WO2022044951A1 - 検査方法 - Google Patents

検査方法 Download PDF

Info

Publication number
WO2022044951A1
WO2022044951A1 PCT/JP2021/030363 JP2021030363W WO2022044951A1 WO 2022044951 A1 WO2022044951 A1 WO 2022044951A1 JP 2021030363 W JP2021030363 W JP 2021030363W WO 2022044951 A1 WO2022044951 A1 WO 2022044951A1
Authority
WO
WIPO (PCT)
Prior art keywords
retardation
plate
phase difference
film
inspected
Prior art date
Application number
PCT/JP2021/030363
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
信次 小林
俊介 松田
Original Assignee
住友化学株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 住友化学株式会社 filed Critical 住友化学株式会社
Priority to CN202180046819.XA priority Critical patent/CN115867780A/zh
Publication of WO2022044951A1 publication Critical patent/WO2022044951A1/ja

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/958—Inspecting transparent materials or objects, e.g. windscreens
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements

Definitions

  • the present invention relates to an inspection method.
  • a polarizing plate used in a liquid crystal display device, an organic EL display device, or the like is generally configured with a polarizing element sandwiched between two protective films.
  • an adhesive layer is laminated on one of the protective films, and a release film is further laminated on the adhesive layer. Further, in many cases, a release film (surface protective film) that protects the surface of the other protective film is also attached.
  • the polarizing plate is distributed and conveyed in a state where the release films are laminated in this way, and the release film is peeled off when the polarizing plate is attached to the display device in the manufacturing process of the display device.
  • defects By the way, in the manufacturing stage of the polarizing plate, if foreign matter is mixed between the polarizing element and the protective film, bubbles remain, or if the protective film has the function of a retardation film, an orientation defect is inherent. (Hereinafter, these foreign substances, bubbles and orientation defects are collectively referred to as "defects").
  • the defective portion When a polarizing plate having a defect is attached to a display device, the defective portion may be visually recognized as a bright spot, or the image may appear distorted at the defective portion. In particular, defects visually recognized as bright spots are easily visible when the display device displays black.
  • an inspection for detecting the defect of the polarizing plate is performed.
  • the inspection of this defect is generally an optical inspection using the polarization axis of the polarizing plate.
  • a polarizing filter is provided between the polarizing plate to be inspected and the light source, and then the polarizing plate or the polarizing filter is rotated in the plane direction.
  • Each of these polarization axis directions has a specific relationship.
  • the linearly polarized light passing through the polarizing filter does not pass through the polarizing plate.
  • the polarizing plate and the polarizing filter are parallel to each other in the polarization axis direction, the linearly polarized light that has passed through the polarizing filter passes through the polarizing plate.
  • the linear polarization is blocked at the portion, and the presence of the defect is found by not detecting the light.
  • the inspector visually detects the light transmitted through the polarizing plate, or automatically detects it by the image analysis processing value obtained by combining the CCD camera and the image processing device, thereby inspecting the presence or absence of defects in the polarizing plate. It can be carried out.
  • the polarizing plate when the polarizing plate includes a release film, the polarization characteristics of the polarizing plate are impaired by the birefringence of the release film, so that defects such as bright spots existing in the polarizing plate in the conventional inspection apparatus are present. could not be detected accurately.
  • the polarizing plate is a circular polarizing plate and the release film is made of a polyethylene terephthalate resin (PET resin), a phase difference filter (corresponding to the above polarizing filter) suitable for the wavelength dispersion of the PET resin to some extent is used.
  • PET resin polyethylene terephthalate resin
  • a phase difference filter suitable for the wavelength dispersion of the PET resin to some extent is used.
  • the circularly polarizing plate and the retardation filter are arranged so as to form a cross Nicol, the defect is visually recognized as a bright spot according to the above principle, but the retardation film of the circularly polarizing plate has.
  • the bright spot defect may be visually recognized as a black spot, and in that case, it is more difficult to determine the detection than to detect it as a bright spot. This tendency is particularly remarkable when the circularly polarizing plate contains a retardation film made of a cured product of a polymerizable liquid crystal compound.
  • the circularly polarizing plate may have an irregular shape.
  • a recess may be provided on the outer periphery of the circular polarizing plate, the corners of the outer periphery may be rounded, or a through hole may be provided.
  • an object of the present invention is to provide an inspection method capable of easily determining the presence or absence of defects in a deformed circularly polarizing plate.
