Blinding confirmation system, blinding confirmation method, and blinding method

Abstract

To provide a blinding confirmation system that makes it possible to confirm whether a display is blinded in a space where a polarizing film for preventing peeping is arranged.SOLUTION: There is provided a blinding confirmation system that makes it possible to confirm whether a display arranged in a space which is visible through a polarizer is blinded, and the blinding confirmation system comprises a polarizing film including the polarizer, and a mirror member, wherein the mirror member is arranged on the opposite side of the polarizing film from the side where the display is arranged so as to project an image of the display beyond the polarizing film.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a blind verification system, and a blind verification method and a blind method using the blind verification system. [Background technology]

[0002] In recent years, designs that create a sense of spatial openness in work spaces such as conference rooms and individual booths have become widespread. For example, many work spaces that create a sense of openness by using transparent materials such as glass or acrylic panels for some or all of the partitions that separate the space have been designed and constructed. In many cases, users bring notebook personal computers (PCs) or tablet devices into such work spaces. While such work spaces create a sense of openness, there are cases in which third parties may be able to peek at the information displayed on the display of a notebook PC or other device brought into the work space, which can be a problem.

[0003] On the other hand, the light emitted from the display of a notebook PC or the like is often linearly polarized. Therefore, as a method for solving the problem of peeping, for example, Patent Document 1 proposes arranging a partition equipped with a polarizing film arranged so that the polarization direction of the emitted light and the absorption axis direction are parallel, thereby making the information displayed on the display invisible from the outside (hereinafter, making the information displayed on the display invisible may be referred to as "blinding (the display)" or simply as "blinding"). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 6,552,850 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the polarization direction of the light emitted from the display of a notebook PC or other device brought into the work space is unknown, even if a partition with polarizing film is installed, users may feel unsure as to whether the display is blinded or not, and they will need to go outside the work space to check whether the display is blinded or not.

[0006] The present invention has been made to solve the above-mentioned problems in the conventional art, and its main objective is to provide a blind confirmation system that can confirm whether a display is blinded or not in a space where a polarizing film is placed to prevent peeping. [Means for solving the problem]

[0007] [1] According to one aspect of the present invention, there is provided a blind confirmation system capable of confirming whether a display placed in a space visible through a polarizer is blinded or not, the blind confirmation system comprising: a polarizing film including the polarizer; and a mirror member, the mirror member being disposed on the side of the polarizing film opposite to the side on which the display is disposed so as to reflect an image of the display through the polarizing film. [2] In the blind confirmation system described in [1] above, the polarizing film may have a surface reflectance of 3% or less on a surface on which the display is disposed. [3] In the blind confirmation system according to [1] or [2] above, the polarizing film may further include an anti-reflection layer provided on the side surface on which the display is disposed. [4] In the blind confirmation system according to any one of [1] to [3] above, the mirror member may be a wide-angle mirror member. [5] In the blind confirmation system described in any one of [1] to [4] above, the polarizing film and the mirror member may be integrated together. [6] In the blind confirmation system described in any one of [1] to [4] above, the polarizing film and the mirror member may be arranged with a space therebetween. [7] In the blind confirmation system according to any one of [1] to [4] above, the mirror member may be disposed obliquely with respect to the polarizing film. [8] In the blind confirmation system according to any one of [1] to [7] above, the polarizing film may be arranged to be rotatable. [9] In the blind confirmation system described in any one of [1] to [9] above, the mirror member may include a reflective layer and a protective substrate arranged on the polarizing film side of the reflective layer, and the Re(550) of the protective substrate may be 50 nm or less.

[10] According to another aspect of the present invention, there is provided a method for checking whether a display placed in a space visible through a polarizer is blinded, the method including, in a blind checking system described in any of [1] to [9] above, placing the display in the space so that the mirror member reflects an image of the display through the polarizing film, and observing the image of the display through the polarizing film reflected on the mirror member.

