JP2008107132A - Foreign matter inspection method and foreign matter inspection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foreign matter inspection system for accurately inspecting fine foreign matters present on the surface of an inspection target by one foreign matter inspection operation, even if the inspection target is transparent or opaque, and a foreign matter inspection method. <P>SOLUTION: In the foreign matter inspection method for inspecting the foreign matter on the surface of the sheet-like inspection target supported by a support member to be continuously fed by using the foreign matter inspection system, having an inspection light irradiation part, a light detecting part, and an imaging processing part, inspection light is emitted in the tangential direction of the support member and the sheet-like inspection target at an angle of 80-90°, with respect to the normal line at the contact point of the support member and the sheet-like inspection target. The scattered light of the inspection light scattered by irradiating the foreign matter is detected by the light detection part, and the data of the light detection part is analyzed by the imaging processing part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a surface inspection method and a foreign matter inspection apparatus for detecting foreign matter existing on the surface of a sheet-like object to be inspected.

  Conventionally, in various manufacturing industries that handle sheet-like materials (for example, resin films, paper, metal plates, etc.), surface defects on products that use materials and materials that are used in terms of product quality improvement and stability, Inspections are performed for defects that may affect the performance of the product, such as adhered foreign matter and flatness.

  For example, recently, the demand for liquid crystal display devices (LCD) and organic EL elements using organic substances has increased due to the widespread use of liquid crystal displays mounted on automobiles, large liquid crystal television displays, mobile phones, notebook personal computers, and the like. LCDs are widely used as monitors because they save space and energy compared to conventional CRT display devices. Furthermore, it is also spreading for TV. In addition, organic EL devices are widely used as solid light emitting type inexpensive large-area full-color display devices and writing light source arrays.

  In such a liquid crystal display device, resin films are used as various optical films such as a polarizing plate protective film, an optical compensation film, an antiglare film, a polarizing film and a retardation film. For example, the polarizing plate has a configuration in which an optical film is bonded to both sides of a polarizer. The polarizing plate plays an important role of allowing only light of a polarization plane in a certain direction to pass through and visualizing changes in the alignment of the liquid crystal due to an electric field. When this optical film is used with foreign matter attached, the polarization direction of light passing therethrough is not constant, and there is a risk that the performance of the liquid crystal display device will be greatly affected. It is used after confirming that.

  The organic EL element includes a first electrode (anode or cathode) formed on a substrate and an organic compound layer (single layer portion or multilayer portion) containing an organic light emitting material stacked thereon, that is, a light emitting layer. A thin film type device having a second electrode (cathode or anode) laminated on the light emitting layer. When a voltage is applied to such an organic EL element, electrons are injected from the cathode and holes are injected from the anode into the organic compound layer. It is known that light is obtained by releasing energy as light when the electrons and holes recombine in the light emitting layer and the energy level returns from the conduction band to the valence band. When the organic EL element is used, it is used in a state of being sealed by a sealing member using a metal or metal foil in order to prevent moisture from being transmitted and extend the life. If the surface of the sealing member used for these is used with foreign matter attached, the moisture-proof effect at the part where the foreign matter is attached will be reduced, and the life of the organic EL element will be shortened. It is used after confirming that there is no.

  Examples of the paper material include photo print paper from a digital camera, various print papers, and the like. Usually, in order to obtain a high-quality print, photographic print paper is variously processed by coating on the surface of a paper support. When the surface is processed with foreign matter attached to the surface of the paper support, the surface property is not stabilized by the foreign matter, resulting in a product with poor product performance. In addition, when used in a state where foreign matter adheres during processing, there is a risk of becoming a defective product depending on what is printed. For this reason, it is used after carrying out sufficient defect inspection on the paper support and product to be used and confirming that there is no defect.

  Thus, examination of the inspection method of the foreign material which exists in the surface of the support body, material, and product to be used has been carried out until now in each field. For example, a phase serving mirror is used as an optical reflecting means, and the inspection light irradiated to the foreign object on the object to be inspected is reflected and irradiated again on the foreign object on the object to be inspected twice. Therefore, since the amount of light from the foreign matter is almost doubled, a method for stably detecting defects such as fine foreign matter on the order of submicron with a high S / N ratio (Signal to Noise ratio) is known. (See Patent Document 1).

  However, the method described in Patent Document 1 irradiates the inspection object with the inspection light. In addition to the scattered light from the foreign matter adhering to the inspection object, the scattered light from the inspection object is also emitted because the irradiation is performed in a flat state. For this reason, there is a risk that accuracy may be lowered depending on the surface state of the object to be inspected, and defects such as fine foreign matter cannot be stably detected.

  Scanning light is projected from the light projector so that the film which is pressed against the inspection roll and turned back at the inspection section is in contact with the film on the inspection roll. There is known a foreign matter detection method that reliably detects protrusion defects existing on the surface of a film by photoelectrically detecting scanning light that has passed through a film on an inspection roll (see Patent Document 2).

  However, the method described in Patent Document 2 is an effective method for a relatively large foreign matter of 5 μm or more, but in the case of a fine foreign matter of 1 μm or less close to the wavelength, it is difficult to make a difference due to the light diffraction effect. As a result, the detection accuracy becomes unstable and stable foreign object detection may not be possible.

  An irradiation area is formed by irradiating light from a direction inclined by a predetermined irradiation angle with respect to the normal direction of the inspection object surface with respect to the surface of the inspection object, and from the center of the irradiation area. There is known a method for accurately detecting a small size defect on the surface of an inspection object by providing a light detection means at a distant position (see Patent Document 3).

  However, although the method described in Patent Document 3 is suitable for detecting defects in a narrow range, the inspection object is large and it is difficult to detect foreign matter on the entire surface.

  A first deflecting plate is arranged on one side of the film and a second deflecting plate is arranged in a crossed Nicol state on the other side, and light is irradiated from the outside of the first deflecting plate by a linear light source. A method for inspecting a film is known that enables even a very small defect to be detected easily by receiving and analyzing light passing through a plate with a CCD line sensor (Patent Document 4). reference.). However, the method described in Patent Document 4 is an effective means when the object to be inspected is transparent or translucent, but can detect foreign matter adhering to the surface when the object to be inspected is opaque. It has a drawback that cannot be done.