  • the present invention is an inspection method for determining the presence or absence of defects in a film-shaped object to be inspected, which comprises a release film made of a circular polarizing plate and a polyethylene terephthalate resin (hereinafter, may be referred to as "PET resin"). Therefore, the object to be inspected has a shape having a concave portion recessed from the side of the rectangle toward the inside of the rectangle with respect to the rectangle, or a shape in which the corners of the rectangle are curved, or a rectangular shape.
  • PET resin polyethylene terephthalate resin
  • the shape has a through hole at a position away from the side, and the in-plane retardation value of the light source, the first retardation filter, the first retardation plate, the object to be inspected, and the in-plane retardation value at a wavelength of 550 nm is that of the release film. It is substantially the same as the in-plane retardation value at a wavelength of 550 nm (hereinafter, the in-plane retardation value at this wavelength of 550 nm may be referred to as “Re (550)”), and compensates for the double bending of the release film.
  • the second retardation plate, the first retardation filter, and the second retardation filter constituting the circular polarizing plate and the cross Nicol are arranged in this order on the optical path of the light emitted by the light source.
  • Re (550) is substantially the same as Re (550) of the second retardation plate, and the compound refraction of the second retardation plate is compensated.
  • Light is incident on the object to be inspected from the light source, and the presence or absence of defects in the circularly polarizing plate is determined by observing from the opposite side of the light source.
  • a third retardation plate and a fourth retardation plate which are 50 to 100 nm larger than the Re (550) of the release film and compensate for the compound refraction of the release film, respectively, and are inspected after the replacement.
  • an inspection method in which light is incident on an object and observed from the opposite side of the light source to determine the presence or absence of defects in the circularly polarizing plate.
  • substantially the same in Re (550) means that the difference in Re (550) is only about ⁇ 5 nm.
  • each of these retardation plates is used as the third retardation plate and the fourth retardation plate.
  • the first phase difference filter and the second phase difference filter are arranged so as to form a cross Nicol, when the object to be inspected does not exist on the optical path, the light source is used. The light is blocked by the second phase difference filter. Therefore, light leakage from the deformed portion of the object to be inspected is significantly suppressed, and there is no hindrance when inspecting the vicinity of the deformed portion. From the above, the inspection method of the present invention can easily determine the presence or absence of defects in the irregularly shaped circular polarizing plate.
  • the object to be inspected is further provided with a surface protective film made of PET-based resin on the side opposite to the side where the release film is provided with respect to the circularly polarizing plate, and the first retardation plate and the object to be inspected.
  • a high retardation plate having a Re (550) of 5000 nm or more may be further arranged between the two.
  • the in-plane phase difference of the surface protective film may cause an iridescent pattern in the observation field of inspection, which may hinder defect observation.
  • a high retardation plate having a high in-plane retardation it is possible to convert the rainbow-colored light into white light so as not to interfere with the observation.
  • the slow axis of the surface protection film and the slow axis of the high retardation plate are arranged so as to be substantially parallel to each other. Since the in-plane phase difference is additive, rainbow-colored light can be reliably converted to white light by making the slow-phase axes substantially parallel to each other.
  • the circular polarizing plate may have a retardation film made of a cured product of a polymerizable liquid crystal compound.
  • the retardation film is made of a cured product of a polymerizable liquid crystal compound, its general thinness increases the possibility of observing it as a black spot defect. Therefore, it is suitable as an object to which the present invention is applied.
  • the object to be inspected the first phase difference plate, the second phase difference plate, the third phase difference plate, the fourth phase difference plate, the first phase difference filter, and the first phase difference plate are used.
  • At least one of the two retardation filters, the first retardation plate, and the second retardation plate may be tilted so as to face each other at different angles, or may be rotated in a direction perpendicular to the optical path. You may let me. By tilting these, the phase difference of the release film, the first and second phase difference plates, and the like can be finely adjusted, so that a wider range of inspection becomes possible. Further, by rotating these, it becomes easy to align the axes of each configuration.