[11] According to another aspect of the present invention, there is provided a method for blinding a display arranged in a space viewable through a polarizer, the method including, in the blind confirmation system described in [8] above, placing the display in the space so that the mirror member reflects an image of the display through the polarizing film, and observing the image of the display through the polarizing film reflected on the mirror member, and if it is confirmed based on the observation that the display is not blinded, rotating the polarizing film to blind the display. Effect of the Invention

[0008] According to an embodiment of the blind confirmation system of the present invention, by placing a mirror member on the outside of a polarizing film, the image of the display reflected on the mirror member can be observed from inside the space, thereby making it possible to confirm whether or not the display is blinded. [Brief description of the drawings]

[0009] [Figure 1] 1(a) and (b) are schematic diagrams illustrating a blind verification system according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram illustrating an example of a method of using a blind verification system according to one embodiment of the present invention. [Diagram 3] FIG. 1 is a schematic diagram illustrating reflection. [Figure 4] FIG. 1 is a schematic diagram illustrating a blind verification system according to one embodiment of the present invention. [Diagram 5] FIG. 1 is a schematic diagram illustrating a blind verification system according to one embodiment of the present invention. [Figure 6] 6(a) and (b) are schematic cross-sectional views illustrating the configuration of one example of a polarizing film that can be used in the present invention. [Figure 7] 7(a) and (b) are schematic diagrams illustrating a blind verification system according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Representative embodiments of the present invention will be described below, but the present invention is not limited to these embodiments. Each embodiment can be appropriately combined unless it is obviously inappropriate. For ease of viewing, the drawings are shown diagrammatically, and the thickness and size of each component in the drawings and the mutual ratio of thicknesses between components are different from the actual ratio. In addition, in this specification, "parallel" includes the case of 0°±10°, and may be preferably 0°±5°, and more preferably 0°±3°. "Orthogonal" includes the case of 90°±10°, and may be preferably 90°±5°, and more preferably 90°±3°.

[0011] A. Blind Confirmation System A blind confirmation system according to an embodiment of the present invention is a blind confirmation system capable of confirming whether a display placed in a space visible through a polarizer is blinded or not, and comprises a polarizing film including the polarizer and a mirror member, the mirror member being positioned on the side of the polarizing film opposite the side on which the display is positioned so as to reflect an image of the display through the polarizing film.

[0012] 1(a) and (b) are schematic diagrams illustrating a blind confirmation system 100 according to one embodiment of the present invention, showing a space 1 visible through a polarizer as viewed from above. The space 1 is defined by walls 1a, 1b, 1c, and 1d. The wall 1c is made of a transparent member, and a polarizing film 10 including a polarizer 12 is disposed inside the wall 1c, and a mirror member 20 is disposed outside the wall 1c. The polarizing film 10 and the mirror member 20 are each attached to the wall 1c via, for example, an adhesive layer (adhesive layer, adhesive layer, etc.). The image display device 30 includes a display 32, and is disposed in the space 1 with the display 32 facing the polarizing film 10. The position where the image display device 30 is disposed is within the field of view of the mirror member 20 (within the range reflected by the mirror member 20). This allows the mirror member 20 to reflect the image of the display 32 through the polarizing film 10. In FIG. 1, arrow X1 indicates the polarization direction of light emitted from display 32, arrow X2 indicates the absorption axis direction of polarizer 12 included in polarizing film 10, and the top-to-bottom direction on the page is regarded as the vertical direction and the left-to-right direction is regarded as the horizontal direction.

[0013] According to the above system 100, when the polarization direction X1 of the light (light representing an image) emitted from the display 32 is parallel to the absorption axis direction X2 of the polarizer 12 included in the polarizing film 10 (FIG. 1(a)), the light emitted from the display 32 is absorbed by the polarizing film 10. Therefore, when a third party A located outside the space 1 observes the display 32 through the polarizing film 10, the third party A sees the display 32 as a black screen, and the display 32 is blinded. On the other hand, in the space 1, the light emitted from the display 32 is absorbed by the polarizing film 10 and is not reflected by the mirror member 20. Therefore, the light can be seen as a black screen by a user B located in the space 1. This allows the user B to confirm that the display 32 is blinded in the space 1.

