JP2005221291A - Method for inspecting foreign matter in liquid material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for inspecting foreign matter in a liquid material as the quality insurance of the liquid material by a technique automating the inspection of foreign matter and quantitatively enhanced in reliability, and to constitute a rapid and highly reliable evaluation means of mixed foreign matter in the production of the liquid material and the delivery of a product. <P>SOLUTION: In the method for inspecting the foreign matter contained in the liquid material by filtering the liquid material by a filter, the image of the foreign matter captured by the filter after the filtration of the liquid material is photographed by an imaging device and the foreign matter is detected from the image and the size of the foreign matter or the number of the foreign matters is calculated to inspect the foreign matter in paste. The image processable imaging apparatus having an XY stage equipped with a drive mechanism, an irradiation device, a CCD camera, an image processing mechanism and a monitor can be used. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a foreign matter inspection method for liquid matter that contributes to quality assurance of products effectively, by capturing foreign matter mixed in a liquid matter by filtering (filtering), and enabling quick and accurate quantitative evaluation. It is.

  For liquid materials such as water, organic solvents or molten polymers used in the product manufacturing process, it is necessary to inspect the size, number and type of foreign matter mixed in the liquid material to determine the quality status. This is very important for quality control during shipment. A typical example of the liquid material is, for example, a paste for a plasma display panel, and as such a paste, for example, a phosphor produced by kneading, dispersing and filtering a phosphor powder and a polymer liquid. Body paste, dielectric paste produced by kneading, dispersing and filtering a glass powder and a polymer liquid in the same manner, or partition wall paste. When these pastes are applied in a state where granular foreign matters or fibrous foreign matters are present in these pastes, the coating device is clogged, the coating surface is pulled out, the coating film is repelled, and the processed surface is chipped. This causes problems such as stopping the production line and reducing the yield of the panel.

  Conventionally, an inspection method using an in-liquid particle counter (reflection type) is well known in order to detect foreign matter mixed in a transparent liquid material and measure the amount and size of the foreign matter. However, in this inspection method, it is difficult to measure and evaluate a liquid material in which the liquid material is colored or a liquid material including dispersed particles such as an opaque paste.

  Therefore, as a method for inspecting the foreign substance of such a liquid substance, the liquid substance is once filtered through a filter, and a person who visually captures the foreign substance captured on the filter through a microscope or a loupe is counted and counted. It was broken.

  In the conventional inspection method described above, since the entire surface of the filter is observed with a microscope or a loupe while moving the stage in the X and Y axis directions manually, there are problems such as oversight of foreign matter and a lot of time and labor. It was. Furthermore, when quantifying foreign matter supplements on a filter, visual inspection is likely to cause individual differences, and perceptual differences cannot be expressed quantitatively. There was a problem (see Patent Document 1).

In addition, when a highly viscous liquid material is filtered, there is a residual material on the filter, and the foreign material is covered with the residual material, which may make it difficult to observe the foreign material. In such a case, it is necessary to remove the remaining material from the surface of the filter, but in order not to affect the foreign matter to be detected, there is a means for allowing the remaining material to naturally permeate the back of the filter. However, there is a drawback that it takes time and inspection cannot be performed in a short time.
JP 2001-256478 A

  Therefore, the object of the present invention was created to eliminate these various drawbacks, and as a quality assurance of the liquid material, the amount of foreign matter is automatically and quantitatively analyzed in a highly reliable manner. An object of the present invention is to provide a liquid foreign substance inspection method for inspecting foreign substances.

  The object of the present invention is achieved by the following liquid foreign substance inspection method. That is, the foreign matter inspection method for a liquid material according to the present invention is a method for inspecting a foreign material contained in the liquid material by filtering the liquid material with a filter, and is captured by the filter after the liquid material is filtered. This is a liquid foreign matter inspection method characterized in that an image of a foreign matter is taken, the foreign matter is detected from the image, and the size and number of the foreign matter are calculated.