  • the first retardation plate and the third retardation plate may be configured by being arranged in the same member.
  • FIG. 3 is a sectional view taken along line III-III of the object to be inspected. It is a figure which shows an example of a retardation plate. It is a figure which shows the inspection apparatus of 2nd Embodiment.
  • the inspection device 100A includes a light source 2, a first phase difference filter 3A, a first phase difference plate 4A, a second phase difference plate 4B, and a second phase difference filter 3B. Are arranged in this order.
  • the film-shaped inspected object 10 to be inspected is a circular polarizing plate having a deformed shape with reference to a rectangle, and is recessed from one side of the rectangle toward the inside of the inspected object 10. It has a recess R.
  • "based on a rectangle” means that the shape of the object to be inspected 10 forms a rectangle when it is assumed that the concave portion R does not exist.
  • the corners of the object to be inspected 10 are processed so as to be curved.
  • the "variant shape” refers to a shape in which a part of a shape such as a polygon, a perfect circle, or an ellipse is deformed. Deformation means providing a recess on the outer circumference, rounding a corner, making a curve straight, or providing a through hole.
  • the object to be inspected 10 includes a circularly polarizing plate 1 which is a main body to be inspected, and a release film 16a laminated on the circularly polarizing plate 1 via an adhesive layer 15. ing.
  • protective films 12a and 12b are bonded to both sides of the polarizing film 11, and further, a retardation film 14 is formed on the protective film 12a on the side provided with the release film 16a via an adhesive layer 13. It is formed.
  • a surface protective film 16b is laminated on the surface of the circular polarizing plate 1 on the side not provided with the release film 16a.
  • the circular polarizing plate 1 is generally used for a display device, for example, a liquid crystal display device or an organic EL display device, and when used, the release film 16a is peeled off and attached to the display device via the pressure-sensitive adhesive layer 15. ..
  • circular polarizing plate includes a circular polarizing plate and an elliptical polarizing plate.
  • circularly polarized light includes circularly polarized light and elliptically polarized light.
  • the polarizing film 11 is a film that converts the light incident from the surface protective film 16b side into linear polarization in the inspection device 100A.
  • Examples of the polarizing film 11 include a polyvinyl alcohol film in which iodine and a dichroic dye are adsorbed and oriented, and a film in which a polymerizable liquid crystal compound is oriented and polymerized, and a dichroic dye is adsorbed and oriented. Can be mentioned.
  • the protective films 12a and 12b are for protecting the polarizing film 11.
  • those widely used in the technical field of polarizing plates are used for the purpose of obtaining a polarizing plate having appropriate mechanical strength.
  • a cellulose ester film such as a triacetyl cellulose (TAC) film; a cyclic olefin film; a polyester film such as a polyethylene terephthalate (PET) film: a (meth) acrylic film such as a polymethylmethacrylate (PMMA) film. It is a film or the like.
  • an additive widely used in the technical field of the polarizing plate may be contained in the protective film.
  • the protective films 12a and 12b are attached to the display device together with the polarizing film 11 as a component of the circularly polarizing plate 1, strict control of the phase difference value or the like is required.
  • the protective film 12a a film having an extremely small retardation value is preferably used.
  • the protective film 12b for example, a film having a phase difference of ⁇ / 4 or a film having a small phase difference value is used for easy viewing when the display device is visually recognized through polarized sunglasses.
  • the protective films 12a and 12b are attached to the polarizing film 11 via an adhesive.
  • the retardation film 14 is a film that converts light linearly polarized by the polarizing film 11 into circular polarization in the inspection device 100A.
  • the retardation film 14 is not particularly limited as long as it is a film having a retardation, but may be a laminated ⁇ / 2 film and a ⁇ / 4 film. In this case, the ⁇ / 2 film and the ⁇ / 4 film may be in this order from the closest to the polarizing film 11.
  • the retardation film 14 is made of a cured product of a polymerizable liquid crystal compound.
  • the retardation film 14 made of a cured product of a polymerizable liquid crystal compound is usually as thin as about 0.2 ⁇ m to 10 ⁇ m, and when foreign matter or the like is contained, the retardation value tends to decrease at that portion. In such a portion, as will be described later, when the birefringence of the release film 16a is compensated by the retardation plate 4, it is observed as a black spot even though it should be observed as a bright spot defect. May occur.
  • the polymerizable liquid crystal compound capable of forming the retardation film 14 is described in, for example, JP-A-2009-173893, JP-A-2010-31223, WO2012 / 147904, WO2014 / 10325 and WO2017-433438.
  • the disclosed ones can be mentioned.