[0014] On the other hand, when the polarization direction X1 of the light (light representing an image) emitted from the display 32 and the absorption axis direction X2 of the polarizer 12 included in the polarizing film 10 are perpendicular to each other (FIG. 1(b)), the light emitted from the display 32 passes through the polarizing film 10. Therefore, a third party A located outside the space 1 can view the display image of the display 32 through the polarizing film 10. On the other hand, in the space 1, the light emitted from the display 32 passes through the polarizing film 10 and is reflected by the mirror member 20, so that the light can be viewed as a display image by a user B located in the space 1. The image (reflected image) of the display 32 through the polarizing film 10 reflected on the mirror member 20 is a left-right inverted image, and a left-right inverted display image can be viewed. This allows the user B to confirm that the display 32 is not blinded in the space 1.

[0015] In one embodiment, the polarizing film 10 is arranged to be rotatable. According to this configuration, as shown in FIG. 2, a user who has confirmed that the display 32 is not blinded can rotate the polarizing film 10 so that the polarization direction X1 of the light emitted from the display 32 and the absorption axis direction X2 of the polarizer 12 included in the polarizing film 10 are parallel to each other, thereby blinding the display 32. For example, by rotating the polarizing film 10 clockwise or counterclockwise by about 90°, the display 32 can be changed from an unblinded state (e.g., a state in which the direction X1 and the direction X2 are perpendicular to each other) to a blinded state (e.g., a state in which the direction X1 and the direction X2 are parallel to each other). The rotation mechanism is not limited, and the user may manually change the installation angle, or the display may be configured to rotate automatically to the input installation angle.

[0016] In the illustrated example, the polarizing film 10 and the mirror member 20 are laminated via a wall 1c, but the configuration is not limited to the illustrated example. For example, the polarizing film 10 and the mirror member 20 may be laminated in this order on the outside of the space 1 of the wall 1c. In addition, the polarizing film 10 and the mirror member 20 do not need to be integrated. For example, the mirror member 20 may be disposed obliquely with respect to the polarizing film 10. In addition, for example, the polarizing film 10 and the mirror member 20 may be disposed with a space between them.

[0017] As shown in FIG. 3, in a configuration in which the polarizing film 10 and the mirror member 20 are integrated by lamination, when the display 32 is in a blinded state, the image of the display 32 (black screen) seen through the polarizing film 10 by reflection from the mirror member 20 is superimposed on the image of the display 32 (a left-right inverted display image) by reflection from the polarizing film 10 and is reflected in the screen, which may make it difficult to clearly determine whether the display 32 is blinded.

[0018] 4, in a configuration in which the mirror member 20 is disposed obliquely with respect to the polarizing film 10, the reflection angle at the polarizing film 10 and the reflection angle at the mirror member 20 can be made different. As a result, the image formed by reflection at the mirror member 20 (black screen) and the image formed by reflection at the polarizing film 10 (left-right inverted display image) can be distinguished by shifting them, and the above-mentioned problem of reflection can be suppressed. This makes it easy to determine whether the display 32 is blinded or not.

[0019] In the above configuration, the angle θ1 between the main surface of the polarizing film 10 and the main surface of the mirror member 20 is not limited as long as the effects of the present invention can be obtained, and may be, for example, 1° to 40°, or, for example, 10° to 30°.

[0020] Also, for example, as shown in FIG. 5, according to a configuration in which the polarizing film 10 and the mirror member 20 are arranged with a space between them, the reflected light from the polarizing film 10 and the reflected light from the mirror member 20 can be shifted. As a result, the image formed by reflection from the mirror member 20 (black screen) and the image formed by reflection from the polarizing film 10 (left-right inverted display image) can be distinguished by shifting them, and the above-mentioned problem of reflection can be suppressed. This makes it easy to determine whether the display 32 is blinded or not. As an example of the configuration shown in FIG. 5, a configuration in which the polarizing film is installed on a wall surface that defines a space, and a mirror member is installed on another wall that is separated from the wall by a passageway can be given.

