WO2015145657A1 - Polarizer and image display device - Google Patents

Polarizer and image display device Download PDF

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Publication number
WO2015145657A1
WO2015145657A1 PCT/JP2014/058844 JP2014058844W WO2015145657A1 WO 2015145657 A1 WO2015145657 A1 WO 2015145657A1 JP 2014058844 W JP2014058844 W JP 2014058844W WO 2015145657 A1 WO2015145657 A1 WO 2015145657A1
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Prior art keywords
polarizer
laser
image display
display device
resin film
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PCT/JP2014/058844
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French (fr)
Japanese (ja)
Inventor
章典 伊▲崎▼
直之 松尾
済木　雄二
清貴 堤
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日東電工株式会社
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Priority to PCT/JP2014/058844 priority Critical patent/WO2015145657A1/en
Publication of WO2015145657A1 publication Critical patent/WO2015145657A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid

Definitions

  • the present invention relates to a polarizer and an image display device.
  • Cameras are usually mounted on image display devices such as mobile phones and notebook personal computers (PCs).
  • image display devices such as mobile phones and notebook personal computers (PCs).
  • PCs notebook personal computers
  • Various studies have been made for the purpose of improving the camera performance of such an image display device (for example, Patent Document 1).
  • Patent Document 1 For example, Patent Document 1
  • smartphones and touch panel type information processing devices further improvement in camera performance is desired.
  • the present invention has been made to solve the above-described conventional problems, and a main object thereof is to provide a polarizer capable of realizing an image display device having excellent camera performance.
  • the inventors focused on a polarizer mounted on an image display device, found that the above object can be achieved by forming a decoloring part in the polarizer and optimizing the characteristics of the decoloring part. It came to be completed.
  • the polarizer of the present invention is composed of a resin film containing a dichroic substance and has a decolorized part that is partially decolored. Birefringence R PVA bleaching unit is 0.035 or less.
  • the decolorization part is formed by irradiating a laser beam including light having a wavelength of 100 pm to 1000 nm.
  • the decoloring unit corresponds to a camera hole unit of an image display device to be mounted.
  • the dichroic material is iodine.
  • the polarizer has a thickness of 30 ⁇ m or less. According to another aspect of the present invention, a method for producing a polarizer is provided.
  • This manufacturing method of a polarizer has a process of forming a decoloring part by irradiating a resin film containing a dichroic substance with a laser beam.
  • the laser light includes light having a wavelength of 100 pm to 1000 nm.
  • the laser is a solid state laser.
  • an image display device is provided.
  • the image display device includes the polarizer.
  • the manufacturing method of the said image display apparatus is provided. This manufacturing method includes a step of irradiating a laser beam onto an image display panel laminated so that a resin film containing a dichroic material is on the surface side to form the decolorized portion.
  • the present invention by forming a decoloring part in a resin film containing a dichroic substance and controlling the birefringence of the decoloring part to a desired range, not only ensuring the transparency of the camera hole part, It is possible to optimize brightness and color at the time of shooting and prevent image distortion, thereby contributing to improvement of camera performance of the obtained image display apparatus.
  • receiving electronic devices such as images and monitors (for example, camera devices having a photographing optical system), but also transmitting electronic devices such as LED lights and infrared sensors, and the naked eye. It is also possible to provide an image display device that ensures the transparency of light and the straightness of light.
  • FIG. 1 is a plan view of a polarizer according to one embodiment of the present invention.
  • FIG. 1 is a plan view of a polarizer according to one embodiment of the invention.
  • the polarizer 1 is made of a resin film and has a decoloring part 2 that is partially decolored. According to such a configuration, compared to a case where a hole is formed in the resin film mechanically (specifically, by a method of mechanically pulling out using an engraving blade punching, a plotter, a water jet, or the like) It is possible to avoid quality problems such as cracks, delamination (delamination), and paste sticking.
  • Birefringence R PVA bleaching unit 2 are 0.035 or less, preferably 0.032 or less, more preferably 0.030 or less.
  • the lower limit of the birefringence R PVA bleaching unit is, for example, 0.010. With such a range birefringence R PVA bleaching unit, not only to impart the desired transparency bleaching unit, in the case of using a bleaching unit as a camera hole portion of the image display device, brightness and color From both viewpoints, it is possible to achieve very good shooting performance.
  • nx is the refractive index in the direction in which the refractive index in the film plane is maximum (that is, the slow axis direction), and ny is the direction that is orthogonal to the slow axis in the film plane (that is, the fast axis direction).
  • the resin film contains a dichroic substance.
  • the dichroic substance include iodine and organic dyes. These may be used alone or in combination of two or more.
  • iodine is used. Iodine has properties suitable for use as a camera hole as a result of the complex with the resin (for example, polyvinyl alcohol-based resin) constituting the resin film disintegrating at an appropriate rate by the predetermined laser irradiation described later.
  • a decolorization part can be formed.
  • any appropriate resin can be used as the resin forming the resin film.
  • PVA resin polyvinyl alcohol resin
  • the complex of the PVA-based resin and iodine is collapsed at an appropriate ratio by irradiation with a predetermined laser, and as a result, a decolorization part having characteristics suitable for use as a camera hole can be formed.
  • the PVA resin include polyvinyl alcohol and ethylene-vinyl alcohol copolymer.
  • Polyvinyl alcohol is obtained by saponifying polyvinyl acetate.
  • the ethylene-vinyl alcohol copolymer can be obtained by saponifying an ethylene-vinyl acetate copolymer.
  • the saponification degree of the PVA resin is usually 85 mol% or more and less than 100 mol%, preferably 95.0 mol% to 99.95 mol%, more preferably 99.0 mol% to 99.93 mol%. is there.
  • the degree of saponification can be determined according to JIS K 6726-1994. By using a PVA-based resin having such a saponification degree, a polarizer having excellent durability can be obtained. If the degree of saponification is too high, there is a risk of gelation.
  • the average degree of polymerization of the PVA resin can be appropriately selected according to the purpose.
  • the average degree of polymerization is usually 1000 to 10,000, preferably 1200 to 4500, and more preferably 1500 to 4300.
  • the average degree of polymerization can be determined according to JIS K 6726-1994.
  • the polarizer (excluding the decoloring part) preferably exhibits absorption dichroism in the wavelength range of 380 nm to 780 nm.
  • the single transmittance (Ts) of the polarizer (excluding the decolorized part) is preferably 40% or more, more preferably 41% or more, still more preferably 42% or more, and particularly preferably 43% or more.
  • the theoretical upper limit of the single transmittance is 50%, and the practical upper limit is 46%.
  • the single transmittance (Ts) is a Y value measured by a JIS Z8701 two-degree field of view (C light source) and corrected for visibility. Can be measured.
  • the degree of polarization of the polarizer (excluding the decolorization part) is preferably 99.8% or more, more preferably 99.9% or more, and further preferably 99.95% or more.
  • the thickness of the polarizer can be set to any appropriate value.
  • the thickness is typically about 1 ⁇ m to 80 ⁇ m, and preferably 30 ⁇ m or less. The thinner the thickness, the better the decolorization part can be formed. For example, in laser light irradiation described later, the absorbance per unit film thickness is high, and a decolorized portion can be formed efficiently.
  • the small-color decoloring part 2 is formed at the center of the upper end of the resin film, but the arrangement, shape, size, etc. of the decoloring part can be designed as appropriate. Preferably, it is designed according to the position, shape, size, etc. of the camera hole part of the mounted image display device. Specifically, it is designed so that the decoloring part does not correspond to the display screen of the mounted image display device.
  • the transmittance of the decolorized part (for example, transmittance measured with light having a wavelength of 550 nm at 23 ° C.) is preferably 46% or more, more preferably 60% or more, still more preferably 75% or more, and particularly preferably 90% or more. It is. With such a transmittance, desired transparency as a decoloring part can be ensured. As a result, when the decoloring part is used as the camera hole part of the image display device, it is possible to prevent an adverse effect on the photographing performance of the camera.
  • the absorbance at a wavelength of 350 nm is preferably 2.5 or less, more preferably 2.3 or less, and even more preferably 2.1 or less.
  • the lower limit of the absorbance is 1.2, for example.
  • the polarizer of the present invention can be used in any appropriate form.
  • a polarizer is used by laminating a protective film on at least one side thereof (as a polarizing film).
  • the material for forming the protective film include cellulose resins such as diacetyl cellulose and triacetyl cellulose, (meth) acrylic resins, cycloolefin resins, olefin resins such as polypropylene, and ester resins such as polyethylene terephthalate resins. , Polyamide resins, polycarbonate resins, copolymer resins thereof, and the like.
  • the surface of the protective film on which the polarizer is not laminated may be subjected to a treatment for the purpose of a hard coat layer, antireflection treatment, diffusion or antiglare as a surface treatment layer.
  • the surface treatment layer is preferably a layer having a low moisture permeability for the purpose of improving the humidification durability of the polarizer.
  • the hard coat treatment is performed for the purpose of preventing scratches on the surface of the polarizing film.
  • the hard coat layer can be formed by, for example, a method of adding a cured film excellent in hardness, slipping properties, etc., to an appropriate ultraviolet curable resin such as acrylic or silicone.
  • the hard coat layer preferably has a pencil hardness of 2H or more.
  • the antireflection treatment is performed for the purpose of preventing the reflection of external light on the surface of the polarizing film, and is based on the interference action of light as disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-248173.
  • Anti-glare treatment is performed for the purpose of preventing external light from being reflected on the surface of the polarizing film and obstructing the visibility of the light transmitted through the polarizing film.
  • a roughening method using a sandblasting method or an embossing method For example, a roughening method using a sandblasting method or an embossing method. Or by applying a fine concavo-convex structure to the surface of the protective film by an appropriate method such as a blending method of transparent fine particles.
  • the antiglare layer may also serve as a diffusion layer (viewing angle expanding function or the like) for diffusing the light transmitted through the polarizing film to expand the viewing angle.
  • the thickness of the protective film is preferably 20 ⁇ m to 100 ⁇ m.
  • the protective film is typically laminated on the polarizer via an adhesive layer (specifically, an adhesive layer or an adhesive layer).
  • the adhesive layer is typically formed of a PVA adhesive.
  • the pressure-sensitive adhesive layer is typically formed of an acrylic pressure-sensitive adhesive.
  • the polarizer is preferably produced by subjecting a resin film containing a dichroic material to a decolorization treatment to form the decolorization part.
  • the resin film containing the dichroic substance is preferably produced by subjecting the resin film to a treatment such as dyeing.
  • the resin film may be a resin layer (PVA resin layer) formed on a resin base material. According to such a form, a thin polarizer (for example, 10 micrometers or less) can be obtained.
  • the dyeing is preferably performed by adsorbing iodine to the resin film.
  • the adsorption method include a method of immersing a resin film in a staining solution containing iodine, a method of applying the staining solution to a resin film, and a method of spraying the staining solution onto the resin film.