Moreover, the liquid foreign material inspection method of the present invention includes the following preferred embodiments.
(a) Taking an image of a foreign object with an imaging device and identifying a granular foreign object and / or a fibrous foreign object from the image.
(b) The filter is a plain weave lattice fabric.
(c) Detecting foreign matters by applying a smoothing process to erase the image of the filter mesh and make the background uniform.
(d) The liquid remaining on the filter surface after filtering the liquid material is removed by transferring it to an absorbent material that absorbs the liquid material, and an image is taken to detect foreign matter.
(e) The absorbent material that absorbs the remaining liquid is composed of a laminate of metal mesh and metal fiber, an organic fiber structure or a foamed body.
(f) The liquid material contains water, an organic solvent, or a molten polymer.
(g) The liquid material further contains inorganic fine particles and / or organic fine particles.

  The liquid foreign matter inspection method of the present invention is particularly preferably used for foreign matter inspection of an opaque paste for a plasma display panel such as a phosphor paste, a dielectric paste, or a partition paste.

  According to the present invention, foreign matter adhering to a filter obtained by filtering a liquid substance such as liquid or molten polymer is photographed, an image is captured, and from the image, particulate foreign matter or fibrous foreign matter is determined, and the size of the particulate foreign matter and By inspecting the number, the size and the number of fibrous foreign matters, it is possible to cleanly manage tanks and containers used in the product manufacturing process. In addition, by performing foreign matter inspection as part of product quality assurance, it is possible to detect clogging of the coating apparatus and the like, and it is possible to prevent a decrease in productivity due to clogging of liquid materials such as coating agents. In manufacturing liquid products and shipping products, it is possible to quickly and reliably establish a foreign substance evaluation means.

  The liquid foreign matter inspection method of the present invention is a method for inspecting foreign matter contained in a liquid by filtering the liquid through a filter, and the foreign matter captured by the filter after the liquid is filtered. A liquid foreign matter inspection method characterized in that an image is taken, foreign matter is detected from the image, and the size and number of foreign matters are calculated.

  The liquid material used in the present invention is a liquid material such as water, an organic solvent such as ethanol, isopropyl alcohol, normal propyl alcohol and acetone, or a liquid material containing one or more molten polymers. In addition, a polymer, an organic or inorganic additive, and an inorganic or organic powder may be contained.

  Representative examples of such liquid materials include, for example, a phosphor paste made of a phosphor powder and a polymer liquid, a paste for a plasma display panel, such as a dielectric paste made of a glass powder and a polymer liquid, or a partition wall paste. .

  The polymer liquid, which is one component of the paste suitably used in the present invention, is preferably oxidized or / and decomposed or / and vaporized at the time of firing so that no carbide remains in the inorganic substance. , For example, cellulose resins such as ethyl cellulose, methyl cellulose, nitrocellulose, cellulose acetate, cellulose propionate, cellulose butyrate, or methyl (meth) acrylate, ethyl (meth) acrylate, normal butyl (meth) acrylate, isobutyl ( Acrylic resin comprising a polymer or copolymer such as (meth) acrylate, isopropyl (meth) acrylate, 2-ethylmethyl (meth) acrylate, 2-hydroxylethyl (meth) acrylate, poly-α-meth Examples include chilled sulfone, polyvinyl alcohol, and polybutene.

  The content of the polymer (binder resin) in the paste used as a liquid in the present invention is preferably 5 to 65% by weight, more preferably 10 to 60% by weight with respect to 100% by weight of the paste.