  • the polymerizable liquid crystal compounds described in these publications can form a retardation film having so-called anti-wavelength dispersibility, which enables uniform polarization conversion in a wide wavelength range.
  • an extremely thin retardation film can be formed as described above.
  • a circularly polarizing plate having such a retardation film can form a circularly polarizing plate having an extremely thin thickness.
  • Such a circularly polarizing plate having an extremely thin thickness is advantageous as a circularly polarizing plate for flexible display materials, which has been attracting attention in recent years.
  • Examples of the base material to which the polymerizable liquid crystal compound solution is applied include those described in the above-mentioned publication.
  • Such a base material may be provided with an alignment film for orienting the polymerizable liquid crystal compound.
  • the alignment film may be either one that is photo-aligned by polarization irradiation or one that is mechanically oriented by a rubbing treatment.
  • the alignment film is also described in the above publication.
  • the coating film itself obtained by applying the polymerizable liquid crystal compound solution is defective. May occur.
  • the alignment film is subjected to the rubbing treatment, debris of the rubbing cloth remains on the alignment film, which may cause a defect in the coating film of the polymerizable liquid crystal compound solution (composition for forming a liquid crystal cured film).
  • the retardation film formed from the polymerizable liquid crystal compound can form a retardation film having an extremely thin thickness, but there is a factor that causes defects. Then, as will be described later, the defect of the retardation film may cause a defect observed as a black spot.
  • the inspection apparatus and inspection method of the present embodiment are particularly useful in detecting the presence or absence of defects in an object to be inspected having a circularly polarizing plate having a retardation film having such defects and a release film.
  • the retardation film 14 can be produced by applying a composition for forming an alignment film on a substrate and further applying a composition for forming a liquid crystal cured film containing a polymerizable liquid crystal compound on the composition.
  • the retardation film 14 thus created is attached to the pressure-sensitive adhesive layer 13 formed on the protective film 12a together with the base material, and then the base material is peeled off to protect the retardation film 14 from the protective film 12a. Can be transferred onto.
  • the release film 16a is peeled off from the circular polarizing plate 1 when it is attached to the display device, and the peeled release film 16a is usually discarded. Therefore, unlike the protective films 12a and 12b, strict control of the phase difference value is not required. Therefore, when a commercially available film is used as the release film 16a, if the phase difference value is not compensated, a malfunction may occur in the defect inspection. That is, in the defect inspection of the circular polarizing plate 1 to which the release film 16a whose retardation value is not strictly controlled is adhered, the phase difference of the release film 16a reduces the inspection accuracy of the inspection device 100A. Can be.
  • a surface protective film 16b which is a kind of release film, is often provided on the opposite surface of the release film 16a.
  • the surface protective film 16b is bonded to the protective film 12b side.
  • This surface protective film 16b is also usually peeled off from the circularly polarizing plate 1 when it is attached to a display device, and unlike the protective films 12a and 12b, strict control of the retardation value is not required. ..
  • the protective film 12b and the surface protective film 16b may be bonded to each other via an appropriate adhesive layer or adhesive layer (in FIG. 3, this adhesive layer or adhesive layer). Is not shown).
  • the release film 16a is made of a PET-based resin.
  • the surface protective film 16b one made of PET-based resin is used.
  • the film made of PET-based resin has an advantage that it is versatile as a release film and is inexpensive.
  • the inexpensive PET-based resin film does not require strict control of the phase difference value. Therefore, for example, the phase difference value may vary from product lot to product lot. Further, even if the same PET resin film is used, the phase difference value may vary in the plane. Even with a circularly polarizing plate in which such an inexpensive PET resin-based film is bonded as a release film, the presence or absence of defects can be accurately detected by the inspection method of the present embodiment.
  • the slow axis of the release film 16a and the slow axis of the surface protection film 16b are bonded so as to be substantially parallel to each other.
  • Re (550) of the release film 16a is shown.
  • these release films are PET-based resin films, and such films are readily available on the market.
  • a piece having a size of about 40 mm ⁇ 40 mm is separated from this film (from a long film, separated using an appropriate cutting tool, etc.).
  • Re (550) of this piece is measured three times, and the average value of Re (550) is obtained.