  • the resin film is immersed in the dyeing solution. This is because iodine can be adsorbed well.
  • the staining solution is preferably an iodine aqueous solution.
  • the amount of iodine is preferably 0.04 to 5.0 parts by weight per 100 parts by weight of water.
  • an iodide to the aqueous iodine solution.
  • the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide. Etc. Among these, potassium iodide is preferable.
  • the blending amount of iodide is preferably 0.3 to 15 parts by weight with respect to 100 parts by weight of water.
  • the liquid temperature during staining of the staining liquid is preferably 20 ° C. to 50 ° C.
  • the immersion time is preferably 5 seconds to 5 minutes.
  • the resin film may be appropriately subjected to treatment for making a polarizer.
  • the treatment for obtaining a polarizer include stretching treatment, insolubilization treatment, crosslinking treatment, washing treatment, and drying treatment.
  • count, order, etc. of these processes are not specifically limited.
  • any appropriate method can be adopted as the stretching method of the stretching treatment. Specifically, free end stretching or fixed end stretching may be used.
  • the stretching direction can be set as appropriate. In one embodiment, it extends in the longitudinal direction of the long resin film. In this case, typically, a method of stretching through a resin film between rolls having different peripheral speeds is employed. In another embodiment, it extends
  • the stretching method is not particularly limited, and may be wet or dry.
  • the stretching temperature can be appropriately set according to the stretching method, for example.
  • the draw ratio is typically 3 to 7 times. Stretching may be performed in one stage or in multiple stages. When performing in multiple stages, for example, the free end stretching and fixed end stretching may be combined, or the wet stretching and dry stretching may be combined. In addition, when performing by multistep, the said draw ratio is a product of the draw ratio of each step.
  • the resin film is a resin layer (PVA resin layer) formed on a resin base material
  • PVA resin layer resin layer
  • stretching conditions it describes in the patent 4804588 gazette, for example. The description is incorporated herein by reference.
  • the insolubilization treatment and the crosslinking treatment are typically performed by immersing a resin film in an aqueous boric acid solution.
  • the cleaning treatment is typically performed by immersing a resin film in an aqueous potassium iodide solution.
  • the drying temperature in the drying treatment is preferably 30 ° C. to 100 ° C.
  • the decolorization part is preferably formed by irradiating the resin film containing the dichroic substance with laser light. According to laser light irradiation, a decoloring part having a desired shape can be favorably formed at a desired position. More specifically, in recent years, there has been a strong demand for making the image non-display portion of the image display device as small as possible due to design requirements. When the decolorization portion is used as a camera hole, a polarizer is inevitably required. The decolorization part must be formed at the extreme end (for example, the central part of the uppermost end).
  • the laser beam preferably includes light having a wavelength of at least 1500 nm or less. With a laser beam including such a wavelength, a decoloring part can be formed.
  • the laser light more preferably includes light having a wavelength of 100 pm to 1000 nm, further preferably includes light having a wavelength of 400 nm to 900 nm, and particularly preferably includes light having a wavelength of 420 nm to 680 nm.
  • the laser beam has a peak wavelength in the above range.
  • the decoloring part can be formed while achieving surface uniformity. Specifically, the decoloring part can be formed without damaging (for example, thermal deformation) the polarizer peripheral optical member (for example, the protective film).
  • the polarizer can absorb a large amount of light without the peripheral optical member absorbing a large amount of light, and damage to the peripheral optical member can be prevented.
  • a decoloring part can be favorably formed without damaging the resin film itself.
  • the flatness of the obtained image display device image display panel
  • the transmittance of the decoloring part can be achieved satisfactorily.
  • both the complex of the PVA resin and iodine and the iodine complex can be destroyed at an appropriate ratio. It is possible to form a bleaching portion having appropriate characteristics.
  • the laser examples include a solid-state laser such as a YAG laser, a YLF laser, a YVO4 laser, and a titanium sapphire laser, a gas laser including an argon ion laser, and a krypton ion laser, a fiber laser, a semiconductor laser, and a dye laser.
  • a solid laser is used.
  • a short pulse laser (laser that irradiates light having a pulse width of 1 nanosecond or less, such as a picosecond laser or a femtosecond laser) is preferably used.
  • a pulse width of 500 picoseconds or less for example, 10 picoseconds to 50 picoseconds
  • the thermal damage it is possible to satisfactorily suppress the melting of the resin (for example, PVA resin) constituting the resin film. Therefore, a decoloring part having no unevenness and extremely excellent uniformity can be obtained, and as a result, distortion of the image of the camera can be prevented.
  • irradiation with laser light having different wavelengths and / or pulse widths may be combined.
  • the type of laser light to be irradiated and the irradiation order can be appropriately set according to the purpose. For example, by irradiating with a picosecond laser and then with a nanosecond laser, both hue and transparency can be improved as compared with the case of irradiating with a picosecond laser alone.
  • the nanosecond laser preferably has a shorter wavelength (for example, 400 nm to 460 nm) than the picosecond laser.
  • the irradiation condition of the laser beam can be set to any appropriate condition.
  • the pulse energy is preferably 10 ⁇ J to 150 ⁇ J, more preferably 25 ⁇ J to 71 ⁇ J.
  • the scanning speed is preferably 10 mm / second to 10,000 mm / second, and more preferably 100 mm / second to 1000 mm / second.
  • the repetition frequency can be appropriately set according to the set scanning speed and pulse energy so as to realize an optimum bleaching state.
  • the repetition frequency is, for example, 100 Hz to 12480 Hz.
  • the scan pitch is preferably 10 ⁇ m to 50 ⁇ m.
  • the beam shape at the irradiation position of the laser beam can be appropriately set according to the purpose and the desired shape of the decoloring part.
  • the beam shape may be, for example, a circle or a line. Any appropriate means can be adopted as means for setting the beam shape to a predetermined shape.
  • laser irradiation may be performed through a mask having a predetermined opening, or beam shaping may be performed using a diffractive optical element or the like.
  • the focal diameter spot diameter
  • a decoloring part can be formed satisfactorily without damaging the polarizing film peripheral member and the resin film itself.
  • the birefringence RPVA can be satisfactorily achieved.
  • the input energy of the pulse laser is preferably 20000 ⁇ J / mm 2 to 100000 ⁇ J / mm 2 , more preferably 25000 ⁇ J / mm 2 to 75000 ⁇ J / mm 2 . If the input energy is too large, the adhesive or pressure-sensitive adhesive used for attaching the polarizer may burn. If the input energy is too small, the hue of the decolorized part becomes yellow and the transparency may be insufficient.
  • the irradiation mode (scanning mode) of laser light can be set appropriately according to the purpose.
  • the laser beam may be scanned linearly, may be scanned in an S shape, may be scanned in a spiral shape, or a combination thereof.
  • laser light irradiation may be performed with the scanning directions crossed. By performing laser irradiation in this manner, unevenness of the decolorized portion can be reduced and uniformity can be enhanced.
  • the laser beam includes polarized light substantially coaxial with the absorption axis of the resin film (polarizer).
  • polarizer resin film
  • a galvano mirror may be driven to scan and position the laser.
  • a homogenizer (DOE: Diffractive Optical Element) for uniformizing the laser light intensity mainly having a Gaussian distribution may be used for the purpose of obtaining surface uniformity of the decolorized portion.
  • the said decoloring part can be formed favorably, achieving surface uniformity also by irradiating X-rays.
  • the decoloring part can also be formed by a heating means such as a light source (for example, an Xe lamp) that emits light having a wavelength of 100 pm to 1500 nm, a heating plate for barcode printing, and the like.
  • An image display device of the present invention includes the polarizer.
  • the image display device include a liquid crystal display device and an organic EL device.
  • the liquid crystal display device includes a liquid crystal panel including a liquid crystal cell and the polarizer disposed on one side or both sides of the liquid crystal cell.
  • the organic EL device includes an organic EL panel in which the polarizer is disposed on the viewing side.
  • the polarizer is arranged so as to correspond to the camera hole part of the image display device on which the decoloring part is mounted.
  • the image display device includes an image display panel (for example, a liquid crystal panel or an organic EL panel) laminated such that the resin film containing the dichroic material is on the surface side. ) Is irradiated with a laser beam (from the front surface side) to form the decoloring part. According to such a method, positioning of the decoloring part can be facilitated.
  • an image display panel for example, a liquid crystal panel or an organic EL panel
  • Ts Transmissivity
  • Measurement was performed using a microspectroscopic system (Lambda Vision Co., Ltd., LVmicro). Note that Ts is a Y value measured by a two-degree field of view (C light source) of JIS Z8701 and corrected for visibility.
  • Example 1 Using a solid laser (wavelength: 532 nm) under irradiation conditions of a pulse width of 15 picoseconds, a pulse energy of 20 ⁇ J, a scanning speed of 100 mm / sec, a repetition frequency of 6240 Hz, a scanning pitch of 20 ⁇ m, an input energy of 62400 ⁇ J / mm 2 and a spot diameter of 55 ⁇ m.
  • a polarizing film with adhesive having a total thickness of 166 ⁇ m (adhesive layer (thickness 20 ⁇ m) / second protective film (thickness 77 ⁇ m) / polarizer (thickness 22 ⁇ m) / first protective film (thickness 47 ⁇ m))
  • Laser light was irradiated from the first protective film side. In this way, the decoloring part was formed in the polarizing film (polarizer).
  • the first protective film is a TAC film subjected to antireflection treatment
  • the second protective film is a negative biaxial film (thickness 35 ⁇ m) / adhesive layer (thickness 12 ⁇ m) in order from the polarizer side. ) / Has a laminated structure including a positive biaxial film (thickness 30 ⁇ m).
  • Birefringence R PVA unirradiated portion is 0.040
  • the birefringence R PVA of the irradiated part was 0.031.
  • the transmittance of the unirradiated portion was 44.0%
  • the transmittance of the irradiated portion was 66.2%.
  • WYKO manufactured by Bruker AXS Co., Ltd.
  • Example 2 On the viewing side (the first protective film (thickness 47 ⁇ m)) on the polarizing side (adhesive layer (thickness 20 ⁇ m) / second protective film (thickness 57 ⁇ m) / polarizer (thickness 5 ⁇ m) / first protective film (thickness 47 ⁇ m)) with a total thickness of 129 ⁇ m No. 1 protective film side) was irradiated with laser light under the same conditions as in Example 1. In this way, the decoloring part was formed in the polarizing film (polarizer).
  • the first protective film is an acrylic film subjected to antireflection treatment
  • the second protective film is a negative biaxial film (thickness 25 ⁇ m) / adhesive layer (thickness) in order from the polarizer side. 12 [mu] m) / positive biaxial film (thickness 20 [mu] m).
  • Birefringence R PVA unirradiated portion is 0.045
  • the birefringence R PVA of the irradiated part was 0.013
  • the transmittance of the unirradiated portion was 43.7%
  • the transmittance of the irradiated portion was 83.1%.