Under such circumstances, it is desired to develop a foreign substance inspection apparatus and a foreign substance inspection method for accurately inspecting minute foreign substances existing on the surface even if the object to be inspected is transparent or opaque by detecting the foreign substance once. .
JP-A-8-304296 JP-A-8-128967 JP 2006-38477 A JP 2006-47143 A

  SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and its purpose is to detect a foreign matter on the surface and detect the foreign matter even if the object to be inspected is transparent or opaque by detecting the foreign matter once. It is to provide an inspection device.

  The above object of the present invention has been achieved by the following constitution.

  1. Foreign matter inspection for inspecting foreign matter using a foreign matter inspection device having an irradiation unit, a light receiving unit, and an image processing unit for foreign matter on the surface of a sheet-like object to be inspected that is supported and supported continuously by a support member In the method, the irradiating unit includes a light source unit and a scanning unit, and the inspection light from the light source unit is converted to a normal line at a contact point between the support member and the sheet-like object to be inspected by the scanning unit. In contrast, at an angle of 80 ° to 90 °, the support member and the sheet-like object to be inspected are irradiated in a tangential direction, and the scattered light of the inspection light irradiated and scattered by the foreign matter is received by the light receiving unit, A foreign matter inspection method, wherein information on a light receiving unit is analyzed by the image processing unit.

  2. The scanning unit uses the inspection light from the light source unit as a reference with respect to the contact point between the support member and the sheet-like object to be tested, and 1% to 30% of the diameter of the inspection light is below the normal line at the contact point 2. The foreign matter inspection method according to 1 above, wherein irradiation is performed in a tangential direction so as to perform irradiation.

  3. The scanning unit includes a parallel light conversion unit that converts inspection light from the light source unit into parallel light, and an optical reflection unit that is disposed on the opposite side of the inspection light irradiation direction at the same angle as the irradiation angle of the inspection light. The optical reflecting means passes through the contact point between the support member and the sheet-like object to be inspected and is configured to reflect the inspection light converted by the parallel light converting means in the tangential direction. 3. The foreign matter inspection method according to 1 or 2 above.

  4). The light receiving unit includes a light guide and a light receiving element, and the light guide is in a range of −60 ° to + 60 ° with respect to a normal line at a contact point between the support member and the sheet-like object to be inspected. 4. The foreign matter inspection method according to any one of 1 to 3, wherein the foreign matter inspection method is disposed at a position of 10 mm to 250 mm above the contact.

  5. 5. The foreign matter inspection method according to any one of 1 to 4, wherein the inspection light is laser light and is converted into parallel light by parallel light conversion means.

  6). 6. The foreign matter inspection method according to any one of 1 to 5, wherein a height of the foreign matter is 0.02 μm to 10 μm.

  7. In a foreign matter inspection apparatus having an inspection light irradiation unit, a light receiving unit, and an image processing unit that inspects a foreign matter on the surface of a sheet-like object to be inspected that is supported and supported continuously by a support member, the irradiation unit includes: A light source unit and a scanning unit, and the scanning unit emits inspection light from the light source unit at an angle of 80 ° to 90 ° with respect to a normal line at a contact point between the support member and the sheet-like object At this time, scanning is performed so as to irradiate the inspection light in a tangential direction between the support member and the sheet-shaped object to be inspected, and the scattered light of the inspection light irradiated and scattered by the foreign matter is received by the light receiving unit, A foreign matter inspection apparatus, wherein the information of the light receiving unit is analyzed by the image processing unit.

  8). With respect to the inspection light at the scanning unit, 1% to 30% of the diameter of the inspection light is irradiated in the downward direction of the normal line at the contact point with respect to the contact point between the support member and the sheet-like object to be inspected. 8. The foreign matter inspection apparatus according to 7 above, wherein irradiation is performed in a tangential direction and scanning is performed.

  9. The scanning unit includes a parallel light conversion unit that converts inspection light from the light source unit into parallel light, and an optical reflection unit that is disposed on the opposite side of the inspection light irradiation direction at the same angle as the irradiation angle of the inspection light. The optical reflecting means passes through the contact point between the support member and the sheet-like object to be inspected and is configured to reflect the inspection light converted by the parallel light converting means in the tangential direction. The foreign matter inspection apparatus according to 7 or 8, wherein

  10. The light receiving portion includes a light guide and a light receiving element, and the light guide is in the range of −60 ° to + 60 ° with respect to the normal line at the contact between the support member and the sheet-like object to be inspected. 10. The foreign matter inspection apparatus according to any one of 7 to 9, wherein the foreign matter inspection apparatus is disposed at a position of 10 mm to 250 mm in an upper portion of the head.

  11. 11. The foreign matter inspection apparatus according to any one of 7 to 10, wherein the inspection light is laser light.

  12 The foreign matter inspection apparatus according to any one of 7 to 11, wherein the height of the foreign matter is 0.02 μm to 10 μm.

  Even if the object to be inspected is transparent or opaque by detecting the foreign matter once, it is possible to provide a foreign matter inspection apparatus and foreign matter inspection method for inspecting the minute foreign matter existing on the surface. The efficiency of inspection work and high-precision inspection of foreign objects are now possible.

  Embodiments of the present invention will be described with reference to FIGS. 1 to 5, but the present invention is not limited thereto.

  FIG. 1 is a schematic diagram of a foreign matter inspection apparatus. This figure shows a foreign substance inspection apparatus for detecting foreign substances on the surface of a sheet-like object to be continuously conveyed.

  In the figure, reference numeral 1 denotes a foreign substance inspection apparatus. The foreign object inspection apparatus 1 includes an irradiation unit 101 that irradiates inspection light onto a foreign object on a belt-like sheet-like object 3 that is supported by a support member 2 and is continuously conveyed, and scattering of inspection light applied to the foreign object. A light receiving unit 102 that receives light and an image processing unit 103 that processes information from the light receiving unit 102 are provided.