[0021] Also, for example, reflection on the polarizing film surface can be suppressed by using a polarizing film with low surface reflectance. This suppresses the above-mentioned problem of reflection, making it easy to determine whether the display is blinded or not. The surface reflectance of the polarizing film on the inner surface of the space is, for example, 3% or less, preferably 2.5% or less, more preferably 2% or less, and even more preferably 1% or less, and can be, for example, 0.1% or more.

[0022] <Polarizing film> 6(a) and (b) are schematic cross-sectional views each illustrating the configuration of an example of a polarizing film. The polarizing film 10a includes a polarizer 12, an inner protective layer 14a disposed on one side thereof, and an outer protective layer 14b disposed on the other side thereof. Here, the inner and outer refer to the inner and outer sides of the space 1.

[0023] The polarizing film 10b includes a polarizer 12, an inner protective layer 14a disposed on one side of the polarizer 12, an outer protective layer 14b disposed on the other side, and an antireflection layer 16 disposed on the side of the inner protective layer 14a opposite to the side on which the polarizer 12 is disposed. The antireflection layer 16 may be the inner outermost layer of the polarizing film 10b. By providing an antireflection layer on the inner surface, a polarizing film having a surface reflectance of the inner surface within the above-mentioned preferred range can be suitably obtained.

[0024] The inner protective layer and the outer protective layer are attached to the polarizer via, for example, an adhesive layer (for example, an adhesive layer). Depending on the purpose, either the inner protective layer or the outer protective layer may be omitted.

[0025] The polarizing films 10a and 10b may include a pressure-sensitive adhesive layer 18 as the outermost layer. When the polarizing films 10a and 10b include a pressure-sensitive adhesive layer as the outermost layer, the pressure-sensitive adhesive layer allows the polarizing films to be suitably attached to transparent members that define a space, such as walls and partitions. A release liner may be temporarily attached to the surface of the pressure-sensitive adhesive layer 18 until the polarizing films 10a and 10b are used.

[0026] The thickness of the polarizing film excluding the pressure-sensitive adhesive layer can be, for example, 10 μm to 300 μm, preferably 30 μm to 200 μm, and more preferably 50 μm to 120 μm.

[0027] Any suitable polarizer may be used as the polarizer. The polarizer is typically composed of a polyvinyl alcohol (PVA)-based resin film containing a dichroic material (e.g., iodine). Examples of PVA-based resins include polyvinyl alcohol, partially formalized polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and partially saponified ethylene-vinyl acetate copolymer. For example, the resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

[0028] Specific examples of polarizers made of a single-layer resin film include hydrophilic polymer films such as PVA films, partially formalized PVA films, and partially saponified ethylene-vinyl acetate copolymer films that have been dyed with iodine or a dichroic substance such as a dichroic dye and stretched, and polyene-based oriented films such as dehydrated PVA films and dehydrochlorinated polyvinyl chloride films. A polarizer obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferably used because of its excellent optical properties.

[0029] The dyeing with iodine is carried out, for example, by immersing the PVA-based film in an aqueous iodine solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching may be carried out after the dyeing treatment, or may be carried out while dyeing. Alternatively, the film may be stretched and then dyed. If necessary, the PVA-based film may be subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, or the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, it is possible to wash off dirt and antiblocking agents on the surface of the PVA-based film, and also to swell the PVA-based film and prevent uneven dyeing.