  • WYKO manufactured by Bruker AXS Co., Ltd.
  • Example 3 After irradiating the same polarizing film as in Example 1 with laser light under the same conditions as in Example 1, using a solid laser (wavelength: 447 nm), the pulse width is 11 nanoseconds, the pulse energy is 30 ⁇ J, and the scanning speed is 100 mm / sec. Further, laser light was additionally irradiated under irradiation conditions of a repetition frequency of 6000 Hz, a scan pitch of 20 ⁇ m, an input energy of 90000 ⁇ J / mm 2 , and a spot diameter of 20 ⁇ m. In this way, the decoloring part was formed in the polarizing film (polarizer).
  • Birefringence R PVA unirradiated portion is 0.045
  • the birefringence R PVA of the irradiated part was 0.011.
  • the transmittance of the unirradiated portion was 43.7%
  • the transmittance of the irradiated portion was 89.1%.
  • WYKO manufactured by Bruker AXS Co., Ltd.
  • Example 1 A part of the polarizing film with glue used in Example 1 was removed by press working with an engraving blade. A crack having a length of 1 mm or more was generated in the peripheral portion that was removed.
  • Example 2 A part of the glue-attached polarizing film used in Example 1 was removed by press working with a heated engraving blade. Although cracks were not confirmed in the peripheral portion that was removed, a step due to thermal deformation occurred, and surface uniformity could not be obtained.
  • Example 3 A CO 2 gas laser (wavelength: 10.6 ⁇ m) was used in the same manner as in Example 1 except that laser light was irradiated under irradiation conditions of a pulse energy of 0.8 mJ, a scanning speed of 300 mm / sec, and a repetition frequency of 3000 Hz. An attempt was made to form a decolorization part.
  • the area irradiated with the laser beam was not decolorized, and both the birefringence RPVA and the transmittance (44.0%) were the same in the unirradiated part and the irradiated part. Moreover, when the surface shape of the irradiation area was confirmed, the remarkable unevenness
  • the polarizer of the present invention is suitably used for a mobile phone such as a smartphone, an image display device with a camera (liquid crystal display device, organic EL device) such as a notebook PC or tablet PC.
  • a mobile phone such as a smartphone
  • an image display device with a camera liquid crystal display device, organic EL device
  • a notebook PC or tablet PC such as a notebook PC or tablet PC.

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Abstract

According to an embodiment of the present invention, a polarizer that can achieve an image display device with superior camera performance is provided. The polarizer according to this embodiment is constituted from a resin film that includes a dichroic substance and has a decolorized part that is partially decolorized. Birefringence (RPVA) of the decolorized part is 0.035 or less. In one embodiment, the decolorized part corresponds to a camera hole part of an image display device whereon the same is mounted.

Description

偏光子および画像表示装置Polarizer and image display device
　本発明は、偏光子および画像表示装置に関する。 The present invention relates to a polarizer and an image display device.
　携帯電話、ノート型パーソナルコンピューター（ＰＣ）等の画像表示装置には、通常、カメラが搭載されている。このような画像表示装置のカメラ性能の向上を目的として、種々の検討がなされている（例えば、特許文献１）。しかし、スマートフォン、タッチパネル式の情報処理装置の急速な普及により、カメラ性能のさらなる向上が望まれている。 Cameras are usually mounted on image display devices such as mobile phones and notebook personal computers (PCs). Various studies have been made for the purpose of improving the camera performance of such an image display device (for example, Patent Document 1). However, with the rapid spread of smartphones and touch panel type information processing devices, further improvement in camera performance is desired.
特開２０１１－８１３１５号公報JP 2011-81315 A
　本発明は上記従来の課題を解決するためになされたものであり、その主たる目的は、カメラ性能に優れた画像表示装置を実現し得る偏光子を提供することにある。 The present invention has been made to solve the above-described conventional problems, and a main object thereof is to provide a polarizer capable of realizing an image display device having excellent camera performance.
　本発明者らは、画像表示装置に搭載される偏光子に着目し、偏光子に脱色部を形成し、当該脱色部の特性を最適化することにより上記目的を達成できることを見出し、本発明を完成するに至った。 The inventors focused on a polarizer mounted on an image display device, found that the above object can be achieved by forming a decoloring part in the polarizer and optimizing the characteristics of the decoloring part. It came to be completed.
　本発明の偏光子は、二色性物質を含む樹脂フィルムから構成され、部分的に脱色された脱色部を有する。脱色部の複屈折ＲＰＶＡは０．０３５以下である。
　１つの実施形態においては、上記脱色部は、１００ｐｍ～１０００ｎｍの波長の光を含むレーザー光を照射して形成される。
　１つの実施形態においては、上記脱色部は、搭載される画像表示装置のカメラホール部に対応する。
　１つの実施形態においては、上記二色性物質はヨウ素である。
　１つの実施形態においては、上記偏光子は厚みが３０μｍ以下である。
　本発明の別の局面によれば、偏光子の製造方法が提供される。この偏光子の製造方法は、二色性物質を含む樹脂フィルムにレーザー光を照射して脱色部を形成する工程を有する。
　１つの実施形態においては、上記レーザー光は、１００ｐｍ～１０００ｎｍの波長の光を含む。
　１つの実施形態においては、上記レーザーは固体レーザーである。
　本発明のさらに別の局面によれば、画像表示装置が提供される。この画像表示装置は、上記偏光子を備える。
　本発明のさらに別の局面によれば、上記画像表示装置の製造方法が提供される。この製造方法は、二色性物質を含む樹脂フィルムが表面側となるように積層された画像表示パネルにレーザー光を照射して、上記脱色部を形成する工程を有する。 The polarizer of the present invention is composed of a resin film containing a dichroic substance and has a decolorized part that is partially decolored. Birefringence R PVA bleaching unit is 0.035 or less.
In one embodiment, the decolorization part is formed by irradiating a laser beam including light having a wavelength of 100 pm to 1000 nm.
In one embodiment, the decoloring unit corresponds to a camera hole unit of an image display device to be mounted.
In one embodiment, the dichroic material is iodine.
In one embodiment, the polarizer has a thickness of 30 μm or less.
According to another aspect of the present invention, a method for producing a polarizer is provided. This manufacturing method of a polarizer has a process of forming a decoloring part by irradiating a resin film containing a dichroic substance with a laser beam.
In one embodiment, the laser light includes light having a wavelength of 100 pm to 1000 nm.
In one embodiment, the laser is a solid state laser.
According to still another aspect of the present invention, an image display device is provided. The image display device includes the polarizer.
According to another situation of this invention, the manufacturing method of the said image display apparatus is provided. This manufacturing method includes a step of irradiating a laser beam onto an image display panel laminated so that a resin film containing a dichroic material is on the surface side to form the decolorized portion.
　本発明によれば、二色性物質を含む樹脂フィルムに脱色部を形成し、当該脱色部の複屈折を所望の範囲に制御することにより、カメラホール部の透過性を確保するのみならず、撮影時の明るさおよび色味を最適化し、かつ、像の歪みを防止して、得られる画像表示装置のカメラ性能の向上に寄与することができる。このように、映像やモニタ等の受信型電子デバイス（例えば、撮影光学系を有するカメラ装置）だけでなく、本発明によれば、ＬＥＤライトや赤外線センサー等の発信型電子デバイスおよび肉眼に対しての透過性および光の直進性を確保する画像表示装置を提供することもできる。 According to the present invention, by forming a decoloring part in a resin film containing a dichroic substance and controlling the birefringence of the decoloring part to a desired range, not only ensuring the transparency of the camera hole part, It is possible to optimize brightness and color at the time of shooting and prevent image distortion, thereby contributing to improvement of camera performance of the obtained image display apparatus. Thus, according to the present invention, not only receiving electronic devices such as images and monitors (for example, camera devices having a photographing optical system), but also transmitting electronic devices such as LED lights and infrared sensors, and the naked eye. It is also possible to provide an image display device that ensures the transparency of light and the straightness of light.
本発明の１つの実施形態による偏光子の平面図である。1 is a plan view of a polarizer according to one embodiment of the present invention. FIG.
　以下、本発明の好ましい実施形態について説明するが、本発明はこれらの実施形態には限定されない。 Hereinafter, preferred embodiments of the present invention will be described, but the present invention is not limited to these embodiments.
Ａ．偏光子
　図１は、本発明の１つの実施形態による偏光子の平面図である。偏光子１は、樹脂フィルムから構成され、部分的に脱色された脱色部２を有する。このような構成によれば、樹脂フィルムに、機械的に（具体的には、彫刻刃打抜き、プロッター、ウォータージェット等を用いて機械的に抜き落とす方法により）穴を形成する場合に比べて、クラック、デラミ（層間剥離）、糊はみ出し等の品質上の問題を回避することができる。 A. Polarizer FIG. 1 is a plan view of a polarizer according to one embodiment of the invention. The polarizer 1 is made of a resin film and has a decoloring part 2 that is partially decolored. According to such a configuration, compared to a case where a hole is formed in the resin film mechanically (specifically, by a method of mechanically pulling out using an engraving blade punching, a plotter, a water jet, or the like) It is possible to avoid quality problems such as cracks, delamination (delamination), and paste sticking.
　脱色部２の複屈折ＲＰＶＡは０．０３５以下であり、好ましくは０．０３２以下であり、より好ましくは０．０３０以下である。脱色部の複屈折ＲＰＶＡの下限は、例えば０．０１０である。脱色部の複屈折ＲＰＶＡがこのような範囲であれば、脱色部に所望の透明性を付与するのみならず、画像表示装置のカメラホール部として脱色部を用いる場合に、明るさおよび色味の両方の観点から非常に優れた撮影性能を実現することができる。このような複屈折は、後述するように、脱色部において樹脂フィルムを構成する樹脂（例えば、ポリビニルアルコール系樹脂）とヨウ素との錯体が適切な割合で崩壊することにより実現され得ると推定される。なお、複屈折ＲＰＶＡは式：ＲＰＶＡ＝ｎｘ－ｎｙで求められる。ここで、ｎｘはフィルム面内の屈折率が最大になる方向（すなわち、遅相軸方向）の屈折率であり、ｎｙはフィルム面内で遅相軸と直交する方向（すなわち、進相軸方向）の屈折率である。 Birefringence R PVA bleaching unit 2 are 0.035 or less, preferably 0.032 or less, more preferably 0.030 or less. The lower limit of the birefringence R PVA bleaching unit is, for example, 0.010. With such a range birefringence R PVA bleaching unit, not only to impart the desired transparency bleaching unit, in the case of using a bleaching unit as a camera hole portion of the image display device, brightness and color From both viewpoints, it is possible to achieve very good shooting performance. As will be described later, it is estimated that such birefringence can be realized when a complex of a resin (for example, a polyvinyl alcohol-based resin) and iodine constituting the resin film in the decolorization part is collapsed at an appropriate ratio. . The birefringence R PVA is obtained by the formula: R PVA = nx−ny. Here, nx is the refractive index in the direction in which the refractive index in the film plane is maximum (that is, the slow axis direction), and ny is the direction that is orthogonal to the slow axis in the film plane (that is, the fast axis direction). ).