In addition, as the phosphor powder in the paste used in the present invention, for example, in red, Y ₂ O ₃ : Eu, YVO ₄ : Eu, (Y, Gd) BO ₃ : Eu, Y ₂ O ₃ S: Eu, γ-Zn ₃ (PO ₄ ) ₂ : Mn, (ZnCd) S: Ag + In ₂ O _{3 and the} like can be mentioned. In green, Zn ₂ GeO ₂ : M, BaAl ₁₂ O ₁₉ : Mn, Zn ₂ SiO ₄ : Mn, LaPO ₄ : Tb, ZnS: Cu, Al, ZnS: Au, Cu, Al, (ZnCd) S: _{Cu, Al, Zn 2 SiO 4} : Mn, As, Y 3 Al 5 O 12: Ce, CeMgAl 11 O 19: Tb, Gd 2 O 2 S: Tb, Y 3 Al 5 O 12: Tb, and ZnO: Zn Etc. In blue, Sr ₅ (PO ₄ ) ₃ Cl: Eu, BaMgAl ₁₄ O ₂₃ : Eu, BaMgAl ₁₆ O ₂₇ : Eu, BaMg ₂ Al ₁₄ O ₂₄ : Eu, ZnS: Ag + red pigment, and Y ₂ SiO ₃ : Ce and the like.

  Moreover, boric acid glass etc. are mentioned as glass powder in the paste used by this invention.

  The content of organic or inorganic additives such as phosphor powder and glass powder, inorganic and organic powders, etc. is preferably 20 to 65% by weight, more preferably 25% with respect to 100% by weight of the paste. ~ 60% by weight.

  Thus, for example, colored inorganic powders, pigments, or organic fine particles such as dyes are used as raw materials in the paste, and the paste becomes an opaque liquid paste. In the present invention, a paste having a transparency of 0% to 10% with a transmittance of 550 nm visible light may be used.

  The liquid material used in the present invention includes a paste composed of the binder resin described above, an organic or inorganic additive, and a mixture of inorganic and organic powder materials. Water etc. may be contained. Examples of the organic solvent include acetone, isopropyl alcohol, isopropylamine, ethanol, gamma butyl lactone, xylene, ethyl acetate, butyl acetate, propyl acetate, terpineol, toluene, normal propyl alcohol, butanol, 2-butanol, and benzyl alcohol. .

  Examples of the paste used as a liquid material in the present invention include, but are not limited to, pastes used for electronic information materials or displays.

  Further, the viscosity of the liquid material used in the present invention is preferably in the range of 1000 mPa · s to 100,000 mPa · s, and the presence or absence of thixotropy is not limited.

  Examples of the foreign matter detected in the present invention include granular foreign matter and fibrous foreign matter. The foreign matter is an external factor generated in the process of producing the mixed liquid material, for example, a foreign matter floating in the atmosphere of the manufacturing equipment room, a dusting foreign matter generated from a line of the manufacturing equipment, or human clothes. The fibrous foreign material etc. are mentioned. Additives and the like that should originally be included as components in the liquid material do not correspond to the foreign substances mentioned here.

  In the present invention, foreign substances contained in the liquid are captured by filtering the liquid with a filter.

  The filter for trapping foreign substances used in the present invention is not particularly limited, but a woven or knitted fabric made of a fibrous material, particularly a filter made of a woven fabric having a plain weave lattice structure is preferably used. As the material of the filter, for example, resins such as polyamide, polypropylene, and fluorine resin, and metals are used. In the case of metals, stainless steel is preferably used because it is less likely to be altered. The filter mesh is selected according to the size of the object to be observed, the size of the dispersed particles in the liquid, and the like, for example, 5 to 100 microns.

  An example of a method for filtering liquid materials is to fill a metal SUS tank with a liquid material, close the lid of the metal SUS tank and seal it, and insert a nylon tube or a fluorine-based tube to extract the liquid material into the tank. A filter (holder) is attached to one side of the tube, air is pressurized and carried into the tank at a pressure of 0.18 MPa, and the liquid is extracted and filtered.

  Although the trapped foreign matter and the residual liquid (remaining material) are mixed and left on the filtered filter surface, the residual liquid can be removed from the filter because the foreign matter on the filter is extracted. In order to remove the residual liquid from the filter, a material that transfers the residual liquid to the back surface of the filter, for example, an absorbent material that absorbs the residual liquid is adhered to the back surface or / and the surface of the filter to absorb and remove the residual liquid. it can. Alternatively, the residual liquid can be transferred to an absorbing material to remove the residual liquid from the filter, and foreign matter can be extracted and detected.