  The irradiation unit 101 includes a light source unit 101a and a scanning unit 101b. The light source unit 101a includes a light source optical system 101a2 including a light source 101a1 and a cylinder lens, a collimator lens, and the like that collect inspection light from the light source 101a1. The scanning unit 101b includes a polygon mirror 101b1 that condenses the inspection light from the light source unit 101a in a line, a parallel light conversion unit 101b2 that converts the inspection light collected in a line into parallel light, and a parallel light conversion unit. And an optical reflecting means 101b3 for reflecting the inspection light converted into parallel light by 101b2. The inspection light is scanned by rotating the polygon mirror 101b1 at a constant speed, and is condensed on the sheet-like object 3 by the parallel light conversion means 101b2. A plurality of irradiation units 101 can be arranged in accordance with the width of the sheet-like object to be inspected. Although this figure shows a case where a polygon mirror is used, a method may be used in which the parallel light converting means 101b2 is directly irradiated with laser light to form sheet-like light without using the polygon mirror. .

  The parallel light conversion unit 101b2 is not particularly limited, and examples thereof include a parabolic mirror (parabolic mirror), an fθ lens, and the like. This figure shows a case where an fθ lens is used.

  As the optical reflecting means 101b3, the inspection light passing through the tangent at the contact point between the support member 2 of the belt-like sheet-like object 3 supported by the support member 2 and the belt-like sheet-like object 3 is reflected. If it can re-irradiate the foreign material on a tangent, there will be no limitation in particular, For example, a plane mirror, a phase serving mirror, etc. are mentioned. This figure has shown the case where a plane mirror is used. It is preferable that the optical reflecting means 101b3 is disposed at a position facing the irradiation direction of the inspection light at the same angle as the irradiation angle of the inspection light.

  In this way, by reflecting the inspection light that has passed through the tangent by the optical reflection means and re-irradiating the foreign matter on the tangential line, the amount of scattered light can be doubled without doubling the amount of inspection light. Improves accuracy.

  While the inspection light scans from the irradiation unit 101 toward the tangential direction of the support member 2 of the belt-like sheet-like object 3 supported by the support member 2 and continuously conveyed, and the sheet-like object 3. Irradiated. By irradiating and scanning the inspection light in the tangential direction, it is possible to narrow the irradiation region of the inspection light in the transport direction of the belt-like sheet-like object 3 and suppress scattered light from the sheet-like object. It is possible to increase the S / N ratio of scattered light from a foreign substance on the tangent line.

  The conveyance speed of the strip-shaped inspected object 3 is preferably 1 m / min to 10 m / min in consideration of foreign object detection accuracy, foreign object detection efficiency, and the like. The scanning speed of the inspection light is preferably determined as appropriate based on the conveyance speed of the strip-shaped inspected sheet 3 and the diameter of the inspection light.

  A semiconductor laser is used as the light source 101a. Examples of the semiconductor laser used include lasers in a visible region having a wavelength of 550 to 780 nm, an infrared region having a wavelength of 830 nm or more, and an ultraviolet region having a wavelength of 408 to 470 nm. Examples of the element used for the laser include a semiconductor laser, a gas laser, and a solid-state laser. The laser output is preferably 5 mW to 250 mW.

  The light receiving unit 102 is reflected by the scattered light C from the foreign matter 4 on the tangent irradiated by the inspection light irradiated in the tangential direction of the strip-shaped sheet-like object 3 supported by the support member 2 and the plane mirror 101b3. And a light receiving element 102b for receiving the scattered light C ′ from the foreign matter 4 on the tangent line re-irradiated with the inspection light. Scattered light C (C ′) is received by the light rod 102a, detected by the light receiving element 102b, and subjected to image processing by the image processing unit 103, thereby enabling analysis of the size and position of the foreign matter. It has become. The light receiving element shown in this figure is not particularly limited, and examples thereof include a photomultiplier tube (PMT), a CCD camera, and a photodiode (PD). This figure shows a case where a photomultiplier tube is used.

  The light rod 102a is disposed above the support member 2 in the width direction of the belt-like sheet-like object 3 and parallel to the tangent of the belt-like sheet-like object 3 supported by the support member 2. Yes.

  In the drawing, the light guide 102a is used for the light receiving unit 102, but a one-dimensional CCD camera (line sensor) may of course be used. Examples of the material used for the light rod include acrylic resin and quartz glass, and particularly preferable material is acrylic resin.

  A method for detecting foreign matter on the belt-like sheet-like object 3 using the foreign matter inspection apparatus 1 shown in this figure will be described. The inspection light A emitted from the light source 101a is condensed into a linear shape by a polygon mirror 101b1 rotating at a constant speed, and converted into parallel light B by an fθ lens 101b2 of parallel light conversion means. The parallel light B is irradiated while scanning in the tangential direction between the support member 2 and the sheet-like object to be inspected 3 that is supported by the support member 2 and continuously conveyed. When the foreign object 4 transported and adhered to the surface of the sheet-like object 3 comes to the tangent line between the sheet-like object 3 and the support member 2, the foreign object 4 is irradiated with the inspection light and irradiated. Part of the parallel light B, which is light, collides with the B foreign matter 4 and becomes scattered light C. On the other hand, the parallel light B, which is another inspection light, is reflected by the plane mirror 101b3 of the optical reflecting means disposed at a position facing the parallel light B (arranged at the same angle as the irradiation angle of the inspection light). ′ Is again irradiated with the foreign matter 4, and a part of the parallel light B as inspection light becomes scattered light C ′ by the foreign matter 4.

  The scattered light C and scattered light C ′ are received by the light guide 102 a, detected by the light receiving element 102 b, and subjected to image processing by the image processing unit 103, thereby analyzing the size of the foreign matter and the position of the foreign matter. The strip-like sheet-like object 3 shown in this figure can be used regardless of whether it is transparent or opaque.

