
• Black and gray black marks are removable deposits other than the detection target mark. Since they are sometimes detected, they are given marks of colors other than black, such as red, blue, and green, which are difficult to detect. If the resin film has a color pattern, a mark different from the pattern color is given.
• the shape of the mark is not particularly limited, but usually a linear mark is given.
• the applied mark is imaged by irradiating the resin film with light and capturing the transmitted or reflected image with a power CCD camera.
• Examples of light include visible light and ultraviolet light. If the mark is applied with a highlighter, irradiate with ultraviolet light.
• a white lamp, a fluorescent lamp, an ultraviolet lamp, etc. are used as the light source.
• the black and white camera may not be able to detect the mark depending on the color of the mark, in the present invention, a mark other than the black system is added and the image is taken with the color CCD camera.
• the resin film is transparent, the transmission image or reflection image is captured with a color CCD, and when it is opaque, the reflection image is captured.
• RGB signal from a color CCD camera is processed with the HSV color system using an image processor, and the hue (H), saturation (S), and lightness (V) ranges of the pixels satisfy the set range.
• a mark is detected based on the pixel to be processed.
• Image processing can be performed using a commercially available device.
• the hue (H) range is set according to the color of the assigned mark.
• the range is expressed in 256 gradations (the same applies hereinafter). For example, in the case of a red mark, 0 to 20 or 235 to 255, preferably 0 to 9 or 250 to 255, in the case of a blue mark Is 135 to 175, preferably 141 to 169, and in the case of a green mark, is 75 to 1 15, preferably 80 to 108. Pixels that do not satisfy these ranges are not pixels that make up the color mark to be detected.
• the saturation (S) range is 100 to 225, preferably 105 to 220, regardless of the mark color
• the brightness (V) range is 220 to 255, preferably 245, regardless of the mark color. ⁇ 255. If you narrow these ranges, Detection of a rubbed mark is insufficient.
• the area corresponding to the mark is obtained from the pixels satisfying the above range. Since the size of one pixel is known in advance, the area is obtained from the number of pixels. Usually, the area of the assigned mark or the area of the mark portion to be photographed is known in advance, and this area is set as the set area.
• the mark is provided when the area obtained from the pixel is 70% or more, preferably 80% or more of the set area. Although it is possible to determine by determining the shape of the mark from the pixel, a method for determining the area is easy and preferable.
• FIG. 1 is a schematic diagram showing an example of an apparatus used in the present invention.
• the defect detection device and marking device not shown in the preceding figure detect defects in the resin film, mark the resin film with a color other than black to indicate the position of the defect, wind it up on a roll, and store it. ing.
• the cut sheet 4 is transported to the sorting device 8 by the transport conveyors 5 and 6 and the support roll 7.
• RGB signal obtained from a color CCD camera is processed with the HSV color system using the image processor 1 1, and the range of hue (H), saturation (S) and lightness (V) of the resulting pixel is marked with a red mark.
• each is expressed in 2 5 6 tones, and the hue (H) ranges from 0 to 20 or 2 3 5 to 2 5 5 and the saturation (S) ranges from 1 0 0 to 2 2 5
• the mark is detected based on a pixel whose range and brightness (V) satisfy the range of 220 to 25.sub.5. If the area corresponding to the mark obtained from a pixel that satisfies the above range is 70% or more of the set area, it is determined that the mark is given.
• the processing data is stored in the control device 12 and displayed on the recorder 13 if necessary.
• a sheet film that is determined to have a mark is a sheet film that is not marked in the sorting device 8 based on the conveyance speed of the resin film from the conveyance speed detection means (not shown). And sort. Examples of the present invention will be described below, but the present invention is not limited to these. Example 1
• White light (light source: fluorescent lamp surface light source, manufactured by Cabin Co., Ltd.) is irradiated from the bottom of this film, and the transmitted image is viewed from above.
• the image was taken with a color CCD camera (2 million strokes) and the RGB signal was processed with the HSV color system. It should be noted that only the tip of the mark (length 2.5mm) was taken.
• the hue (H) setting range expressed in 256 gradations is 0 to 20 or 235 to 255
• the saturation (S) setting range is 100 to 225
• the lightness (V) setting range is
• the set area corresponding to the mark to be photographed was 5 mm 2 (width 2111111 length 2.5111 m).
• the hue (H) range of the obtained pixels is 254 to 255
• the saturation (S) range is 173 to 213
• the lightness (V) range is 225 to 255, each satisfying the setting range. there were.
• the area corresponding to the mark was calculated from the area (0.052 mm 2 ) of the pixel that satisfies this setting range and the number of pixels, and it was 4 mm 2 , which was 80% of the set area 5 mm 2 .
• the hue (H) setting range was 253 to 254
• the area obtained from pixels satisfying this range was less than 70% of the setting area, and the assigned mark could not be detected.
• the saturation (S) setting range was 153 to 193, the assigned mark could not be detected.
• Example 1 The red felt pen used in Example 1 was consumed to give a thin, linear mark (length: about 23 mm, width: about 2 mm, area: about 69 mm 2 ), Marks were detected in the same manner as in Example 1.
• the range of hue (H) of the obtained pixel is 2 5 4, the range of saturation (S) is 1 7 4 to 1 9 7, and the range of lightness (V) is 2 3 4 to 2 4 9 Yes, each satisfied the set range. Area of the pixel that satisfies the specified range of this (0. 0 5 2 mm 2 ) with a 4 mm 2 was determined and the area corresponding to the mark from that number was 80% of the set area 5 mm 2 . If the saturation (S) setting range is 1 5 4 to 1 7 7, the area obtained from pixels that satisfy this range is less than 70% of the setting area, and the assigned mark can be detected. There wasn't. In addition, when the brightness (V) setting range was 2 14 to 2 29, it was not possible to detect the assigned marks. According to the present invention, it is possible to accurately detect a mark given to a resin film even when the mark is thin or faint.

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• Engineering & Computer Science (AREA)
• Quality & Reliability (AREA)
• Computer Vision & Pattern Recognition (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
• Image Processing (AREA)
• Image Analysis (AREA)

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Citations (3)

• 2006
  • 2006-12-12 JP JP2006334105A patent/JP2008146432A/ja active Pending
• 2007
  • 2007-12-06 WO PCT/JP2007/073982 patent/WO2008072679A1/ja active Application Filing
  • 2007-12-10 TW TW96147044A patent/TW200839222A/zh unknown

Patent Citations (3)

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