  Examples of the absorbent material for removing the residual liquid in this way include a laminate of metal mesh and metal fiber, an organic fiber structure such as a woven or non-woven fabric made of organic fibers, or a foamed body. Alternatively, a combination of these can be used. In particular, since there is an advantage that the shape of the filter that captures the foreign matter can be retained on a flat surface and can be reused by washing, the metal mesh (preferably # 20 to # 50) and the metal fiber sintered body are used. It is preferable to use a laminate. Thereby, the transfer effect of the remaining liquid can be remarkably increased, measurement evaluation can be performed quickly, and the foreign matter detection accuracy can be improved.

  In the present invention, since the trapped foreign matter remains on the filter after the liquid material is filtered, the foreign matter is detected and identified. In the present invention, an automatic foreign matter inspection device, for example, an automatic foreign matter inspection device (DTM-101) manufactured by Disctec Co., Ltd. can be used as the imaging device for this purpose.

  Next, the principle of detection and identification of foreign matters captured on the filter will be described. A video camera scope (for example, 1/2 CCD, viewing angle 3.2 mm × 2.4 mm, pixel size 5 microns / 1 pixel) is scanned over the entire surface of the filter to capture an image. The image can be analyzed by morphological processing. Morphological processing is a technique based on set operations. An image is expressed as a set, and is defined by a set operation between an image to be processed and an image of a structural element that is a basic unit of processing. This technique is generally effective for detecting a subtle shadow of an image. The original image is subjected to image processing. In the processing, the vertical mesh and horizontal mesh, which are the mesh portions of the filter, are sequentially erased and averaged to make the background uniform. The color-coded portion obtained by executing the two operations can be recognized by image processing and detected as an extracted foreign matter portion. For the detected foreign matter, the size of each foreign matter portion is calculated and calculated as an area as a final process. In addition, regarding the foreign matter, the distinction between the granular foreign matter and the fibrous foreign matter is determined by the ratio of the shape XY.

  The effectiveness of discriminating between the granular foreign matter and the fiber foreign matter can be specified from the foreign matter library and the characteristic factor diagram created in advance when the occurrence location of the foreign matter mixed in the liquid material is examined. From the image data of the image inspection machine, for example, it is classified into granular foreign matters and fibrous foreign matters, and the composition is analyzed by an analysis method (organic analysis / inorganic analysis). It can be identified, and it is possible to suppress the generation of foreign matter by implementing clean measures and dust generation measures at the occurrence location.

  Thus, when the foreign substance inspection of the fluid is performed using the liquid foreign substance inspection method of the present invention, the foreign substance can be inspected with high accuracy in a short time. If it is taken in as a product shipment inspection of the paste, the facility trouble due to the foreign matter can be prevented in advance for the customer by stopping the shipment when the foreign matter exceeds the specified amount. The prescribed amount of foreign matter is preferably 20 or less for granular foreign matter and 10 or less for fibrous foreign matter. In addition, foreign matter data can be fed back to reduce the amount of foreign matter from the place where the foreign matter is generated and supply a stable paste.

  By the liquid foreign substance inspection method of the present invention, the quantitative evaluation of foreign substances in liquids and fluids can be quickly realized, and the quality control aspect of the shipping inspection can be performed by quantifying the foreign substances in the paste. In addition, manufacturing process management can be efficiently realized by using liquid foreign matter data in order to stably supply a certain quality.

  The liquid foreign substance inspection method of the present invention will be specifically described below with reference to the drawings. In the present embodiment, a method applied to inspection of foreign matters mixed in a liquid manufacturing process will be described.

  FIG. 1 shows a work sample of the present invention, and is a schematic cross-sectional view for explaining a state in which the liquid remaining on the filter surface moves through the filter. In FIG. 1, after the liquid material is filtered, the residue of the liquid material, that is, the foreign material (not shown) and the remaining liquid A are left on the filter B for capturing the foreign material. The foreign matter catching filter B is a metal mesh SUS # 500 plain weave lattice structure. The residual liquid A is absorbed by natural suction by the absorbent material C laminated on the lower part (back surface) of the filter B, and only the foreign matter remains on the filter B. As the absorbent material C, as described above, a laminate having a two-layer structure of a metal mesh and a metal fiber sintered body can be used.