Using the foreign substance inspection apparatus 1 shown in the figure, the tangent line between the support member 2 of the belt-like sheet-like object 3 supported by the support member 2 and continuously conveyed and the belt-like sheet-like object 3 The following effects can be obtained by irradiating the inspection light in the direction and detecting the foreign matter on the strip-shaped inspected sheet 3.
1. By irradiating inspection light in the tangential direction, it becomes possible to suppress scattered light that becomes noise, and it is possible to efficiently scatter scattered light from foreign substances existing on the tangent line, and to increase the S / N ratio. It has become possible to accurately detect foreign matter.
2. By disposing the optical reflecting means at the position facing the inspection light, the inspection light can be effectively used, and it is possible to detect foreign matter with high accuracy even with a low-power laser.

  FIG. 2 is a schematic plan view of FIG.

  In the figure, Q indicates the width of the light guide 102a. The width Q is preferably 110% to 120% with respect to the width of the strip-shaped sheet-like object 3 in consideration of the inspection range, the loss of received light, and the like. R indicates the width of the plane mirror 101b3. The width R is preferably 100% to 120% with respect to the width of the strip-shaped sheet-like object 3 in consideration of securing the inspection range, inspection accuracy, process layout, and the like. Other reference numerals are the same as those in FIG.

  FIG. 3 is a schematic sectional view taken along the line DD ′ of FIG.

  θ1 represents an angle between the center of the light rod 102a disposed above the contact 5 of the support member 2 and the sheet-like object 3 and the normal E at the contact 5. The angle θ1 is preferably −60 ° to + 60 ° with respect to the normal E at the contact point 5 in consideration of the angle of the scattered light of the minute foreign matter, the light receiving efficiency of the scattered light of the minute foreign matter, and the like. Note that −60 ° with respect to the normal E indicates that the light rod 102a is located on the left side of the normal E in the drawing, and + 60 ° with respect to the normal E indicates that the right side of the normal E in the drawing. Shows the case where the light rod 102a is located. In other words, 0 ° indicates a case where the light rod 102a is positioned on the normal line E.

  The diameter of the light rod 102a is preferably 30 mm to 60 mm in consideration of the light receiving efficiency of scattered light, the loss of the received scattered light, the reception of disturbance light, the detectability at the detection unit, and the like.

  S represents the distance between the center of the light rod 102a and the contact point 5, and the distance S is the angle of the scattered light of the minute foreign matter, taking into consideration the light receiving efficiency of the scattered light of the minute foreign matter, the diameter of the light rod, the intensity of the scattered light, etc. It is preferable that it is -250mm.

  θ2 indicates the angle of the inspection light irradiated in the tangential direction of the sheet-like object 3 at the contact 5 between the support member 2 and the sheet-like object 3. The angle θ <b> 2 is set to 80 ° to 90 ° with respect to the normal line at the contact 5. When the angle is less than 80 °, when the object to be inspected is a transparent body, noise is increased due to reflection inside the object to be inspected and reflection from the back surface, and foreign matter is not detected with high accuracy. When the angle exceeds 90 °, the inspection light does not reach in the tangential direction, and therefore, it is not preferable because it is impossible to detect foreign matter on the tangent.

  θ3 represents the angle of the optical reflecting means arranged at the position facing the inspection light. The angle θ3 is the same as the angle θ2 of the inspection light irradiated in the tangential direction with respect to the normal line at the contact point 5 in order to accurately reflect the inspection light irradiated in the tangential direction to the foreign matter on the tangential line. is required.

  T represents the distance between the surface of the fθ lens 101b2 and the contact 5, and the distance T is preferably 10 mm to 300 mm in consideration of the spot diameter of the inspection light (laser light), the focal depth, the size of the apparatus, and the like.

  U indicates the distance between the reflecting surface of the plane mirror 101b3 and the contact 5, and the distance U is preferably 50 mm to 200 mm in consideration of the concentration of the reflected light, the intensity of the reflected light, the size of the apparatus, and the like. Other reference numerals are the same as those in FIG.

  FIG. 4 is an enlarged schematic view of a portion indicated by Z in FIG.

  In the figure, V indicates the diameter of the inspection light. The diameter V is preferably 10 μm to 500 μm in consideration of the foreign matter detection accuracy, the size of the foreign matter, the irradiation efficiency with respect to the foreign matter, and the like.

  The inspection light converted into the parallel light B by the fθ lens 101c (see FIG. 1) is irradiated in the tangential direction between the sheet-like inspection object 3 and the support member 2, and on the sheet-like inspection object 3 at the contact point 5. However, it is preferable to irradiate the downward distance W of the normal line E from the contact 5 and the upper distance X at the same time. The distance W in the downward direction is 1% to 30% of the diameter V of the inspection light to be irradiated in consideration of noise caused by internal reflection when the object to be inspected is a transparent body, position variation during transportation of the object to be inspected, and the like. preferable. The upper distance X is a distance obtained by subtracting the downward distance W from the diameter V of the inspection light. Irradiating in the tangential direction means irradiating in the tangential direction within the irradiation range indicated by the distance X and the distance W.

  The height of the foreign material 4 is 0 in consideration of maintaining the functionality of optical films that require various high functions such as polarizing plate protective films, optical compensation films, antiglare films, polarizing films and retardation films. 0.02 μm to 10 μm is preferable.

  FIG. 5 is a schematic cross-sectional view showing a state of a sheet-like object to be inspected supported by support members having different cross-sectional shapes. Fig.5 (a) is a schematic sectional drawing which shows the state of the sheet-like to-be-inspected object supported by the support member with a circular cross-sectional shape. FIG. 5B is a schematic cross-sectional view showing a state of the sheet-like object to be inspected, in which the cross-sectional shape is a triangle and the portion that supports the sheet-like object is supported by a support member having an R shape.

  A description will be given of the support member 2 shown in FIG. By allowing the support member 2 to be rotated, the sheet-like object to be inspected 3 can be continuously conveyed while the contact member 5 between the support member 2 and the sheet-like object to be inspected 3 removes foreign matter on the sheet-like object to be examined 3. It can be detected by the foreign object inspection apparatus 1 (see FIG. 1). The diameter of the support member 2 is preferably 80 mm to 300 mm in consideration of inspection accuracy, damage to the sheet-like object to be inspected, and the like.