　上記樹脂フィルムは、二色性物質を含む。二色性物質としては、例えば、ヨウ素、有機染料等が挙げられる。これらは、単独で、または、二種以上組み合わせて用いられ得る。好ましくは、ヨウ素が用いられる。ヨウ素は、後述する所定のレーザー照射により、樹脂フィルムを構成する樹脂（例えば、ポリビニルアルコール系樹脂）との錯体が適切な割合で崩壊し、その結果、カメラホールとして使用するに適切な特性を有する脱色部を形成することができる。 The resin film contains a dichroic substance. Examples of the dichroic substance include iodine and organic dyes. These may be used alone or in combination of two or more. Preferably, iodine is used. Iodine has properties suitable for use as a camera hole as a result of the complex with the resin (for example, polyvinyl alcohol-based resin) constituting the resin film disintegrating at an appropriate rate by the predetermined laser irradiation described later. A decolorization part can be formed.
　上記樹脂フィルムを形成する樹脂としては、任意の適切な樹脂が用いられ得る。好ましくは、ポリビニルアルコール系樹脂（以下、「ＰＶＡ系樹脂」と称する）が用いられる。上記のとおり、ＰＶＡ系樹脂とヨウ素との錯体は、所定のレーザー照射により適切な割合で崩壊し、その結果、カメラホールとして使用するに適切な特性を有する脱色部を形成することができる。ＰＶＡ系樹脂としては、例えば、ポリビニルアルコール、エチレン－ビニルアルコール共重合体が挙げられる。ポリビニルアルコールは、ポリ酢酸ビニルをケン化することにより得られる。エチレン－ビニルアルコール共重合体は、エチレン－酢酸ビニル共重合体をケン化することにより得られる。ＰＶＡ系樹脂のケン化度は、通常８５モル％以上１００モル％未満であり、好ましくは９５．０モル％～９９．９５モル％、さらに好ましくは９９．０モル％～９９．９３モル％である。ケン化度は、ＪＩＳ　Ｋ　６７２６－１９９４に準じて求めることができる。このようなケン化度のＰＶＡ系樹脂を用いることによって、耐久性に優れた偏光子を得ることができる。ケン化度が高すぎる場合には、ゲル化してしまうおそれがある。 Any appropriate resin can be used as the resin forming the resin film. Preferably, polyvinyl alcohol resin (hereinafter referred to as “PVA resin”) is used. As described above, the complex of the PVA-based resin and iodine is collapsed at an appropriate ratio by irradiation with a predetermined laser, and as a result, a decolorization part having characteristics suitable for use as a camera hole can be formed. Examples of the PVA resin include polyvinyl alcohol and ethylene-vinyl alcohol copolymer. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. The ethylene-vinyl alcohol copolymer can be obtained by saponifying an ethylene-vinyl acetate copolymer. The saponification degree of the PVA resin is usually 85 mol% or more and less than 100 mol%, preferably 95.0 mol% to 99.95 mol%, more preferably 99.0 mol% to 99.93 mol%. is there. The degree of saponification can be determined according to JIS K 6726-1994. By using a PVA-based resin having such a saponification degree, a polarizer having excellent durability can be obtained. If the degree of saponification is too high, there is a risk of gelation.
　ＰＶＡ系樹脂の平均重合度は、目的に応じて適切に選択され得る。平均重合度は、通常１０００～１００００であり、好ましくは１２００～４５００、さらに好ましくは１５００～４３００である。なお、平均重合度は、ＪＩＳ　Ｋ　６７２６－１９９４に準じて求めることができる。 The average degree of polymerization of the PVA resin can be appropriately selected according to the purpose. The average degree of polymerization is usually 1000 to 10,000, preferably 1200 to 4500, and more preferably 1500 to 4300. The average degree of polymerization can be determined according to JIS K 6726-1994.
　偏光子（脱色部を除く）は、好ましくは、波長３８０ｎｍ～７８０ｎｍの範囲で吸収二色性を示す。偏光子（脱色部を除く）の単体透過率（Ｔｓ）は、好ましくは４０％以上、より好ましくは４１％以上、さらに好ましくは４２％以上、特に好ましくは４３％以上である。なお、単体透過率の理論上の上限は５０％であり、実用的な上限は４６％である。また、単体透過率（Ｔｓ）は、ＪＩＳ　Ｚ８７０１の２度視野（Ｃ光源）により測定して視感度補正を行なったＹ値であり、例えば、顕微分光システム（ラムダビジョン製、ＬＶｍｉｃｒｏ）を用いて測定することができる。偏光子（脱色部を除く）の偏光度は、好ましくは９９．８％以上、より好ましくは９９．９％以上、さらに好ましくは９９．９５％以上である。 The polarizer (excluding the decoloring part) preferably exhibits absorption dichroism in the wavelength range of 380 nm to 780 nm. The single transmittance (Ts) of the polarizer (excluding the decolorized part) is preferably 40% or more, more preferably 41% or more, still more preferably 42% or more, and particularly preferably 43% or more. The theoretical upper limit of the single transmittance is 50%, and the practical upper limit is 46%. Further, the single transmittance (Ts) is a Y value measured by a JIS Z8701 two-degree field of view (C light source) and corrected for visibility. Can be measured. The degree of polarization of the polarizer (excluding the decolorization part) is preferably 99.8% or more, more preferably 99.9% or more, and further preferably 99.95% or more.
　偏光子の厚みは、任意の適切な値に設定され得る。厚みは、代表的には１μｍ～８０μｍ程度であり、好ましくは３０μｍ以下である。厚みが薄いほど、脱色部が良好に形成され得る。例えば、後述するレーザー光照射において、単位膜厚当たりの吸光度が高く、効率良く脱色部を形成することができる。 The thickness of the polarizer can be set to any appropriate value. The thickness is typically about 1 μm to 80 μm, and preferably 30 μm or less. The thinner the thickness, the better the decolorization part can be formed. For example, in laser light irradiation described later, the absorbance per unit film thickness is high, and a decolorized portion can be formed efficiently.
　図示例では、小円形の脱色部２が樹脂フィルムの上端部中央部に形成されているが、脱色部の配置、形状、サイズ等は、適宜、設計され得る。好ましくは、搭載される画像表示装置のカメラホール部の位置、形状、サイズ等に応じて設計される。具体的には、搭載される画像表示装置の表示画面に脱色部が対応しないように設計される。 In the illustrated example, the small-color decoloring part 2 is formed at the center of the upper end of the resin film, but the arrangement, shape, size, etc. of the decoloring part can be designed as appropriate. Preferably, it is designed according to the position, shape, size, etc. of the camera hole part of the mounted image display device. Specifically, it is designed so that the decoloring part does not correspond to the display screen of the mounted image display device.
　上記脱色部の透過率（例えば、２３℃における波長５５０ｎｍの光で測定した透過率）は、好ましくは４６％以上、より好ましくは６０％以上、さらに好ましくは７５％以上、特に好ましくは９０％以上である。このような透過率であれば、脱色部としての所望の透明性を確保することができる。その結果、画像表示装置のカメラホール部として脱色部を使用した場合に、カメラの撮影性能に対する悪影響を防止することができる。 The transmittance of the decolorized part (for example, transmittance measured with light having a wavelength of 550 nm at 23 ° C.) is preferably 46% or more, more preferably 60% or more, still more preferably 75% or more, and particularly preferably 90% or more. It is. With such a transmittance, desired transparency as a decoloring part can be ensured. As a result, when the decoloring part is used as the camera hole part of the image display device, it is possible to prevent an adverse effect on the photographing performance of the camera.
　上記脱色部は、波長３５０ｎｍにおける吸光度が、好ましくは２．５以下であり、より好ましくは２．３以下であり、さらに好ましくは２．１以下である。吸光度の下限は、例えば１．２である。脱色部がこのような吸光度を有することにより、画像表示装置のカメラホール部として脱色部を用いる場合に、明るさおよび色味の両方の観点から非常に優れた撮影性能を実現することができる。この効果は、上記の複屈折による効果と相乗的に発揮され得る。脱色部においては、上記のとおり、ＰＶＡ系樹脂とヨウ素との錯体が適切な割合で崩壊することにより、このような効果が実現されていると推定されるところ、さらに、ヨウ素錯体も適切な割合で崩壊することにより、上記所望の吸光度が実現され、相乗的な効果が発揮され得る。 The absorbance at a wavelength of 350 nm is preferably 2.5 or less, more preferably 2.3 or less, and even more preferably 2.1 or less. The lower limit of the absorbance is 1.2, for example. When the decoloring part has such absorbance, when the decoloring part is used as the camera hole part of the image display device, it is possible to realize a very excellent photographing performance from the viewpoint of both brightness and color. This effect can be exhibited synergistically with the above-described effect due to birefringence. In the decolorization part, as described above, it is estimated that such an effect is realized by the decomposition of the complex of the PVA resin and iodine at an appropriate ratio. Furthermore, the iodine complex is also in an appropriate ratio. The above-mentioned desired absorbance can be realized by collapsing with, and a synergistic effect can be exhibited.
　本発明の偏光子は、任意の適切な形態で使用され得る。代表的には、偏光子は、少なくともその片側に保護フィルムを積層させて（偏光フィルムとして）使用される。保護フィルムの形成材料としては、例えば、ジアセチルセルロース、トリアセチルセルロース等のセルロース系樹脂、（メタ）アクリル系樹脂、シクロオレフィン系樹脂、ポリプロピレン等のオレフィン系樹脂、ポリエチレンテレフタレート系樹脂等のエステル系樹脂、ポリアミド系樹脂、ポリカーボネート系樹脂、これらの共重体樹脂等が挙げられる。 The polarizer of the present invention can be used in any appropriate form. Typically, a polarizer is used by laminating a protective film on at least one side thereof (as a polarizing film). Examples of the material for forming the protective film include cellulose resins such as diacetyl cellulose and triacetyl cellulose, (meth) acrylic resins, cycloolefin resins, olefin resins such as polypropylene, and ester resins such as polyethylene terephthalate resins. , Polyamide resins, polycarbonate resins, copolymer resins thereof, and the like.