  FIG. 2 is a schematic block diagram for illustrating the automatic inspection apparatus used in the present invention. In the automatic inspection apparatus of FIG. 2, an illuminating device 3, a CCD camera 4, and an objective lens 5 are installed on a support base 2 on a fixed base 1 so as to be able to move up and down in order in a straight line. The illuminating device 3, the CCD camera 4, and the objective lens 5 are configured to be fixed at arbitrary positions.

A work sample 6 is manually set at the center of the XY stage 7 immediately below the objective lens 5.
Initialization is set from the personal computer 11, here, the size of the work sample 6 and the measurement range of the work sample 6 are set. The focal lengths of the objective lens 5 and the work sample 6 are manually adjusted. Next, a signal from the axis control board 13 of the personal computer 11 is transmitted to the motor driver 10, and the XY stage 7 is driven and controlled so as to move all around in two directions, the X axis direction and the Y axis direction. In conjunction with the circumferential movement, the surface of the work sample 6 is irradiated with light of different wavelengths, and images taken from the objective lens 5 and the CCD camera 4 by the image processing board 12 are sequentially stored for each coordinate axis. Image processing is performed by the keyboard 9 and the CRT 8.

  FIG. 3 is a plan view showing foreign object detection and image processing results. As shown in FIG. 3, the morphology process is executed on the stored image for each coordinate axis. First, in FIG. 3A, in order to identify the filter mesh and foreign matter, the background of the filter vertical portion and the filter horizontal portion, which are the filter mesh, is sequentially deleted by open (OPEN) processing, as shown in FIG. 3B. Perform smoothing. Next, as shown in FIG. 3C, granular foreign matters and fibrous foreign matters are identified by a blob process. From these processes, an arithmetic process is executed, and the number and size are counted and stored in the personal computer 11 as data.

  Next, the liquid foreign substance inspection method of the present invention will be described in Examples.

(Example 1)
A phosphor paste for a plasma display panel was used as the liquid material. The phosphor paste for plasma display panel was prepared by kneading a binder resin and phosphor powder. Ethyl cellulose was used as a binder resin, and a red composition Y ₂ O ₃ : Eu was used as a phosphor powder raw material. The contents of the binder resin and the phosphor powder were 50% by weight, respectively. The viscosity of the obtained phosphor paste was 50000 mPa · s. Next, after filling the product container with a predetermined amount of the phosphor paste, 0.18 MPa air pressure was applied to the product container, and 500 g of the phosphor paste was filtered with a SUS316 # 500 filter (φ47 mm) while extracting the phosphor paste. Then, the SUS316 # 500 filter used for filtration was placed on the laminate of the metal mesh and the metal fiber sintered body, and the remaining paste was transferred to the back surface of the filter. The workpiece sample filter obtained after 20 minutes was subjected to detection and measurement of foreign matters with the foreign matter inspection apparatus having the above-described configuration. The measurement time was 5 minutes, and 10 fibrous foreign matters and 30 granular foreign matters were detected. The size of the fibrous foreign material was about 5 μm to about 10 μm in thickness and about 800 μm to about 1000 μm in length, and the type was natural fiber. Moreover, the size of the granular foreign material was about 40 μm × about 60 μm, and the type was metal SUS powder.

(Example 2)
Using the same phosphor paste manufacturing method and binder resin as in Example 1, the phosphor paste was changed to a blue powder and the inspection was conducted. The blue powder composition was Sr ₅ (PO ₄ ) ₃ Cl: Eu, and the content was 50% by weight of binder resin and 50% by weight of blue powder. The viscosity was 30000 mPa · s. When the same filtration method and filter sample as in Example 1 were prepared and foreign matter was evaluated using the same inspection apparatus, 12 fibrous foreign matters and 26 granular foreign matters were detected in 5 minutes. The size of the fibrous foreign matter was about 5 μm to about 10 μm in thickness and about 800 μm to about 1000 μm in length as in Example 1, and the type was natural fiber. Moreover, the size of the granular foreign material was about 50 μm × about 70 μm, and the type was metal SUS powder as in Example 1.