  • One piece of Re (550) can be measured at a measurement temperature of room temperature (about 25 ° C.) using a phase difference measuring device KOBRA-WPR (manufactured by Oji Measuring Instruments Co., Ltd.). The same test may be performed when Re (550) of the surface protective film 16b is obtained.
  • KOBRA-WPR manufactured by Oji Measuring Instruments Co., Ltd.
  • the light source 2 various commercially available products can be used, but it is advantageous that the light source 2 is, for example, linear light such as laser light (including one that approximates straight light).
  • the light emitted by the light source 2 is unpolarized and passes through the first phase difference filter 3A described later to be polarized in a predetermined direction.
  • the first phase difference filter 3A and the second phase difference filter 3B are both circular polarizing plates.
  • the orientation of the second phase difference filter 3B is always adjusted so as to form a cross Nicol with the first phase difference filter 3A when inspecting the object 10 to be inspected.
  • the second retardation plate 4B compensates for the birefringence of light due to the release film 16a included in the object 10 to be inspected.
  • the material constituting the second retardation plate 4B is not particularly limited as long as it compensates for the birefringence of light due to the release film 16a made of PET-based resin. It is also possible to prepare a commercially available retardation plate having a Re (550) of 100 to 200 nm, and stack a plurality of these to obtain a desired retardation value to form the second retardation plate 4B. Since Re (550) is usually additive, a second retardation plate 4B of the desired Re (550) can be obtained from the laminated retardation plates Re (550).
  • the first retardation plate 4A cancels the phase difference of the second retardation plate 4B, and it is preferable to use one having the same configuration as the second retardation plate 4B.
  • the release film 16a made of PET resin usually has a large variation in the in-plane retardation value and the slow phase axis, a plurality of types of retardation plates are prepared so that a plurality of phase difference values can be selected at the time of inspection. It is preferable to keep it.
  • a two-disc set of a first retardation plate 4A and a second retardation plate 4B having substantially the same retardation value as Re (550) of the release film 16a, and Re (550) of the release film 16a.
  • At least two types of retardation plates are used, which are a two-disc set of a third retardation plate and a fourth retardation plate of Re (550) having a size of 50 to 100 nm.
  • the first retardation plate 4A and the second retardation plate 4B used as a pair have substantially the same Re (550)
  • the third retardation plate and the fourth retardation plate have substantially the same Re (550).
  • the retardation value substantially the same as Re (550) of the release film 16a means that the absolute value of the difference between Re (550) of the release film 16a and Re (550) of the retardation plate is 20 nm or less. To say.
  • the first and second retardation plates 4A and 4B show a phase difference in the range of about ⁇ 300 nm with respect to Re (550) of the release film. It is preferable that the film is made. Within the range of this phase difference, it is preferable to further change the release film in the in-plane direction in increments of 50 nm to 100 nm. It is preferable to prepare various retardation plates showing these phase differences. That is, as a series of phase difference plates for changing the phase difference, it is preferable to prepare a phase difference plate having a different phase difference in addition to the first phase difference plate 4A and the third phase difference plate. Next, the state of this retardation plate will be described.
  • FIG. 4 shows an outline of a series of retardation plates 4 in which retardation plates having different retardations are integrated.
  • the retardation plate 4 is configured such that regions having different in-plane retardation values are connected in one direction in one retardation plate member. good. That is, the region located at the end (first region a 1 ; corresponding to the first retardation plate) is a region where Re (550) is, for example, 1720 nm, and a region adjacent to the region (second region). Region a 2 ; corresponding to the third retardation plate) is a region where Re (550) is 1790 nm, and a region adjacent to the region (third region a 3 ; corresponding to the fifth retardation plate).
  • This retardation plate 4 can be used not only as a first retardation plate 4A arranged next to the first retardation filter 3A when viewed from the light source 2 side, but also in front of the second retardation filter 3B. It is used at the same time as the second retardation plate 4B arranged in.
  • the first region a1, the second region a2, and the third region a3 are the second retardation plate, the fourth retardation plate, and the sixth region, respectively. It becomes the phase difference plate of.
  • the regions having the same Re (550) for example, the first regions a1 and the second
  • Areas a 2 are used as a pair.
  • Detection including a CCD camera or the like on the optical path 9 and at a position on both sides of the second phase difference filter 3B opposite to the side where the light source 2 is located in order to observe the light that has passed through the object 10 to be inspected.