  θ4 is an angle (holding angle) sandwiched by a line connecting the center of the support member 2 and the point where the sheet-like object 3 is in contact with the support member 2 and the point where the sheet-like object 3 is separated from the support member 2. Indicates. The holding angle [theta] 4 is preferably 60 [deg.] To 270 [deg.] In consideration of the flatness during inspection of the sheet-like object to be examined, damage to the sheet-like object to be examined, and the like.

  The support member 2 'shown in FIG. The support member 2 'has a triangular cross-sectional shape and a portion that supports the sheet-like object to be inspected has an R shape. The support member 2 'shown in the figure fixes the sheet-like object 3' and is located on the sheet-like object 3 'at the contact point 5' between the support member 2 'and the sheet-like object 3'. This is suitable for detecting foreign matter with the foreign matter inspection apparatus 1 (see FIG. 1). R of the portion of the support member 2 ′ that supports the sheet-like object 3 ′ is the same as the diameter of the support member 2 shown in FIG.

  θ4 ′ is the center of the portion R of the support member 2 ′ that supports the sheet-like object 3 ′, the point where the sheet-like object 3 ′ contacts the support member 2 ′, and the sheet-like object 3 ′. The angle (holding angle) between the lines connecting the points away from the support member 2 'is shown. The angle (holding angle) θ4 ′ is the same as the angle (holding angle) θ4 shown in FIG.

  In addition, when using support member 2 'shown by FIG.5 (b), it is preferable to test | inspect in the state which stopped the sheet-like to-be-inspected object 3'. However, in the case where wrinkles may occur due to rubbing with the support member 2 ', inspection while transporting is also possible. When foreign matter detection is performed while transporting using the support member 2 'shown in this figure, a transparent or opaque belt-like sheet-like object 3' can be used as the sheet-like object 3 '. It is. When foreign matter detection is performed after stopping, it is preferable to use a transparent or opaque sheet-like inspection object 3 '.

  The sheet-like object to be inspected according to the present invention will be described. The sheet-like object to be inspected according to the present invention is not particularly limited, but is particularly effective for a sheet-like object to be inspected that affects the product performance due to the adhesion of fine foreign matters. For example, the film for optics used for a liquid crystal display device (LCD), the sealing film used for sealing of an organic EL element, etc. are mentioned.

  As an optical film, a transparent resin having excellent physical and mechanical properties and a small dimensional change with respect to temperature and humidity, such as cellulose resin, polycarbonate resin, polyarylate resin, polysulfone resin, polyethersulfone resin, norbornene Examples include films made from resins, polystyrene resins, polyacrylate resins, polyester resins, and the like.

  The film-like sealing member used for sealing the organic EL element has a multilayer structure in which a thermoplastic resin film material is used as a base material and a metal foil is laminated on a barrier layer. Examples of the base material include ethylene tetrafluoroethyl copolymer (ETFE), high density polyethylene (HDPE), stretched polypropylene (0PP), polystyrene (PS), polymethyl methacrylate (PMMA), stretched nylon (ONy), polyethylene terephthalate. Thermoplastic resin film materials used for general packaging films such as (PET), polycarbonate (PC), polyimide, and polyether styrene (PES) can be used. As these thermoplastic resin films, a multilayer film produced by coextrusion with a different film, a multilayer film produced by bonding with different stretching angles, etc. can be used as required. Further, it is naturally possible to combine the density and molecular weight distribution of the film used to obtain the required physical properties.

In the case of a thermoplastic resin film, it is necessary to form a barrier layer by vapor deposition or coating. Examples of the barrier layer include an inorganic vapor deposition film and a metal foil. As inorganic vapor deposition films, thin film handbooks p879-p901 (Japan Society for the Promotion of Science), vacuum technology handbooks p502-p509, p612, p810 (Nikkan Kogyo Shimbun), vacuum handbook revised editions p132-p134 (ULVAC Nippon Vacuum Technology Inorganic films as described in (1). For example, In, Sn, Pb, Au , Cu, Ag, Al, Ti, a metal such as _{Ni, MgO, SiO, SiO 2,} Al 2 O 3, GeO, NiO, CaO, BaO, Fe 2 O 3, Y 2 O ₃ , TiO ₂ , Cr ₂ O ₃ , Si _x O _y (x = 1, y = 1.5 to 2.0), Ta ₂ O ₃ , ZrN, SiC, TiC, PSG, Si ₃ N ₄ , single Crystalline Si, amorphous Si, W, etc. are used. Moreover, as a material of the metal foil, for example, a metal material such as aluminum, copper, or nickel, or an alloy material such as stainless steel or an aluminum alloy can be used, but aluminum is preferable in terms of workability and cost. The film thickness is about 1 to 100 μm, preferably about 10 to 50 μm. In order to facilitate handling during production, a film such as polyethylene terephthalate or nylon may be laminated in advance. When a resin film is used for the flexible sealing member, it is preferable to have a thermoplastic adhesive resin layer on the side in contact with the liquid sealing agent.

  Further, a protective layer may be provided on the barrier layer. The thickness of the protective layer is preferably 100 nm to 200 μm in consideration of stress cracking resistance, electrical insulation resistance of the barrier layer, adhesiveness (adhesive force, step following ability), etc. when used as a sealing agent layer. As the protective layer, a thermoplastic resin film having a JIS K 7210 standard melt flow rate of 5 to 20 g / 10 min is preferable, and a thermoplastic resin film of 6 to 15 g / 10 min or less is more preferably used. This is because if a resin with a melt flow rate of 5 (g / 10 min) or less is used, the gap formed by the steps of the extraction electrode of each electrode cannot be completely filled, and a resin of 20 (g / 10 min) or more cannot be filled. This is because if used, the tensile strength, stress cracking resistance, workability and the like are lowered. The thermoplastic resin film is not particularly limited as long as it satisfies the above numerical values. For example, low-density polyethylene (LDPE), which is a polymer film described in Toray Research Center, Inc., a new development of functional packaging materials, HDPE, linear low density polyethylene (LLDPE), medium density polyethylene, unstretched polypropylene (CPP), OPP, ONy, PET, cellophane, polyvinyl alcohol (PVA), stretched vinylon (OV), ethylene-vinyl acetate copolymer ( EVOH), ethylene-propylene copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, vinylidene chloride (PVDC), and the like can be used. Among these thermoplastic resin films, it is particularly preferable to use LDPE, LLDPE produced by using LDPE, LLDPE and a metallocene catalyst, or a film using a mixture of these films and HDPE films.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

Example 1
A cellulose acetate propionate film (optical film) was produced as a sheet-like object under the following conditions.