[0030] Specific examples of polarizers obtained using a laminate include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate. A polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate can be produced by, for example, applying a PVA-based resin solution to the resin substrate and drying the resin substrate to form a PVA-based resin layer on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer; stretching and dyeing the laminate to make the PVA-based resin layer into a polarizer. In this embodiment, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is preferably formed on one side of the resin substrate. The stretching typically includes immersing the laminate in an aqueous boric acid solution to stretch it. Furthermore, the stretching may further include, as necessary, stretching the laminate in air at a high temperature (for example, 95° C. or higher) before stretching in the aqueous boric acid solution. In addition, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate is heated while being transported in the longitudinal direction to shrink the laminate by 2% or more in the width direction. Typically, the manufacturing method of this embodiment includes subjecting the laminate to an air-assisted stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment in this order. By introducing the auxiliary stretching, even when PVA is applied onto a thermoplastic resin, it is possible to increase the crystallinity of the PVA, and to achieve high optical properties. In addition, by simultaneously increasing the orientation of the PVA in advance, problems such as a decrease in the orientation of the PVA or dissolution when immersed in water in the subsequent dyeing and stretching steps can be prevented, and high optical properties can be achieved. Furthermore, when the PVA-based resin layer is immersed in a liquid, the orientation of the polyvinyl alcohol molecules can be disturbed and the orientation can be reduced, compared to when the PVA-based resin layer does not contain a halide. This can improve the optical properties of a polarizer obtained by immersing the laminate in a liquid through a treatment process such as a dyeing treatment and an underwater stretching treatment. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction through a drying shrinkage treatment.The obtained resin substrate / polarizer laminate may be used as it is (i.e., the resin substrate may be used as a protective layer for the polarizer), or any suitable protective layer may be laminated on the peeled surface of the resin substrate / polarizer laminate after peeling the resin substrate from the resin substrate / polarizer laminate, or on the surface opposite to the peeled surface, depending on the purpose. Details of the method for producing such a polarizer are described in, for example, JP2012-73580A and JP6470455A. The entire disclosures of these publications are incorporated herein by reference.

[0031] The thickness of the polarizer is typically 20 μm or less, for example, 12 μm or less, preferably 10 μm or less, more preferably 1 μm to 8 μm, and further preferably 3 μm to 7 μm.

[0032] The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizer is preferably 41.0% to 46.0%, more preferably 42.0% to 45.0%. The degree of polarization of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and even more preferably 99.9% or more.

[0033] The protective layer is composed of any suitable resin film. Representative materials for the resin film include cellulose resins such as triacetyl cellulose (TAC), cycloolefin resins such as polynorbornene, (meth)acrylic resins, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene, and polycarbonate resins. Representative examples of (meth)acrylic resins include (meth)acrylic resins having a lactone ring structure. (Meth)acrylic resins having a lactone ring structure are described in, for example, JP-A-2000-230016, JP-A-2001-151814, JP-A-2002-120326, JP-A-2002-254544, and JP-A-2005-146084. These publications are incorporated herein by reference.

[0034] The thickness of the protective layer is preferably from 10 μm to 80 μm, more preferably from 12 μm to 40 μm, and further preferably from 15 μm to 35 μm.

[0035] The antireflection layer is a low-reflection layer provided for the purpose of preventing reflection of external light on the surface of the polarizing film. Any appropriate configuration can be adopted as the antireflection layer. For example, there are antireflection layers such as a multi-coat type in which a plurality of thin films with different refractive indices are laminated to cause light to interfere with each other and reduce regular reflection, and a moth-eye type having an uneven structure in which a large number of minute protrusions are regularly arranged at intervals equal to or less than the shortest wavelength of the wavelength range of light to be prevented from being reflected. The moth-eye type antireflection layer can prevent light reflection by continuously changing the refractive index for incident light in the thickness direction and eliminating discontinuous interfaces of the refractive index.

[0036] The antireflection layer can be formed on a supporting substrate. In this case, an antireflection film having a laminated structure of a supporting substrate and an antireflection layer can be attached to an inner protective layer (or a polarizer when the inner protective layer is omitted) via an adhesive layer (typically, an adhesive layer or a pressure-sensitive adhesive layer). As the antireflection film, various commercial products are available. Alternatively, the antireflection layer may be provided directly on the inner protective layer. The multi-coat type antireflection layer can generally be prepared by a vapor deposition method.

[0037] The surface reflectance of the antireflection layer is, for example, 3% or less, preferably 2.5% or less, more preferably 2% or less, and further preferably 1% or less, and may be, for example, 0.1% or more.

[0038] <Mirror parts> At least one side of the mirror member is a reflective surface, and the reflective surface reflects the light transmitted through the polarizing film, allowing a user to view an image (reflected image) on the display through the polarizing film from within the space.