  • Means 5 may be arranged. For example, it can be automatically detected by image processing analysis in which a CCD camera and an image processing device are combined, thereby inspecting the object to be inspected.
  • the detecting means 5 may not be a member, but a human may visually observe the second phase difference filter 3B.
  • the inspection device 100A has an angle at which at least one of the inspected object 10, the first and second retardation plates 4A and 4B, and the first and second retardation filters 3A and 3B faces each other. It is preferable to have a movable device (not shown) capable of tilting differently or rotating in a direction perpendicular to the optical path 9 of light. By tilting these, the phase difference of the release film 16a made of PET-based resin and the first and second retardation plates 4A and 4B can be finely adjusted, so that a wider range of inspection becomes possible. Further, by rotating these, the release film 16a made of PET-based resin and the first and second retardation plates 4A and 4B can be easily aligned with each other.
  • the inspection method using the inspection device 100A is as follows. First, the object to be inspected 10 is inserted between the first retardation plate 4A and the second retardation plate 4B inside the inspection device 100A. At this time, the surfaces of the films are all parallel to each other, and the side of the object 10 provided with the release film 16a faces the side opposite to the light source 2, and the phase difference between the circularly polarizing plate 1 and the second. Arranged so that the filter 3B and the filter 3B form a cross Nicol.
  • the first retardation plate 4A and the second retardation plate 4B the retardation plate 4 shown in FIG. 4 is used, and in each case, the first region a1 is on the optical path 9. It is arranged so that it is located in.
  • the first phase difference filter 3A is adjusted to form a cross Nicol with the second phase difference filter 3B.
  • the relative positional relationship of each film may be changed by the movable device to form a cross Nicol after the object 10 to be inspected is inserted in an arbitrary direction.
  • the light emitted by the light source 2 is incident on the first retardation filter 3A, passes through this to become circularly polarized light, and subsequently passes through the first retardation plate 4A.
  • the recess R of the object to be inspected 10 passes through the first retardation filter 3A and the first retardation plate 4A.
  • the resulting light is incident on the second retardation plate 4B as it is, and is blocked by the first retardation filter 3A and the second retardation filter 3B as a cross Nicol. When this is observed from the detection means 5 side, the surface of the second phase difference filter 3B is dark.
  • the release film 16a has a phase difference
  • the circular polarization that has passed through the object to be inspected 10 is affected, and the amount of light transmitted through the second phase difference filter 3B increases (for example, 5% of the light amount of the light source or). It becomes more than 10%), and the detection accuracy of defects such as bright spots existing in the circular polarizing plate 1 is lowered.
  • the second retardation plate 4B is arranged between the inspected object 10 and the second retardation filter 3B, so that the retardation value of the release film 16a in the inspected object 10 is cancelled. , Compensates for the birefringence of light due to the release film 16a.
  • the second retardation plate 4B is designed so that the retardation value and the wavelength dispersion characteristic of the release film 16a match as much as possible in order to effectively compensate for the birefringence of light due to the release film 16a. Due to the in-plane variation of the phase difference value of the release film 16a, it is difficult to sufficiently block light in the entire inspection field for inspection. In such a case, the optical compensation is matched at the portion of the circular polarizing plate 1 where the retardation value of the retardation film 14 is lowered, and the defect that should be originally observed as a bright spot is observed as a black spot. It can happen.
  • black spot defects have a smaller effect on legibility than bright spot defects, so even if the defect size is larger than the bright spot defects, it is often acceptable, and as a result, it is judged that there is no problem. It may end up.
  • the black spot defect should be originally observed as a bright spot defect caused by a retardation value lowering portion of the retardation film 14, it has a great influence on visibility and becomes a problem.
  • the third retardation plate and the third retardation plate having an in-plane retardation different from those of the first retardation plate 4A and the second retardation plate 4B with respect to the defect portion visually recognized as the black spot.
  • a fourth retardation plate is used. Specifically, both the first and second retardation plates 4A and 4B are slid in the in-plane direction, and both are in the second region a2 (third retardation plate, fourth retardation plate). Is located on the optical path 9. A second inspection is performed with this arrangement.