　保護フィルムの偏光子を積層させない面には、表面処理層として、ハードコート層や反射防止処理、拡散ないしアンチグレアを目的とした処理が施されていてもよい。表面処理層は、例えば、偏光子の加湿耐久性を向上させる目的で透湿度の低い層であることが好ましい。ハードコート処理は、偏光フィルム表面の傷付き防止などを目的に施されるものである。ハードコート層は、例えば、アクリル系、シリコーン系などの適宜な紫外線硬化型樹脂による硬度や滑り特性等に優れる硬化皮膜を表面に付加する方式などにて形成することができる。ハードコート層としては、鉛筆硬度が２Ｈ以上であることが好ましい。反射防止処理は、偏光フィルム表面での外光の反射防止を目的に施されるものであり、従来に準じた、例えば、特開２００５－２４８１７３号公報に開示されるような光の干渉作用による反射光の打ち消し効果を利用して反射を防止する薄層タイプや、特開２０１１－２７５９号公報に開示されるような表面に微細構造を付与することにより低反射率を発現させる構造タイプなどの低反射層の形成により達成することができる。アンチグレア処理は、偏光フィルム表面で外光が反射して偏光フィルム透過光の視認を阻害することの防止等を目的に施されるものであり、例えば、サンドブラスト方式やエンボス加工方式による粗面化方式や透明微粒子の配合方式などの適宜な方式にて保護フィルムの表面に微細凹凸構造を付与することにより施される。アンチグレア層は、偏光フィルム透過光を拡散して視角などを拡大するための拡散層（視角拡大機能など）を兼ねるものであってもよい。 The surface of the protective film on which the polarizer is not laminated may be subjected to a treatment for the purpose of a hard coat layer, antireflection treatment, diffusion or antiglare as a surface treatment layer. For example, the surface treatment layer is preferably a layer having a low moisture permeability for the purpose of improving the humidification durability of the polarizer. The hard coat treatment is performed for the purpose of preventing scratches on the surface of the polarizing film. The hard coat layer can be formed by, for example, a method of adding a cured film excellent in hardness, slipping properties, etc., to an appropriate ultraviolet curable resin such as acrylic or silicone. The hard coat layer preferably has a pencil hardness of 2H or more. The antireflection treatment is performed for the purpose of preventing the reflection of external light on the surface of the polarizing film, and is based on the interference action of light as disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-248173. Such as a thin layer type that prevents reflection by utilizing the cancellation effect of reflected light, and a structure type that exhibits low reflectivity by imparting a fine structure to the surface as disclosed in JP 2011-2759 A, etc. This can be achieved by forming a low reflective layer. Anti-glare treatment is performed for the purpose of preventing external light from being reflected on the surface of the polarizing film and obstructing the visibility of the light transmitted through the polarizing film. For example, a roughening method using a sandblasting method or an embossing method. Or by applying a fine concavo-convex structure to the surface of the protective film by an appropriate method such as a blending method of transparent fine particles. The antiglare layer may also serve as a diffusion layer (viewing angle expanding function or the like) for diffusing the light transmitted through the polarizing film to expand the viewing angle.
　保護フィルムの厚みは、好ましくは２０μｍ～１００μｍである。保護フィルムは、代表的には、接着層（具体的には、接着剤層、粘着剤層）を介して偏光子に積層される。接着剤層は、代表的にはＰＶＡ系接着剤で形成される。粘着剤層は、代表的にはアクリル系粘着剤で形成される。 The thickness of the protective film is preferably 20 μm to 100 μm. The protective film is typically laminated on the polarizer via an adhesive layer (specifically, an adhesive layer or an adhesive layer). The adhesive layer is typically formed of a PVA adhesive. The pressure-sensitive adhesive layer is typically formed of an acrylic pressure-sensitive adhesive.
Ｂ．偏光子の製造方法
　上記偏光子は、好ましくは、二色性物質を含む樹脂フィルムに脱色処理を施して上記脱色部を形成することにより製造される。 B. Method for Producing Polarizer The polarizer is preferably produced by subjecting a resin film containing a dichroic material to a decolorization treatment to form the decolorization part.
　上記二色性物質を含む樹脂フィルムは、好ましくは、上記樹脂フィルムに染色等の処理を施すことにより製造される。なお、樹脂フィルムは、樹脂基材上に形成された樹脂層（ＰＶＡ系樹脂層）であってもよい。このような形態によれば、厚みの薄い（例えば、１０μｍ以下）偏光子を得ることができる。 The resin film containing the dichroic substance is preferably produced by subjecting the resin film to a treatment such as dyeing. The resin film may be a resin layer (PVA resin layer) formed on a resin base material. According to such a form, a thin polarizer (for example, 10 micrometers or less) can be obtained.
Ｂ－１．染色
　上記染色は、好ましくは、樹脂フィルムにヨウ素を吸着させることにより行う。当該吸着方法としては、例えば、ヨウ素を含む染色液に樹脂フィルムを浸漬させる方法、樹脂フィルムに当該染色液を塗工する方法、当該染色液を樹脂フィルムに噴霧する方法等が挙げられる。好ましくは、染色液に樹脂フィルムを浸漬させる方法である。ヨウ素が良好に吸着し得るからである。 B-1. Dyeing The dyeing is preferably performed by adsorbing iodine to the resin film. Examples of the adsorption method include a method of immersing a resin film in a staining solution containing iodine, a method of applying the staining solution to a resin film, and a method of spraying the staining solution onto the resin film. Preferably, the resin film is immersed in the dyeing solution. This is because iodine can be adsorbed well.
　上記染色液は、好ましくは、ヨウ素水溶液である。ヨウ素の配合量は、水１００重量部に対して、好ましくは０．０４重量部～５．０重量部である。ヨウ素の水に対する溶解度を高めるため、ヨウ素水溶液にヨウ化物を配合することが好ましい。ヨウ化物としては、例えば、ヨウ化カリウム、ヨウ化リチウム、ヨウ化ナトリウム、ヨウ化亜鉛、ヨウ化アルミニウム、ヨウ化鉛、ヨウ化銅、ヨウ化バリウム、ヨウ化カルシウム、ヨウ化錫、ヨウ化チタン等が挙げられる。これらの中でも、好ましくは、ヨウ化カリウムである。ヨウ化物の配合量は、水１００重量部に対して、好ましくは０．３重量部～１５重量部である。 The staining solution is preferably an iodine aqueous solution. The amount of iodine is preferably 0.04 to 5.0 parts by weight per 100 parts by weight of water. In order to increase the solubility of iodine in water, it is preferable to add an iodide to the aqueous iodine solution. Examples of the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide. Etc. Among these, potassium iodide is preferable. The blending amount of iodide is preferably 0.3 to 15 parts by weight with respect to 100 parts by weight of water.
　染色液の染色時の液温は、好ましくは２０℃～５０℃である。染色液にＰＶＡ系樹脂膜を浸漬させる場合、浸漬時間は、好ましくは５秒～５分である。 The liquid temperature during staining of the staining liquid is preferably 20 ° C. to 50 ° C. When the PVA resin film is immersed in the staining solution, the immersion time is preferably 5 seconds to 5 minutes.
Ｂ－２．その他の処理
　樹脂フィルムは、染色以外に、偏光子とするための処理が、適宜施され得る。偏光子とするための処理としては、例えば、延伸処理、不溶化処理、架橋処理、洗浄処理、乾燥処理等が挙げられる。なお、これらの処理の回数、順序等は、特に限定されない。 B-2. Other treatments In addition to dyeing, the resin film may be appropriately subjected to treatment for making a polarizer. Examples of the treatment for obtaining a polarizer include stretching treatment, insolubilization treatment, crosslinking treatment, washing treatment, and drying treatment. In addition, the frequency | count, order, etc. of these processes are not specifically limited.
　上記延伸処理の延伸方法としては、任意の適切な方法が採用され得る。具体的には、自由端延伸でもよいし、固定端延伸でもよい。 Any appropriate method can be adopted as the stretching method of the stretching treatment. Specifically, free end stretching or fixed end stretching may be used.
　延伸方向は、適宜、設定され得る。１つの実施形態においては、長尺状の樹脂フィルムの長手方向に延伸する。この場合、代表的には、周速の異なるロール間に樹脂フィルムを通して延伸する方法が採用される。別の実施形態においては、長尺状の樹脂フィルムの幅方向に延伸する。この場合、代表的には、テンター延伸機を用いて延伸する方法が採用される。なお、延伸方向は、得られる偏光子の吸収軸方向に対応し得る。 The stretching direction can be set as appropriate. In one embodiment, it extends in the longitudinal direction of the long resin film. In this case, typically, a method of stretching through a resin film between rolls having different peripheral speeds is employed. In another embodiment, it extends | stretches in the width direction of an elongate resin film. In this case, typically, a method of stretching using a tenter stretching machine is employed. The stretching direction can correspond to the absorption axis direction of the obtained polarizer.
　延伸方式は、特に限定されず、湿式でもよいし、乾式でもよい。延伸温度は、例えば、延伸方式に応じて適宜設定され得る。 The stretching method is not particularly limited, and may be wet or dry. The stretching temperature can be appropriately set according to the stretching method, for example.
　延伸倍率は、代表的には３倍～７倍である。延伸は、一段階で行ってもよいし、多段階で行ってもよい。多段階で行う場合、例えば、上記自由端延伸と固定端延伸とを組み合わせてもよいし、上記湿式延伸と乾式延伸とを組み合わせてもよい。なお、多段階で行う場合、上記延伸倍率は、各段階の延伸倍率の積である。 The draw ratio is typically 3 to 7 times. Stretching may be performed in one stage or in multiple stages. When performing in multiple stages, for example, the free end stretching and fixed end stretching may be combined, or the wet stretching and dry stretching may be combined. In addition, when performing by multistep, the said draw ratio is a product of the draw ratio of each step.
　上述のように、樹脂フィルムが、樹脂基材上に形成された樹脂層（ＰＶＡ系樹脂層）である場合、乾式延伸と湿式延伸とを組み合わせることが好ましい。より具体的には、樹脂基材と樹脂層（樹脂フィルム）との積層体を乾式延伸し、さらに、ホウ酸水溶液中で湿式延伸することが好ましい。なお、樹脂基材の具体的な例および詳細な延伸条件としては、例えば、特許第４８０４５８８号公報に記載されている。当該記載は、本明細書に参考として援用される。 As described above, when the resin film is a resin layer (PVA resin layer) formed on a resin base material, it is preferable to combine dry stretching and wet stretching. More specifically, it is preferable to dry-stretch a laminate of a resin base material and a resin layer (resin film), and further wet-stretch in a boric acid aqueous solution. In addition, as a specific example of a resin base material and detailed extending | stretching conditions, it describes in the patent 4804588 gazette, for example. The description is incorporated herein by reference.
　上記不溶化処理および架橋処理は、代表的には、ホウ酸水溶液に樹脂フィルムを浸漬させることにより行う。上記洗浄処理は、代表的には、ヨウ化カリウム水溶液に樹脂フィルムを浸漬させることにより行う。上記乾燥処理における乾燥温度は、好ましくは３０℃～１００℃である。 The insolubilization treatment and the crosslinking treatment are typically performed by immersing a resin film in an aqueous boric acid solution. The cleaning treatment is typically performed by immersing a resin film in an aqueous potassium iodide solution. The drying temperature in the drying treatment is preferably 30 ° C. to 100 ° C.