(Used resin)
Cellulose acetate propionate (acetyl group substitution degree 1.38, propionyl group substitution degree 1.30, number average molecular weight 80000, residual sulfuric acid content (as sulfur element) 50 ppm)
(Preparation of pellets)
Cellulose acetate propionate was heat-treated in dry air at 120 ° C. for 1 hour and allowed to cool to room temperature in dry air. After drying, the following composition was mixed with a Henschel mixer and then heated using an extruder to produce pellets and allowed to cool.

(Composition)
Cellulose acetate propionate 90 parts by mass Glycerin tribenzoate 10 parts by mass Tinuvin 928 (manufactured by Ciba Specialty Chemicals Co., Ltd., UV absorber)
2 parts by mass IRGANOX 1010 (manufactured by Ciba Specialty Chemicals, antioxidant)
0.2 parts by mass GSY-P101 (manufactured by Sakai Chemical Co., Ltd., antioxidant) 0.2 parts by mass Sumilizer GS (manufactured by Sumitomo Chemical Co., Ltd., antioxidant) 0.2 parts by mass (cellulose acetate propionate) Production of film)
The produced pellets were dried at 105 ° C. for 2 hours using a hot air dryer to remove moisture. Then, using a single screw extruder having a coat hanger type T die with a lip width of 1.5 m (Mitsubishi Heavy Industries, Ltd .: screw diameter 90 mm, T die lip material is tungsten carbide) A cellulose acetate propionate film having a film thickness of 80 μm and a length of 1000 m was prepared by winding it around a winding core at the collecting section. Extrusion conditions were performed in an environment of cleanliness class 100 at a pellet melting temperature of 230 ° C., screw rotation of 40 rpm / min, and extrusion rate of 50 kg / min.

(Surface foreign matter inspection)
The total length of the prepared cellulose acetate propionate film is converted into foreign matter on the cellulose acetate propionate film at the contact point between the support member and the cellulose acetate propionate film as shown in Table 1 using the foreign matter inspection apparatus shown in FIG. By changing the angle θ2 (see FIG. 3) of the inspection light to be irradiated, the foreign object detection test No. Table 1 shows the results of performing 101 to 105 and evaluating according to the evaluation rank shown below. The angle of the inspection light to be irradiated indicates an angle with respect to the normal line at the contact point between the support member and the moisture-proof film.

  The foreign matter inspection conditions were as follows. The conveyance speed of the cellulose acetate propionate film was set to 5 m / min, and the scanning speed of the inspection light was a 10-side polygon mirror at a rotational speed of 30000 rpm. The support member used was the support member shown in FIG. 5A having a diameter of 260 mm, and the holding angle θ4 (see FIG. 5) of the cellulose acetate propionate film to the support member was 210 °. As a light source for inspection light, gallium arsenide was used as an element, and a semiconductor laser having a wavelength of 408 nm (diameter: 12 μm) was set to have a laser output of 5 mW. The distance between the surface of the fθ lens and the contact point was 10 cm, and the distance between the reflecting surface of the plane mirror and the contact point was 10 cm. The height of the plane mirror was 10 mm, and the width of the plane mirror was 100% with respect to the width of the cellulose acetate propionate film. The angle θ3 (see FIG. 3) of the plane mirror was arranged according to the angle of the inspection light to be irradiated. The irradiation range of the inspection light (laser light) was such that the downward distance W (see FIG. 4) from the normal contact point at the contact point was 10% of the diameter of the inspection light (laser light).

  The arrangement position of the light rod is 0 ° (meaning that the light rod is disposed on the normal line) with respect to the normal line at the contact point between the support member and the cellulose acetate propionate film. The distance from the contact point was 100 mm. The light rod was made of acrylic resin, and the width was 120% with respect to the width of the cellulose acetate propionate film. The diameter of the light rod was 60 mm. In addition, the verification with respect to the height of the detected foreign material was confirmed by measuring the detected location with a digital microscope manufactured by Keyence Corporation.

(Evaluation rank for foreign matter inspection)
○: Foreign object detected △: Foreign object detection is unstable ×: Foreign object cannot be detected

  The effectiveness of the present invention was confirmed.

Example 2
(Preparation of sheet-like object to be inspected)
A cellulose acetate propionate film (optical film) was produced in the same manner as in Example 1.

(Surface foreign matter inspection)
The total length of the prepared cellulose acetate propionate film was changed by changing the installation position of the light rod used in the light receiving part as shown in Table 2 in the foreign matter inspection apparatus shown in FIG. Table 2 shows the results of performing 201 to 213 and evaluating according to the same evaluation rank as in Example 1.

  The foreign matter inspection conditions were as follows. The conveyance speed of the cellulose acetate propionate film was set to 5 m / min, and the scanning speed of the inspection light was a 10-side polygon mirror at a rotational speed of 30000 rpm. The support member shown in FIG. 5A having a diameter of 260 mm was used, and the holding angle θ4 (see FIG. 5) of the cellulose acetate propionate film to the support member was 210 °. As a light source for inspection light, gallium arsenide was used as an element, and a semiconductor laser having a wavelength of 408 nm (diameter: 12 μm) was set to have a laser output of 5 mW. The distance between the surface of the fθ lens and the contact point was 10 cm, and the distance between the reflecting surface of the plane mirror and the contact point was 10 cm. The height of the plane mirror was 10 mm, and the width of the plane mirror was 100% with respect to the width of the cellulose acetate propionate film. The angle θ3 (see FIG. 3) of the plane mirror was arranged according to the angle of the inspection light to be irradiated. The irradiation range of the inspection light (laser light) was such that the downward distance W from the normal contact point at the contact point was 10% of the diameter of the inspection light (laser light). The angle θ2 of the irradiated inspection light (see FIG. 3) was 90 °. In addition, the angle of the test | inspection light irradiated shows the angle with respect to the normal line in the contact point of a supporting member and a cellulose acetate propionate film.