  • the possibility that the defects are observed as bright spot defects is increased, and the defects can be easily recognized correctly. If a black spot is found again in the inspection using the second region a2 (third retardation plate, fourth retardation plate), the two retardation plates 4 and 4 are further added to the third. Slide to region a3 (fifth retardation plate, sixth retardation plate) and perform the third inspection.
  • At least one of the inspected object 10, the first and second retardation plates 4A and 4B, and the first and second retardation filters 3A and 3B are tilted so as to face each other at different angles. It may be rotated in the direction perpendicular to the optical path 9 of the light. By tilting, the phase difference between the release film 16a and the first and second retardation plates 4A and 4B can be finely adjusted, so that a wider range of inspection becomes possible. Further, by rotating these, the release film 16a made of PET-based resin and the first and second retardation plates 4A and 4B can be easily aligned with each other. These operations can be performed particularly easily when the inspection device 100A includes a movable device.
  • the portion where the black defect was observed in the inspection using the pair of the first retardation plate 4A and the second retardation plate 4B is the third retardation plate (a 2 ). And by inspecting using the fourth phase difference plate (a 2 ), it is possible to adjust the phase difference so that this can be observed as a bright spot defect. Further, in this inspection method, since the first phase difference filter 3A and the second phase difference filter 3B are arranged so as to form a cross Nicol, when the object to be inspected 10 does not exist on the optical path, the inspection object 10 is not present. The light from the light source is blocked by the second phase difference filter.
  • ⁇ Second embodiment> The inspection method of the second embodiment will be described.
  • the difference between the inspection method of the second embodiment and the inspection method of the first embodiment is that, as shown in FIG. 5, in the inspection device 100B, the first retardation plate 4A and the object to be inspected 10 are used. It is a point where the high retardation plate 20 is arranged between them.
  • the high retardation plate 20 is a film having the same shape as the object to be inspected 10, and has a similar recess R'at a position corresponding to the recess R of the object to be inspected 10. Since the high retardation plate 20 complements the retardation value of the surface protection film 16b, it is preferably made of the same material as the surface protection film 16b, and is preferably made of a polyethylene terephthalate resin.
  • the high retardation plate 20 preferably has a Re (550) of 5000 nm or more, more preferably 7,000 nm or more, further preferably 8,000 nm or more, and particularly preferably 10,000 nm or more. Further, it is preferable that the high phase difference plate 20 is arranged so that its slow phase axis is substantially parallel to the slow phase axis of the surface protection film 16b.
  • the coloring of the observed light due to the interference of light caused by the phase difference of the surface protective film 16b is suppressed. be able to. That is, the in-plane retardation of the surface protective film 16b may cause a rainbow-colored pattern in the observation field of inspection to hinder defect observation, but the high retardation plate 20 has a high in-plane retardation value. , The rainbow-colored light can be converted into white light so as not to interfere with the observation.
  • the iridescent light is converted into light outside visible light due to the additive nature of the in-plane phase difference. It can be converted reliably.
  • the present invention is not limited to the above embodiment.
  • the first retardation filter 3A and the first retardation plate 4A are shown as separate articles from each other, but these constitute one film as a laminated body laminated with each other. May be good.
  • the second retardation filter 3B and the second retardation plate 4B may be formed as one laminated body.
  • the retardation plate 4 may have a configuration in which regions having different Re (550) are arranged in a ring shape.
  • a disk-shaped film is divided into a plurality of regions having different retardation values with a virtual line extending radially from the center as a boundary, and a certain region (first region; corresponding to the first retardation plate) is Re.
  • the adjacent region (third region; corresponding to the third retardation plate) may be a region where Re (550) is 1860 nm.
  • the number of the regions is arbitrary, and may be, for example, four, six, eight, or the like.
  • the present invention can be used for quality inspection of circularly polarizing plates.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Analytical Chemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Biochemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Optics & Photonics (AREA)
  • Polarising Elements (AREA)
  • Testing Of Optical Devices Or Fibers (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
  • Liquid Crystal (AREA)
PCT/JP2021/030363 2020-08-28 2021-08-19 検査方法 WO2022044951A1 (ja)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202180046819.XA CN115867780A (zh) 2020-08-28 2021-08-19 检查方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2020144837A JP7413209B2 (ja) 2020-08-28 2020-08-28 検査方法
JP2020-144837 2020-08-28