Ｂ－３．脱色
　上記脱色部は、好ましくは、上記二色性物質を含む樹脂フィルムにレーザー光を照射することにより形成される。レーザー光照射によれば、所望の位置に所望の形状を有する脱色部を良好に形成し得る。より詳細には、近年、デザイン上の要請から画像表示装置の画像非表示部をできるだけ小さくすることが強く求められているところ、脱色部をカメラホールとして使用する場合には、必然的に偏光子の最端部（例えば、最上端中央部）に脱色部を形成しなければならない。この場合、カメラホールとして脱色部の代わりに機械的に穴を形成しようとすると、偏光フィルムの端部を切り欠いてしまう場合がある。結果として、機械的強度の観点からも商品価値の観点からも偏光フィルムとして使用不可能となってしまう場合がある。レーザー光照射によれば、そのような不具合を防止することができる。また、上述のように、樹脂フィルムに保護フィルムが積層された状態であっても、脱色部を形成し得る。さらに、量産性にも優れ得る。 B-3. Decolorization The decolorization part is preferably formed by irradiating the resin film containing the dichroic substance with laser light. According to laser light irradiation, a decoloring part having a desired shape can be favorably formed at a desired position. More specifically, in recent years, there has been a strong demand for making the image non-display portion of the image display device as small as possible due to design requirements. When the decolorization portion is used as a camera hole, a polarizer is inevitably required. The decolorization part must be formed at the extreme end (for example, the central part of the uppermost end). In this case, if a hole is mechanically formed as a camera hole instead of the decoloring portion, the end portion of the polarizing film may be cut out. As a result, it may be impossible to use as a polarizing film from the viewpoint of mechanical strength and commercial value. Such inconvenience can be prevented by laser light irradiation. Further, as described above, even in a state where the protective film is laminated on the resin film, the decolorized portion can be formed. Furthermore, it can be excellent in mass productivity.
　上記レーザー光は、好ましくは、少なくとも１５００ｎｍ以下の波長の光を含む。このような波長を含むレーザー光によれば、脱色部を形成し得る。レーザー光は、より好ましくは１００ｐｍ～１０００ｎｍの波長の光を含み、さらに好ましくは４００ｎｍ～９００ｎｍの波長の光を含み、特に好ましくは４２０ｎｍ～６８０ｎｍの波長の光を含む。１つの実施形態においては、レーザー光は、上記のような範囲にピーク波長を有する。このような波長を含むレーザー光によれば、面均一性を達成しながら、脱色部を形成することができる。具体的には、偏光子周辺光学部材（例えば、上記保護フィルム）にダメージ（例えば、熱変形）を与えることなく、脱色部を形成することができる。より詳細には、上記のような波長を有するレーザー光であれば、偏光子とその周辺光学部材との吸光度の差が大きくなる。したがって、周辺光学部材が光を大量に吸収することなく偏光子が大量の光を吸収し、周辺光学部材へのダメージを防止することができる。また、樹脂フィルム自体にダメージを与えることなく、良好に脱色部を形成することができる。その結果、得られる画像表示装置（画像表示パネル）の平面性を確保し、良好なモジュール設計を達成することができる。さらに、上記波長を含むレーザー光によれば、上記脱色部の透過率を良好に達成し得る。加えて、このような波長を含むレーザー光によれば、ＰＶＡ系樹脂とヨウ素との錯体およびヨウ素錯体のいずれをも適切な割合で崩壊させることができるので、結果として、カメラホールとして使用するに適切な特性を有する脱色部を形成することができる。 The laser beam preferably includes light having a wavelength of at least 1500 nm or less. With a laser beam including such a wavelength, a decoloring part can be formed. The laser light more preferably includes light having a wavelength of 100 pm to 1000 nm, further preferably includes light having a wavelength of 400 nm to 900 nm, and particularly preferably includes light having a wavelength of 420 nm to 680 nm. In one embodiment, the laser beam has a peak wavelength in the above range. According to the laser light including such a wavelength, the decoloring part can be formed while achieving surface uniformity. Specifically, the decoloring part can be formed without damaging (for example, thermal deformation) the polarizer peripheral optical member (for example, the protective film). More specifically, if the laser light has the wavelength as described above, the difference in absorbance between the polarizer and the peripheral optical member becomes large. Accordingly, the polarizer can absorb a large amount of light without the peripheral optical member absorbing a large amount of light, and damage to the peripheral optical member can be prevented. Moreover, a decoloring part can be favorably formed without damaging the resin film itself. As a result, the flatness of the obtained image display device (image display panel) can be ensured, and a good module design can be achieved. Furthermore, according to the laser beam including the wavelength, the transmittance of the decoloring part can be achieved satisfactorily. In addition, according to the laser light including such a wavelength, both the complex of the PVA resin and iodine and the iodine complex can be destroyed at an appropriate ratio. It is possible to form a bleaching portion having appropriate characteristics.
　上記レーザーとしては、例えば、ＹＡＧレーザー、ＹＬＦレーザー、ＹＶＯ４レーザー、チタンサファイアレーザー等の固体レーザー、アルゴンイオンレーザー、クリプトンイオンレーザーを含むガスレーザー、ファイバーレーザー、半導体レーザー、色素レーザーが挙げられる。好ましくは、固体レーザーが用いられる。 Examples of the laser include a solid-state laser such as a YAG laser, a YLF laser, a YVO4 laser, and a titanium sapphire laser, a gas laser including an argon ion laser, and a krypton ion laser, a fiber laser, a semiconductor laser, and a dye laser. Preferably, a solid laser is used.
　上記レーザーとしては、好ましくは、短パルスレーザー（１ナノ秒以下のパルス幅を有する光を照射するレーザー、例えば、ピコ秒レーザーまたはフェムト秒レーザー等）が用いられる。樹脂フィルムへの熱ダメージを抑制する目的では、５００ピコ秒以下（例えば、１０ピコ秒～５０ピコ秒）のパルス幅が特に好ましい。熱ダメージを抑制することにより、樹脂フィルムを構成する樹脂（例えば、ＰＶＡ系樹脂）の溶融を良好に抑制することができる。したがって、ムラがなく、非常に優れた均一性を有する脱色部が得られ、結果として、カメラの像の歪みが防止され得る。１つの実施形態においては、波長および／またはパルス幅の異なるレーザー光の照射を組み合わせてもよい。照射するレーザー光の種類および照射順序は、目的に応じて適切に設定され得る。例えば、ピコ秒レーザーを照射した後、ナノ秒レーザーを照射することにより、ピコ秒レーザーを単独で照射する場合に比べて色相および透明性のいずれもが改善され得る。この場合、ナノ秒レーザーは、ピコ秒レーザーよりも短波長（例えば、４００ｎｍ～４６０ｎｍ）であることが好ましい。 As the laser, a short pulse laser (laser that irradiates light having a pulse width of 1 nanosecond or less, such as a picosecond laser or a femtosecond laser) is preferably used. In order to suppress thermal damage to the resin film, a pulse width of 500 picoseconds or less (for example, 10 picoseconds to 50 picoseconds) is particularly preferable. By suppressing the thermal damage, it is possible to satisfactorily suppress the melting of the resin (for example, PVA resin) constituting the resin film. Therefore, a decoloring part having no unevenness and extremely excellent uniformity can be obtained, and as a result, distortion of the image of the camera can be prevented. In one embodiment, irradiation with laser light having different wavelengths and / or pulse widths may be combined. The type of laser light to be irradiated and the irradiation order can be appropriately set according to the purpose. For example, by irradiating with a picosecond laser and then with a nanosecond laser, both hue and transparency can be improved as compared with the case of irradiating with a picosecond laser alone. In this case, the nanosecond laser preferably has a shorter wavelength (for example, 400 nm to 460 nm) than the picosecond laser.
　レーザー光の照射条件は、任意の適切な条件に設定され得る。例えば、固体レーザー（ＹＶＯ４レーザー）を用いる場合、パルスエネルギーは、好ましくは１０μＪ～１５０μＪ、より好ましくは２５μＪ～７１μＪである。スキャン速度は、好ましくは１０ｍｍ／秒～１００００ｍｍ／秒であり、より好ましくは１００ｍｍ／秒～１０００ｍｍ／秒である。繰返し周波数は、設定したスキャン速度およびパルスエネルギーに応じて、最適な脱色状態を実現し得るよう適切に設定され得る。繰返し周波数は、例えば１００Ｈｚ～１２４８０Ｈｚである。スキャンピッチは、好ましくは１０μｍ～５０μｍである。レーザー光の照射位置におけるビーム形状は、目的や脱色部の所望の形状に応じて適切に設定され得る。当該ビーム形状は、例えば、円形であってもよく、ライン状であってもよい。ビーム形状を所定の形状とする手段としては、任意の適切な手段が採用され得る。例えば、所定の開口部を有するマスクを介してレーザー照射してもよく、回折光学素子等を用いてビーム整形してもよい。例えばビーム形状が円形である場合には、焦点径（スポット径）は、好ましくは５０μｍ～６０μｍである。上記のような条件によれば、偏光フィルム周辺部材や樹脂フィルム自体にダメージを与えることなく、良好に脱色部を形成することができる。また、上記複屈折ＲＰＶＡを良好に達成し得る。さらに、パルスレーザーの投入エネルギーは、好ましくは２００００μＪ／ｍｍ２～１０００００μＪ／ｍｍ２であり、より好ましくは２５０００μＪ／ｍｍ２～７５０００μＪ／ｍｍ２である。投入エネルギーが大きすぎると、偏光子の貼り合わせに使用される接着剤または粘着剤が焦げる場合がある。投入エネルギーが小さすぎると、脱色部の色相が黄色くなってしまい、透明性が不十分となる場合がある。なお、投入エネルギーＥ（μＪ／ｍｍ２）は下記の式から求められる。
　　　　Ｅ＝（ｅ×Ｍ）／（Ｖ×ｐ）
　　　　　　　　ｅ：パルスエネルギー（Ｊ）
　　　　　　　　Ｍ：繰り返し周波数（Ｈｚ）
　　　　　　　　Ｖ：スキャン速度（ｍｍ／秒）
　　　　　　　　ｐ：スキャンピッチ（ｍｍ） The irradiation condition of the laser beam can be set to any appropriate condition. For example, when a solid laser (YVO4 laser) is used, the pulse energy is preferably 10 μJ to 150 μJ, more preferably 25 μJ to 71 μJ. The scanning speed is preferably 10 mm / second to 10,000 mm / second, and more preferably 100 mm / second to 1000 mm / second. The repetition frequency can be appropriately set according to the set scanning speed and pulse energy so as to realize an optimum bleaching state. The repetition frequency is, for example, 100 Hz to 12480 Hz. The scan pitch is preferably 10 μm to 50 μm. The beam shape at the irradiation position of the laser beam can be appropriately set according to the purpose and the desired shape of the decoloring part. The beam shape may be, for example, a circle or a line. Any appropriate means can be adopted as means for setting the beam shape to a predetermined shape. For example, laser irradiation may be performed through a mask having a predetermined opening, or beam shaping may be performed using a diffractive optical element or the like. For example, when the beam shape is circular, the focal diameter (spot diameter) is preferably 50 μm to 60 μm. According to the above conditions, a decoloring part can be formed satisfactorily without damaging the polarizing film peripheral member and the resin film itself. Moreover, the birefringence RPVA can be satisfactorily achieved. Further, the input energy of the pulse laser is preferably 20000 μJ / mm 2 to 100000 μJ / mm 2 , more preferably 25000 μJ / mm 2 to 75000 μJ / mm 2 . If the input energy is too large, the adhesive or pressure-sensitive adhesive used for attaching the polarizer may burn. If the input energy is too small, the hue of the decolorized part becomes yellow and the transparency may be insufficient. The input energy E (μJ / mm 2 ) is obtained from the following formula.