  The light rod was made of acrylic resin, and the width was 120% with respect to the width of the cellulose acetate propionate film. The diameter of the light rod was 60 mm. In addition, the verification with respect to the height of the detected foreign material was confirmed by measuring the detected location with a digital microscope manufactured by Keyence Corporation.

  The effectiveness of the present invention was confirmed.

Example 3
(Preparation of sheet-like object to be inspected)
A cellulose acetate propionate film (optical film) was produced in the same manner as in Example 1.

(Surface foreign matter inspection)
Table 3 shows the entire length of the prepared cellulose acetate propionate film, and the irradiation range (downward distance W from the normal contact point at the contact point) shown in FIG. 4 with the foreign substance inspection apparatus shown in FIG. The foreign matter detection test No. Table 3 shows the results of performing 301 to 307 and evaluating according to the same evaluation rank as in Example 1. Note that the downward distance W from the normal contact point at the contact point indicates a ratio (%) to the diameter of the inspection light (laser light).

  The foreign matter inspection conditions were as follows. The conveyance speed of the cellulose acetate propionate film was set to 5 m / min, and the scanning speed of the inspection light was a 10-side polygon mirror at a rotational speed of 30000 rpm. The support member shown in FIG. 5A having a diameter of 260 mm was used, and the holding angle θ4 (see FIG. 5) of the cellulose acetate propionate film to the support member was 210 °. As a light source for inspection light, gallium arsenide was used as an element, and a semiconductor laser having a wavelength of 408 nm (diameter: 12 μm) was set to have a laser output of 5 mW. The distance between the surface of the fθ lens and the contact point was 10 cm, and the distance between the reflecting surface of the plane mirror and the contact point was 10 cm. The height of the plane mirror was 10 mm, and the width of the plane mirror was 100% with respect to the width of the cellulose acetate propionate film. The angle θ3 (see FIG. 3) of the plane mirror was arranged according to the angle of the inspection light to be irradiated. The angle θ2 of the irradiated inspection light (see FIG. 3) was 90 °. In addition, the angle of the test | inspection light irradiated shows the angle with respect to the normal line in the contact point of a supporting member and a cellulose acetate propionate film. The arrangement position of the light rod is 0 ° (meaning that the light rod is disposed on the normal line) with respect to the normal line at the contact point between the support member and the cellulose acetate propionate film. The distance from the contact point was 100 mm. The light rod was made of acrylic resin, and the width was 120% with respect to the width of the cellulose acetate propionate film. The diameter of the light rod was 60 mm. In addition, the verification with respect to the height of the detected foreign material was confirmed by measuring the detected location with a digital microscope manufactured by Keyence Corporation.

  The effectiveness of the present invention was confirmed.

Example 4
(Preparation of sheet-like object to be inspected)
A moisture-proof film was prepared in which a PET film having a thickness of 12 μm, a width of 1000 mm, and a length of 500 m was used as a base material and an aluminum foil having a thickness of 6 μm was adhered as an moisture-proof layer with an adhesive. The aluminum foil was bonded in an environment of cleanliness class 100.

(Surface foreign matter inspection)
As shown in Table 4, the entire length of the moisture-proof layer of the prepared moisture-proof film is measured by using the foreign substance inspection apparatus shown in Table 4 as follows. (See FIG. 3) Table 4 shows the results of performing 401 to 405 and evaluating according to the same evaluation rank as in Example 1. The angle of the inspection light to be irradiated indicates an angle with respect to the normal line at the contact point between the support member and the moisture-proof film.

  The foreign matter inspection conditions were as follows. The conveyance speed of the moisture-proof film was 5 m / min, and the scanning speed of the inspection light was 10 polygon mirrors rotated at 30000 rpm. The support member shown in FIG. 5A having a diameter of 260 mm was used, and the holding angle θ4 (see FIG. 5) of the moisture-proof film to the support member was 210 °. As a light source for inspection light, gallium arsenide was used as an element, and a semiconductor laser having a wavelength of 405 nm (diameter: 12 μm) was set to a laser output of 5 mW. The distance between the surface of the fθ lens and the contact point was 10 cm, and the distance between the reflecting surface of the plane mirror and the contact point was 10 cm. The height of the plane mirror was 10 mm, and the width of the plane mirror was 100% with respect to the width of the moisture-proof film. The angle θ3 (see FIG. 3) of the plane mirror was arranged according to the angle of the inspection light to be irradiated. The irradiation range of the inspection light (laser light) was such that the downward distance W from the normal contact point at the contact point was 1% of the diameter of the inspection light (laser light).

  The arrangement position of the light rod is 0 ° (meaning that it is disposed on the normal line) with respect to the normal line at the contact point between the support member and the moisture-proof film, and the distance between the center of the light beam and the contact point. Was 80 mm. The light rod is made of acrylic resin, and the width is 120% with respect to the width of the moisture-proof film. The diameter of the light rod was 60 mm. In addition, the verification with respect to the height of the detected foreign material was confirmed by measuring the detected location with a digital microscope manufactured by Keyence Corporation.

  The effectiveness of the present invention was confirmed.

Example 5
(Preparation of sheet-like object to be inspected)
The same band-shaped moisture-proof film was produced in the same manner as in Example 4.

(Surface foreign matter inspection)
The total length of the moisture-proof layer of the prepared moisture-proof film was changed by changing the installation position of the light rod used in the light receiving part as shown in Table 5 in the foreign substance inspection apparatus shown in FIG. Table 5 shows the results of evaluation in accordance with the same evaluation rank as in Example 1 after performing 501 to 513.