Publications (1)

Publication Number Publication Date
WO2022044951A1 true WO2022044951A1 (ja) 2022-03-03

Family

ID=80355191

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/030363 WO2022044951A1 (ja) 2020-08-28 2021-08-19 検査方法

Country Status (4)

Country Link
JP (1) JP7413209B2 (zh)
CN (1) CN115867780A (zh)
TW (1) TW202215016A (zh)
WO (1) WO2022044951A1 (zh)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09229817A (ja) * 1996-02-23 1997-09-05 Matsushita Electric Ind Co Ltd 偏光板の検査方法
JP2007212442A (ja) * 2006-01-11 2007-08-23 Nitto Denko Corp 積層フィルムの製造方法、積層フィルムの欠陥検出方法、積層フィルムの欠陥検出装置、積層フィルム、及び画像表示装置
JP2014059456A (ja) * 2012-09-18 2014-04-03 Dainippon Printing Co Ltd 光学フィルム用転写体、光学フィルム及び画像表示装置
JP2016126005A (ja) * 2014-12-29 2016-07-11 三星ディスプレイ株式會社Ｓａｍｓｕｎｇ Ｄｉｓｐｌａｙ Ｃｏ．，Ｌｔｄ． 表示装置の検査装置及び表示装置の検査方法
JP2019053057A (ja) * 2017-09-13 2019-04-04 住友化学株式会社 欠陥検査装置、欠陥検査方法、円偏光板又は楕円偏光板の製造方法及び位相差板の製造方法
JP2020095247A (ja) * 2018-11-29 2020-06-18 住友化学株式会社 偏光板
JP2020160421A (ja) * 2019-03-22 2020-10-01 住友化学株式会社 検査方法及び検査装置
WO2021124647A1 (ja) * 2019-12-16 2021-06-24 住友化学株式会社 検査方法、検査装置、及び検査システム

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09229817A (ja) * 1996-02-23 1997-09-05 Matsushita Electric Ind Co Ltd 偏光板の検査方法
JP2007212442A (ja) * 2006-01-11 2007-08-23 Nitto Denko Corp 積層フィルムの製造方法、積層フィルムの欠陥検出方法、積層フィルムの欠陥検出装置、積層フィルム、及び画像表示装置
JP2014059456A (ja) * 2012-09-18 2014-04-03 Dainippon Printing Co Ltd 光学フィルム用転写体、光学フィルム及び画像表示装置
JP2016126005A (ja) * 2014-12-29 2016-07-11 三星ディスプレイ株式會社Ｓａｍｓｕｎｇ Ｄｉｓｐｌａｙ Ｃｏ．，Ｌｔｄ． 表示装置の検査装置及び表示装置の検査方法
JP2019053057A (ja) * 2017-09-13 2019-04-04 住友化学株式会社 欠陥検査装置、欠陥検査方法、円偏光板又は楕円偏光板の製造方法及び位相差板の製造方法
JP2020095247A (ja) * 2018-11-29 2020-06-18 住友化学株式会社 偏光板
JP2020160421A (ja) * 2019-03-22 2020-10-01 住友化学株式会社 検査方法及び検査装置
WO2021124647A1 (ja) * 2019-12-16 2021-06-24 住友化学株式会社 検査方法、検査装置、及び検査システム

Also Published As

Publication number Publication date
TW202215016A (zh) 2022-04-16
CN115867780A (zh) 2023-03-28
JP2022039687A (ja) 2022-03-10
JP7413209B2 (ja) 2024-01-15

Similar Documents

Publication Publication Date Title
JP7455527B2 (ja) 検査方法及び検査装置
WO2021176797A1 (ja) 検査方法
WO2021124645A1 (ja) 検査方法、検査装置、及び検査システム
WO2021124647A1 (ja) 検査方法、検査装置、及び検査システム
JP7474569B2 (ja) 検査方法及び検査装置
JP2005009919A (ja) 保護膜付き偏光板の検査装置および検査方法
WO2022044951A1 (ja) 検査方法
WO2022044952A1 (ja) 検査方法
WO2021124646A1 (ja) 検査方法、検査装置、及び検査システム
WO2022092005A1 (ja) 検査方法
WO2022044988A1 (ja) 検査方法
WO2022092006A1 (ja) 検査方法
WO2023189090A1 (ja) 検査方法
CN111721776B (zh) 检查方法及检查装置
WO2023223728A1 (ja) 検査方法
JP2023110350A (ja) 検査方法
TW202413914A (zh) 檢查方法

Legal Events

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

Ref document number: 21861379

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21861379

Country of ref document: EP

Kind code of ref document: A1