E = (e × M) / (V × p)
e: Pulse energy (J)
M: Repetition frequency (Hz)
V: Scanning speed (mm / sec)
p: Scan pitch (mm)
　レーザー光の照射形態（走査様式）は、目的に応じて適切に設定され得る。レーザー光は、例えば、直線状に走査されてもよく、Ｓ字状に走査されてもよく、渦巻き状に走査されてもよく、これらを組み合わせてもよい。１つの実施形態においては、レーザー光の照射は、走査方向を交差させて行われ得る。このようにしてレーザー照射を行うことにより、脱色部のムラを低減し、均一性を高めることができる。 The irradiation mode (scanning mode) of laser light can be set appropriately according to the purpose. For example, the laser beam may be scanned linearly, may be scanned in an S shape, may be scanned in a spiral shape, or a combination thereof. In one embodiment, laser light irradiation may be performed with the scanning directions crossed. By performing laser irradiation in this manner, unevenness of the decolorized portion can be reduced and uniformity can be enhanced.
　好ましくは、上記レーザー光は、上記樹脂フィルム（偏光子）の吸収軸と略同軸の偏光を含む。このようなレーザー光によれば、偏光子とその周辺光学部材との吸光度の差をより増大し得、より良好に脱色部を形成することができる。 Preferably, the laser beam includes polarized light substantially coaxial with the absorption axis of the resin film (polarizer). According to such a laser beam, the difference in absorbance between the polarizer and its peripheral optical member can be further increased, and the decolorization part can be formed more satisfactorily.
　上記照射に際し、例えば、ガルバノミラーを駆動させてレーザーを走査・位置決めしてもよい。また、脱色部の面均一性を得ること等を目的として、ガウシアン分布を主として持つレーザー光強度を均一化するホモジナイザー（ＤＯＥ：Ｄｉｆｆｒａｃｔｉｖｅ　Ｏｐｔｉｃａｌ　Ｅｌｅｍｅｎｔ）を用いてもよい。このような構成を採用することにより、より均一性に優れた脱色部を形成することができる。 In the above irradiation, for example, a galvano mirror may be driven to scan and position the laser. A homogenizer (DOE: Diffractive Optical Element) for uniformizing the laser light intensity mainly having a Gaussian distribution may be used for the purpose of obtaining surface uniformity of the decolorized portion. By adopting such a configuration, it is possible to form a decolorization part with better uniformity.
　なお、Ｘ線を照射することによっても、面均一性を達成しながら上記脱色部が良好に形成され得る。これ以外にも、例えば、波長１００ｐｍ～１５００ｎｍの光を発する光源（例えば、Ｘｅランプ）、バーコード印字用の加熱板等の加熱手段等によっても脱色部は形成され得る。 In addition, the said decoloring part can be formed favorably, achieving surface uniformity also by irradiating X-rays. In addition to this, the decoloring part can also be formed by a heating means such as a light source (for example, an Xe lamp) that emits light having a wavelength of 100 pm to 1500 nm, a heating plate for barcode printing, and the like.
Ｃ．画像表示装置
　本発明の画像表示装置は、上記偏光子を備える。画像表示装置としては、例えば、液晶表示装置、有機ＥＬデバイスが挙げられる。具体的には、液晶表示装置は、液晶セルと、この液晶セルの片側もしくは両側に配置された上記偏光子とを含む液晶パネルを備える。有機ＥＬデバイスは、視認側に上記偏光子が配置された有機ＥＬパネルを備える。偏光子は、その脱色部が搭載される画像表示装置のカメラホール部に対応するように配置される。 C. Image Display Device An image display device of the present invention includes the polarizer. Examples of the image display device include a liquid crystal display device and an organic EL device. Specifically, the liquid crystal display device includes a liquid crystal panel including a liquid crystal cell and the polarizer disposed on one side or both sides of the liquid crystal cell. The organic EL device includes an organic EL panel in which the polarizer is disposed on the viewing side. The polarizer is arranged so as to correspond to the camera hole part of the image display device on which the decoloring part is mounted.
Ｄ．画像表示装置の製造方法
　１つの実施形態においては、上記画像表示装置は、上記二色性物質を含む樹脂フィルムが表面側となるように積層された画像表示パネル（例えば、液晶パネル、有機ＥＬパネル）に、レーザー光を照射して（表面側から）上記脱色部を形成することにより製造される。このような方法によれば、脱色部の位置決めを容易にすることができる。 D. Method for Manufacturing Image Display Device In one embodiment, the image display device includes an image display panel (for example, a liquid crystal panel or an organic EL panel) laminated such that the resin film containing the dichroic material is on the surface side. ) Is irradiated with a laser beam (from the front surface side) to form the decoloring part. According to such a method, positioning of the decoloring part can be facilitated.
　以下、実施例によって本発明を具体的に説明するが、本発明はこれら実施例によって限定されるものではない。なお、透過率の測定方法は以下の通りである。
［透過率（Ｔｓ）］
　顕微分光システム（株式会社ラムダビジョン、ＬＶｍｉｃｒｏ）を用いて測定した。なお、Ｔｓは、ＪＩＳ　Ｚ８７０１の２度視野（Ｃ光源）により測定して視感度補正を行なったＹ値である。
［複屈折ＲＰＶＡ］
　王子計測社製の近赤外位相差測定装置（ＫＯＢＲＡ－３１ｘ１００／ＩＲ）を用いてフィルムの面内位相差を測定し、当該面内位相差値をフィルムの厚みで除することにより算出した。 EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. In addition, the measuring method of the transmittance | permeability is as follows.
[Transmissivity (Ts)]
Measurement was performed using a microspectroscopic system (Lambda Vision Co., Ltd., LVmicro). Note that Ts is a Y value measured by a two-degree field of view (C light source) of JIS Z8701 and corrected for visibility.
[Birefringence R PVA ]
The in-plane retardation of the film was measured using a near-infrared phase difference measuring apparatus (KOBRA-31x100 / IR) manufactured by Oji Scientific Co., Ltd., and the in-plane retardation value was divided by the thickness of the film.
［実施例１］
　固体レーザー（波長：５３２ｎｍ）を用いて、パルス幅１５ピコ秒、パルスエネルギー２０μＪ、スキャン速度１００ｍｍ／ｓｅｃ、繰返し周波数６２４０Ｈｚ、スキャンピッチ２０μｍ、投入エネルギー６２４００μＪ／ｍｍ２、スポット径５５μｍの照射条件にて、総厚１６６μｍの糊付き偏光フィルム（粘着剤層（厚み２０μｍ）／第２の保護フィルム（厚み７７μｍ）／偏光子（厚み２２μｍ）／第１の保護フィルム（厚み４７μｍ））に、視認側（第１の保護フィルム側）から、レーザー光を照射した。こうして、偏光フィルム（偏光子）に、脱色部を形成した。なお、第１の保護フィルムはＴＡＣフィルムに反射防止処理が施されたものであり、第２の保護フィルムは偏光子側から順に負の二軸性フィルム（厚み３５μｍ）／粘着剤層（厚み１２μｍ）／正の二軸性フィルム（厚み３０μｍ）を含む積層構造を有する。 [Example 1]
Using a solid laser (wavelength: 532 nm) under irradiation conditions of a pulse width of 15 picoseconds, a pulse energy of 20 μJ, a scanning speed of 100 mm / sec, a repetition frequency of 6240 Hz, a scanning pitch of 20 μm, an input energy of 62400 μJ / mm 2 and a spot diameter of 55 μm. , A polarizing film with adhesive having a total thickness of 166 μm (adhesive layer (thickness 20 μm) / second protective film (thickness 77 μm) / polarizer (thickness 22 μm) / first protective film (thickness 47 μm)) Laser light was irradiated from the first protective film side. In this way, the decoloring part was formed in the polarizing film (polarizer). The first protective film is a TAC film subjected to antireflection treatment, and the second protective film is a negative biaxial film (thickness 35 μm) / adhesive layer (thickness 12 μm) in order from the polarizer side. ) / Has a laminated structure including a positive biaxial film (thickness 30 μm).
　レーザー光を照射したエリアのみを脱色することができた。未照射部分の複屈折ＲＰＶＡは０．０４０であり、照射部分の複屈折ＲＰＶＡは０．０３１であった。また、未照射部分の透過率は４４．０％であり、照射部分の透過率は６６．２％であった。
　また、照射エリアの表面形状をＷＹＫＯ（ブルカー・エイエックスエス株式会社製）で確認したところ、目立った段差や凹凸はなく面均一性に優れていた。さらに、偏光フィルムの内部を目視で観察したところ、クラックのような破断は確認されなかった。 Only the area irradiated with laser light could be decolorized. Birefringence R PVA unirradiated portion is 0.040, the birefringence R PVA of the irradiated part was 0.031. The transmittance of the unirradiated portion was 44.0%, and the transmittance of the irradiated portion was 66.2%.
Moreover, when the surface shape of the irradiation area was confirmed by WYKO (manufactured by Bruker AXS Co., Ltd.), there were no noticeable steps or irregularities and the surface uniformity was excellent. Furthermore, when the inside of the polarizing film was visually observed, no break such as a crack was confirmed.
［実施例２］
　総厚１２９μｍの糊付き偏光フィルム（粘着剤層（厚み２０μｍ）／第２の保護フィルム（厚み５７μｍ）／偏光子（厚み５μｍ）／第１の保護フィルム（厚み４７μｍ））に、視認側（第１の保護フィルム側）から、実施例１と同様の条件でレーザー光を照射した。こうして、偏光フィルム（偏光子）に、脱色部を形成した。なお、第１の保護フィルムはアクリル系フィルムに反射防止処理が施されたものであり、第２の保護フィルムは偏光子側から順に負の二軸性フィルム（厚み２５μｍ）／粘着剤層（厚み１２μｍ）／正の二軸性フィルム（厚み２０μｍ）を含む積層構造を有する。 [Example 2]
On the viewing side (the first protective film (thickness 47 μm)) on the polarizing side (adhesive layer (thickness 20 μm) / second protective film (thickness 57 μm) / polarizer (thickness 5 μm) / first protective film (thickness 47 μm)) with a total thickness of 129 μm No. 1 protective film side) was irradiated with laser light under the same conditions as in Example 1. In this way, the decoloring part was formed in the polarizing film (polarizer). The first protective film is an acrylic film subjected to antireflection treatment, and the second protective film is a negative biaxial film (thickness 25 μm) / adhesive layer (thickness) in order from the polarizer side. 12 [mu] m) / positive biaxial film (thickness 20 [mu] m).