(Example 3)
In Example 2, the inspection was performed in the same manner as in Example 2 except that the green powder changed to the blue powder was used as the phosphor powder. The green powder composition used Zn ₂ GeO ₂ : M and had a binder resin content of 50% by weight and a green powder content of 50% by weight. The viscosity was 25000 mPa · s. When the same filtration method and filter sampling as in Example 2 were prepared and foreign matter was evaluated using the same inspection apparatus, nine fibrous foreign matters and 24 granular foreign matters were detected in a measurement time of 5 minutes. The size of the fibrous foreign matter was about 5 μm to about 10 μm in thickness and about 800 μm to about 1000 μm in length as in Example 1, and the type was natural fiber. Moreover, the size of the granular foreign matter was about 55 μm × about 90 μm, and the type was metal SUS powder as in Example 1.

Example 4
A foreign substance adhering to the inner surface of a stainless steel delivery tank (made of 30L stainless steel) whose inner surface was coated with a ceramic paste using a phosphor paste was inspected. After the inside of the delivery tank was washed, the inner surface of the delivery tank was rinsed with a test liquid (ethanol 500 ml), and the liquid was collected in a clean bottle. The collected liquid was naturally filtered in a clean bench using a nylon mesh # 10φ47 mm filter. Thereafter, the filtered filter was placed on a laminate of a metal mesh (φ47) and a metal fiber sintered body (φ47 mm), and ethanol as a residual liquid was transferred to the back surface of the filter. The obtained work sample filter was measured in the same manner as in Example 1. Two fibrous foreign matters and five granular foreign matters were detected. The size of the fibrous foreign matter was about 5 μm to about 10 μm in thickness and about 800 μm to about 1000 μm in length as in Example 1, and the type was natural fiber. Moreover, the size of the granular foreign matter was about 55 μm × about 90 μm, and the type was metal SUS powder as in Example 1.

(Example 5)
As a liquid material, a phosphor paste for a plasma display panel was used as in Example 1. The phosphor paste was prepared by kneading a binder resin and phosphor powder. Ethyl cellulose was used as a binder resin. The composition Y ₂ O ₃ : Eu was used for the red color of the phosphor powder material. The contents of the binder resin and the phosphor powder were 50% by weight, respectively. The viscosity of the obtained phosphor paste was 49000 mPa · s. Next, the blue color of the phosphor powder material was Sr ₅ (PO ₄ ) ₃ Cl: Eu, and the content was 50% by weight of binder resin and 50% by weight of blue powder. The viscosity was 29500 mPa · s. Next, the green composition Zn ₂ GeO ₂ : M of the phosphor powder raw material was used, and the content of the binder resin was 50% by weight and the green powder was 50% by weight. The viscosity was 25000 mPa · s. Next, each color phosphor paste is filled with a specified amount of phosphor paste in a product container designated for each color in the same manner as in Example 1, and then air pressure is applied to the product container at 0.18 MPa to extract SUS316 # while extracting the phosphor paste. 500 g of the phosphor paste was filtered with a 500 filter (φ47 mm). The remaining paste is transferred in order to inspect the foreign matter on the filter obtained by filtration. As a means for shifting, the filters of each color were left on the petri dish at the same time. By leaving it for 3 hours, the paste remaining on the filter almost moved to the back surface, and it became measurable, and it took 3 hours to prepare for the measurement. Measurement was performed with a foreign matter inspection apparatus having the same configuration as that of the first embodiment. The measurement time is 5 minutes, and the number and type of the obtained granular foreign matters and fibrous foreign matters are as in Example 1 for phosphor red, Example 2 for phosphor blue, and Example 3 for phosphor green. Similar results were obtained.
(Comparative Example 1)
While observing the entire surface of the work sample filter obtained in the same manner as in Example 1 with a microscope (× 200), the XY stage was moved by hand and observed. The measurement time was 6 times that of Example 1 and required 30 minutes. Further, the number of foreign matters confirmed was 7 fibrous foreign matters and 24 granular foreign matters, which were overlooked compared to Example 1.