  The foreign matter inspection conditions were as follows. The conveyance speed of the moisture-proof film was 5 m / min, and the scanning speed of the inspection light was 10 polygon mirrors rotated at 30000 rpm. The support member shown in FIG. 5A having a diameter of 260 mm was used, and the holding angle θ4 (see FIG. 5) of the moisture-proof film to the support member was 210 °. As a light source for inspection light, gallium arsenide was used as an element, and a semiconductor laser having a wavelength of 405 nm (diameter: 12 μm) was set to a laser output of 5 mW. The distance between the surface of the fθ lens and the contact point was 10 cm, and the distance between the reflecting surface of the plane mirror and the contact point was 10 cm. The height of the plane mirror was 10 mm, and the width of the plane mirror was 100% with respect to the width of the moisture-proof film. The angle θ3 (see FIG. 3) of the plane mirror was arranged according to the angle of the inspection light to be irradiated. The irradiation range of the inspection light (laser light) was such that the downward distance W from the normal contact point at the contact point was 2% of the diameter of the inspection light (laser light). The angle θ2 of the irradiated inspection light (see FIG. 3) was 90 °. In addition, the angle of the test | inspection light irradiated shows the angle with respect to the normal line in the contact point of a support member and a moisture-proof film. The light rod is made of acrylic resin, and the width is 120% with respect to the width of the moisture-proof film. The diameter of the light rod was 60 mm. In addition, the verification with respect to the height of the detected foreign material was confirmed by measuring the detected location with a digital microscope manufactured by Keyence Corporation.

  The effectiveness of the present invention was confirmed.

It is a schematic diagram of a foreign material inspection apparatus. FIG. 2 is a schematic plan view of FIG. 1. It is a schematic sectional drawing in alignment with DD 'of FIG. FIG. 3 is an enlarged schematic view of a portion indicated by Z in FIG. 2. It is a schematic sectional drawing which shows the state of the sheet-like to-be-inspected object supported by the supporting member from which cross-sectional shape differs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Foreign substance inspection apparatus 101 Irradiation part 101a Light source 101b Polygon mirror 101c f (theta) lens 101d Plane mirror 102 Light receiving part 102a Light guide rod 102b Photomultiplier tube 103 Image processing part 2, 2 'Support member 3, 3' Sheet-like to-be-inspected object 4 Foreign object 5 Contact θ1, θ2, θ3 angles θ4, θ4 'angles (holding angles)
S, T, U, W, X Distance V Diameter

Claims (12)

Foreign matter inspection for inspecting foreign matter using a foreign matter inspection device having an irradiation unit, a light receiving unit, and an image processing unit for foreign matter on the surface of a sheet-like object to be inspected that is supported and supported continuously by a support member In the method
The irradiation unit has a light source unit and a scanning unit,
Inspection light from the light source unit is scanned by the scanning unit at an angle of 80 ° to 90 ° with respect to a normal line at a contact point between the support member and the sheet-like object to be inspected. Irradiate in the direction tangential to the specimen,
The scattered light of the inspection light irradiated and scattered on the foreign matter is received by the light receiving unit,
A foreign matter inspection method, wherein information of the light receiving unit is analyzed by the image processing unit. The scanning unit uses the inspection light from the light source unit as a reference with respect to the contact point between the support member and the sheet-like object to be tested, and 1% to 30% of the diameter of the inspection light is below the normal line at the contact point 2. The foreign matter inspection method according to claim 1, wherein irradiation is performed in a tangential direction so as to perform irradiation. The scanning unit includes a parallel light conversion unit that converts inspection light from the light source unit into parallel light, and an optical reflection unit that is disposed on the opposite side of the inspection light irradiation direction at the same angle as the irradiation angle of the inspection light. The optical reflecting means passes through the contact point between the support member and the sheet-like object to be inspected and is configured to reflect the inspection light converted by the parallel light converting means in the tangential direction. The foreign matter inspection method according to claim 1 or 2. The light receiving unit includes a light guide and a light receiving element, and the light guide is in a range of −60 ° to + 60 ° with respect to a normal line at a contact point between the support member and the sheet-like object to be inspected. The foreign matter inspection method according to any one of claims 1 to 3, wherein the foreign matter inspection method is disposed at a position of 10 mm to 250 mm above the contact. The foreign matter inspection method according to claim 1, wherein the inspection light is laser light and is converted into parallel light by parallel light conversion means. The foreign matter inspection method according to claim 1, wherein a height of the foreign matter is 0.02 μm to 10 μm. In a foreign matter inspection apparatus having an inspection light irradiation unit, a light receiving unit, and an image processing unit that inspects foreign matter on the surface of a sheet-like object to be inspected that is supported and supported continuously by a support member.
The irradiation unit has a light source unit and a scanning unit,
Inspection light from the light source unit is scanned by the scanning unit at an angle of 80 ° to 90 ° with respect to a normal line at a contact point between the support member and the sheet-like object to be inspected. Scan to irradiate the inspection light in the tangential direction with the inspection object,
The scattered light of the inspection light irradiated and scattered on the foreign matter is received by the light receiving unit,
A foreign matter inspection apparatus, wherein the information of the light receiving unit is analyzed by the image processing unit. With respect to the inspection light at the scanning unit, 1% to 30% of the diameter of the inspection light is irradiated in the downward direction of the normal line at the contact point with respect to the contact point between the support member and the sheet-like object to be inspected. The foreign matter inspection apparatus according to claim 7, wherein irradiation is performed in a tangential direction and scanning is performed. The scanning unit includes a parallel light conversion unit that converts inspection light from the light source unit into parallel light, and an optical reflection unit that is disposed on the opposite side of the inspection light irradiation direction at the same angle as the irradiation angle of the inspection light. And
The optical reflecting means passes through a contact point between the support member and the sheet-like object to be inspected, and is configured to reflect inspection light converted by the parallel light converting means in a tangential direction. The foreign matter inspection apparatus according to claim 7 or 8. The light receiving portion includes a light guide and a light receiving element, and the light guide is in the range of −60 ° to + 60 ° with respect to the normal line at the contact between the support member and the sheet-like object to be inspected. The foreign matter inspection device according to claim 7, wherein the foreign matter inspection device is disposed at a position of 10 mm to 250 mm in an upper portion of the head. The foreign matter inspection apparatus according to claim 7, wherein the inspection light is laser light. The foreign object inspection apparatus according to claim 7, wherein a height of the foreign object is 0.02 μm to 10 μm.

Images