　レーザー光を照射したエリアのみを脱色することができた。未照射部分の複屈折ＲＰＶＡは０．０４５であり、照射部分の複屈折ＲＰＶＡは０．０１３であった。また、未照射部分の透過率は４３．７％であり、照射部分の透過率は８３．１％であった。
　また、照射エリアの表面形状をＷＹＫＯ（ブルカー・エイエックスエス株式会社製）で確認したところ、目立った段差や凹凸はなく面均一性に優れていた。さらに、偏光フィルムの内部を目視で観察したところ、クラックのような破断は確認されなかった。 Only the area irradiated with laser light could be decolorized. Birefringence R PVA unirradiated portion is 0.045, the birefringence R PVA of the irradiated part was 0.013. In addition, the transmittance of the unirradiated portion was 43.7%, and the transmittance of the irradiated portion was 83.1%.
Moreover, when the surface shape of the irradiation area was confirmed by WYKO (manufactured by Bruker AXS Co., Ltd.), there were no noticeable steps or irregularities and the surface uniformity was excellent. Furthermore, when the inside of the polarizing film was visually observed, no break such as a crack was confirmed.
［実施例３］
　実施例１と同様の偏光フィルムに実施例１と同様の条件でレーザー光を照射した後、固体レーザー（波長：４４７ｎｍ）を用いて、パルス幅１１ナノ秒、パルスエネルギー３０μＪ、スキャン速度１００ｍｍ／ｓｅｃ、繰返し周波数６０００Ｈｚ、スキャンピッチ２０μｍ、投入エネルギー９００００μＪ／ｍｍ２、スポット径２０μｍの照射条件にて、レーザー光を追加照射した。こうして、偏光フィルム（偏光子）に、脱色部を形成した。 [Example 3]
After irradiating the same polarizing film as in Example 1 with laser light under the same conditions as in Example 1, using a solid laser (wavelength: 447 nm), the pulse width is 11 nanoseconds, the pulse energy is 30 μJ, and the scanning speed is 100 mm / sec. Further, laser light was additionally irradiated under irradiation conditions of a repetition frequency of 6000 Hz, a scan pitch of 20 μm, an input energy of 90000 μJ / mm 2 , and a spot diameter of 20 μm. In this way, the decoloring part was formed in the polarizing film (polarizer).
　レーザー光を照射したエリアのみを脱色することができた。未照射部分の複屈折ＲＰＶＡは０．０４５であり、照射部分の複屈折ＲＰＶＡは０．０１１であった。また、未照射部分の透過率は４３．７％であり、照射部分の透過率は８９．１％であった。
　また、照射エリアの表面形状をＷＹＫＯ（ブルカー・エイエックスエス株式会社製）で確認したところ、目立った段差や凹凸はなく面均一性に優れていた。さらに、偏光フィルムの内部を目視で観察したところ、クラックのような破断は確認されなかった。 Only the area irradiated with laser light could be decolorized. Birefringence R PVA unirradiated portion is 0.045, the birefringence R PVA of the irradiated part was 0.011. The transmittance of the unirradiated portion was 43.7%, and the transmittance of the irradiated portion was 89.1%.
Moreover, when the surface shape of the irradiation area was confirmed by WYKO (manufactured by Bruker AXS Co., Ltd.), there were no noticeable steps or irregularities and the surface uniformity was excellent. Furthermore, when the inside of the polarizing film was visually observed, no break such as a crack was confirmed.
（比較例１）
　彫刻刃によるプレス加工にて、実施例１に用いた糊付き偏光フィルムの一部を抜き落とした。
　抜き落とした周辺部分には、１ｍｍ以上の長さのクラックが発生していた。 (Comparative Example 1)
A part of the polarizing film with glue used in Example 1 was removed by press working with an engraving blade.
A crack having a length of 1 mm or more was generated in the peripheral portion that was removed.
（比較例２）
　加温した彫刻刃によるプレス加工にて、実施例１に用いた糊付き偏光フィルムの一部を抜き落とした。
　抜き落とした周辺部分にクラックは確認されなかったが、熱変形による段差が生じており、面均一性が得られなかった。 (Comparative Example 2)
A part of the glue-attached polarizing film used in Example 1 was removed by press working with a heated engraving blade.
Although cracks were not confirmed in the peripheral portion that was removed, a step due to thermal deformation occurred, and surface uniformity could not be obtained.
（比較例３）
　ＣＯ２ガスレーザー（波長：１０．６μｍ）を用いて、パルスエネルギー０．８ｍＪ、スキャン速度３００ｍｍ／ｓｅｃ、繰返し周波数３０００Ｈｚの照射条件でレーザー光を照射したこと以外は実施例１と同様にして、脱色部の形成を試みた。 (Comparative Example 3)
A CO 2 gas laser (wavelength: 10.6 μm) was used in the same manner as in Example 1 except that laser light was irradiated under irradiation conditions of a pulse energy of 0.8 mJ, a scanning speed of 300 mm / sec, and a repetition frequency of 3000 Hz. An attempt was made to form a decolorization part.
　レーザー光を照射したエリアは脱色しておらず、未照射部分および照射部分において、複屈折ＲＰＶＡおよび透過率（４４．０％）のいずれも同じであった。
　また、照射エリアの表面形状を確認したところ、指触で分かるほどの顕著な凹凸（厚み変化）が発生しており、面均一性が得られなかった。なお、内部観察したところ、クラックのような破断は確認されなかった。 The area irradiated with the laser beam was not decolorized, and both the birefringence RPVA and the transmittance (44.0%) were the same in the unirradiated part and the irradiated part.
Moreover, when the surface shape of the irradiation area was confirmed, the remarkable unevenness | corrugation (thickness change) enough to understand by finger touch has generate | occur | produced, and the surface uniformity was not acquired. In addition, as a result of internal observation, no break such as a crack was confirmed.
　本発明の偏光子は、スマートフォン等の携帯電話、ノート型ＰＣ、タブレットＰＣ等のカメラ付き画像表示装置（液晶表示装置、有機ＥＬデバイス）に好適に用いられる。 The polarizer of the present invention is suitably used for a mobile phone such as a smartphone, an image display device with a camera (liquid crystal display device, organic EL device) such as a notebook PC or tablet PC.
　１　　　　　偏光子
　２　　　　　脱色部
  1 Polarizer 2 Decolorizing part

Claims (10)

  1. 　二色性物質を含む樹脂フィルムから構成され、部分的に脱色された脱色部を有し、
    　該脱色部の複屈折ＲＰＶＡが０．０３５以下である、偏光子。     It is composed of a resin film containing a dichroic substance, has a decolorized part that is partially decolored,
    Birefringence R PVA of dehydration the color portion is 0.035 or less, a polarizer.
  2. 　前記脱色部が、１００ｐｍ～１０００ｎｍの波長の光を含むレーザー光を照射して形成される、請求項１に記載の偏光子。 2. The polarizer according to claim 1, wherein the decoloring part is formed by irradiating a laser beam containing light having a wavelength of 100 pm to 1000 nm.
  3. 　前記脱色部が、搭載される画像表示装置のカメラホール部に対応する、請求項１に記載の偏光子。 The polarizer according to claim 1, wherein the decoloring unit corresponds to a camera hole unit of an image display device to be mounted.
  4. 　前記二色性物質がヨウ素である、請求項１に記載の偏光子。 The polarizer according to claim 1, wherein the dichroic substance is iodine.
  5. 　厚みが３０μｍ以下である、請求項１に記載の偏光子。 The polarizer according to claim 1, wherein the thickness is 30 μm or less.
  6. 　二色性物質を含む樹脂フィルムにレーザー光を照射して脱色部を形成する工程を有する、
    　偏光子の製造方法。     Having a step of irradiating a resin film containing a dichroic substance with a laser beam to form a decoloring part,
    A method for producing a polarizer.
  7. 　前記レーザー光が、１００ｐｍ～１０００ｎｍの波長の光を含む、請求項６に記載の製造方法。 The manufacturing method according to claim 6, wherein the laser beam includes light having a wavelength of 100 pm to 1000 nm.
  8. 　前記レーザーが固体レーザーである、請求項６に記載の製造方法。 The manufacturing method according to claim 6, wherein the laser is a solid-state laser.
  9. 　請求項１に記載の偏光子を備える、画像表示装置。 An image display device comprising the polarizer according to claim 1.
  10. 　二色性物質を含む樹脂フィルムが表面側となるように積層された画像表示パネルにレーザー光を照射して、前記脱色部を形成する工程を有する、
    　請求項９に記載の画像表示装置の製造方法。
          Irradiating the image display panel laminated so that the resin film containing the dichroic substance is on the surface side, and forming the decoloring part,
    The manufacturing method of the image display apparatus of Claim 9.
PCT/JP2014/058844 2014-03-27 2014-03-27 Polarizer and image display device WO2015145657A1 (en)

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Citations (8)

* Cited by examiner, † Cited by third party
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JPH06245209A (en) * 1993-02-19 1994-09-02 Sony Corp Camera integrated display device
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JP2005031577A (en) * 2003-07-11 2005-02-03 Fuji Photo Film Co Ltd Polarizing film, polarizing plate and liquid crystal display
JP2009015272A (en) * 2007-07-06 2009-01-22 Wise Media Technology Inc Display device with built-in camera
US20110109829A1 (en) * 2009-11-10 2011-05-12 Mathew Dinesh C Methods for fabricating display structures
JP2012098726A (en) * 2010-10-29 2012-05-24 Apple Inc Camera lens structures and display structures for electronic devices
JP2012137738A (en) * 2010-10-29 2012-07-19 Apple Inc Displays with polarizer windows and opaque masking layers for electronic devices
JP2013205840A (en) * 2012-03-28 2013-10-07 Lg Display Co Ltd Display device

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06245209A (en) * 1993-02-19 1994-09-02 Sony Corp Camera integrated display device
US20040212555A1 (en) * 2003-04-23 2004-10-28 Falco Mark A. Portable electronic device with integrated display and camera and method therefore
JP2005031577A (en) * 2003-07-11 2005-02-03 Fuji Photo Film Co Ltd Polarizing film, polarizing plate and liquid crystal display
JP2009015272A (en) * 2007-07-06 2009-01-22 Wise Media Technology Inc Display device with built-in camera
US20110109829A1 (en) * 2009-11-10 2011-05-12 Mathew Dinesh C Methods for fabricating display structures
JP2012098726A (en) * 2010-10-29 2012-05-24 Apple Inc Camera lens structures and display structures for electronic devices
JP2012137738A (en) * 2010-10-29 2012-07-19 Apple Inc Displays with polarizer windows and opaque masking layers for electronic devices
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