(Comparative Example 2)
The evaluation filter obtained in the same manner as in Example 2 was confirmed by the same means as in Comparative Example 1. As a result, the measurement time was 35 minutes. In addition, the number of foreign matters was 8 fibrous foreign matters and 24 granular foreign matters, which were overlooked compared to Example 2.

(Comparative Example 3)
The evaluation filter obtained in the same manner as in Example 3 was confirmed by the same means as in Comparative Example 1. As a result, the measurement time was 33 minutes. In addition, the number of foreign matters was 8 fibrous foreign matters and 20 granular foreign matters, which were overlooked compared to Example 3.
(Comparative Example 4)
3 g of the same phosphor paste as used in Example 1 was dropped on a glass substrate having a size of 12.5 × 12.5 cm and a thickness of 1.2 t, and about 20-30 μm was applied with an applicator. Although foreign matter was visually inspected, it was difficult to detect fibrous foreign matter and granular foreign matter.

  The liquid foreign matter inspection method of the present invention is particularly preferably used for foreign matter inspection of a paste for a plasma display panel such as a phosphor paste, a dielectric paste, or a partition paste. According to the present invention, a foreign matter adhering to a filter obtained by filtering a liquid substance such as a liquid is photographed, an image is captured, and a granular foreign matter or a fibrous foreign matter is determined from the image. By inspecting the size and number of foreign substances, it is possible to cleanly manage tanks and containers used in the product manufacturing process. In addition, inspection of foreign matter as part of product quality assurance can detect clogging of the coating apparatus and is useful in preventing a decrease in productivity due to the influence of clogging.

FIG. 1 is a schematic cross-sectional view for explaining a state in which the liquid remaining on the filter surface moves through the filter. FIG. 2 is a schematic block diagram for illustrating the automatic inspection apparatus used in the present invention. FIG. 3 is a plan view showing foreign object detection and image processing results.

Explanation of symbols

A Residual liquid B Filter C Absorbent 1 Fixed base 2 Support base 3 Illumination device 4 CCD camera 5 Objective lens 6 Work sample 7 XY stage 8 CRT
9 Keyboard 10 Motor driver 11 Personal computer 12 Image processing board 13 Axis control board

Claims (8)

  A method of inspecting foreign matter contained in the liquid material by filtering the liquid material with a filter, wherein an image of the foreign material captured by the filter after the liquid material is filtered is taken, and the foreign material is removed from the image. A liquid foreign matter inspection method, characterized by detecting and calculating the size and number of foreign matters.   The liquid foreign substance inspection method according to claim 1, wherein an image of the foreign substance is picked up by an imaging device, and particulate foreign substances and / or fibrous foreign substances are identified from the image.   2. The liquid foreign matter inspection method according to claim 1, wherein the filter is a woven fabric having a plain weave lattice structure.   2. The liquid foreign matter inspection method according to claim 1, wherein the foreign matter is detected by performing a smoothing process to erase the image of the mesh portion of the filter and make the background uniform.   2. The foreign matter inspection of a liquid material according to claim 1, wherein the liquid remaining on the filter surface after filtering the liquid material is removed by transferring it to an absorbent material that absorbs the residual liquid, and an image is taken to detect the foreign matter. Method.   6. The liquid foreign substance inspection method according to claim 5, wherein the absorbent that absorbs the remaining liquid is composed of a laminate of metal mesh and metal fiber, an organic fiber structure, or a foam.   The liquid foreign material inspection method according to claim 1, wherein the liquid material contains water, an organic solvent, or a molten polymer.   8. The liquid foreign substance inspection method according to claim 7, wherein the liquid further contains inorganic fine particles and / or organic fine particles.