[0039] The total light reflectance of the reflecting surface of the mirror member is, for example, 80.0% or more, preferably 85.0% or more, more preferably 90.0% or more. The total light reflectance may be, for example, 99.0% or less, or, for example, 98.0% or less. From the viewpoint of obtaining a clear reflected image, it is preferable that the reflection of the reflecting surface is a specular reflection. Therefore, the total light reflectance of the reflecting surface may be a regular reflectance.

[0040] Representative examples of the mirror member include a glass mirror, a resin mirror, etc., each of which includes a reflective layer and a protective substrate. When the surface of the protective substrate is used as a reflective surface, a protective coating layer may be provided on the side of the reflective layer opposite to the side where the protective substrate is disposed, for the purpose of preventing moisture, rust, etc.

[0041] The reflective layer is typically a metal layer, preferably a mirror-finished metal layer. Examples of the material for the metal layer include metals such as aluminum, silver, chromium, and tin, and alloys or oxides of these metals, and aluminum and alloys containing aluminum are preferred.

[0042] The metal layer may be a layer formed by a dry process, a layer formed by spraying metal, or a metal foil. Specific examples of dry processes include PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition). Examples of PVD include vacuum deposition, reactive deposition, ion beam assisted deposition, sputtering, and ion plating. Examples of CVD include plasma CVD.

[0043] The thickness of the metal layer formed by the dry process is preferably 10 nm to 150 nm, more preferably 20 nm to 100 nm. The thickness of the metal layer made of metal foil is preferably 1 μm to 200 μm, more preferably 10 μm to 100 μm.

[0044] Examples of materials constituting the protective substrate include transparent resins such as polycarbonate resin, acrylic resin, polystyrene resin, polyethylene resin, and polyethylene terephthalate resin, and glass.

[0045] When the protective substrate has an in-plane retardation (e.g., Re(550) of more than 50 nm, e.g., 100 nm or more), in a configuration in which a polarizing film and a mirror member are integrated, if the angle between the absorption axis direction of the polarizing film and the slow axis direction of the protective substrate of the mirror member is 10° to 80° clockwise or counterclockwise based on the absorption axis direction of the polarizing film, the reflected light may be colored due to the in-plane retardation of the protective substrate. In response to this, by integrating the polarizing film and the mirror member (for example, by bonding them together via an adhesive layer) so that the absorption axis direction of the polarizing film and the slow axis direction of the protective substrate are parallel or perpendicular to each other, it is possible to prevent the reflected light from being colored due to the in-plane retardation of the protective substrate. Furthermore, in a configuration in which the polarizing film and the mirror member are placed with a space between them and only the polarizing film is capable of rotating, the angle between the absorption axis direction of the polarizing film and the slow axis direction of the protective substrate of the mirror member changes continuously as the polarizing film rotates, so that uncolored and colored states appear alternately, making it difficult to clearly determine whether the display is blinded or not. In contrast, by using a protective substrate having Re(550) of, for example, 50 nm or less, for example, 0 nm to 30 nm, it is possible to prevent coloring of reflected light due to the in-plane retardation of the protective substrate when the polarizing film is rotated. In addition, when the in-plane retardation of the protective substrate is within the above range, it is possible to prevent the above-mentioned coloring problem when the angle between the absorption axis direction of the polarizing film and the slow axis direction of the protective substrate of the mirror member is 10° to 80° clockwise or counterclockwise based on the absorption axis direction of the polarizing film. The above Re(550) is the in-plane retardation measured with light having a wavelength of 550 nm at 23° C., and is calculated by the formula: Re(550)=(nx-ny)×d, where d (nm) is the thickness of the substrate. “nx” is the refractive index in the direction in which the in-plane refractive index is maximum (i.e., the slow axis direction), and “ny” is the refractive index in the in-plane direction perpendicular to the slow axis (i.e., the fast axis direction).

[0046] The mirror member may be a stainless steel mirror without a protective substrate. Since the stainless steel mirror has a mirror surface (reflective surface) formed by polishing the surface of the stainless steel, it is possible to prevent the reflected light from being colored due to the in-plane retardation of the protective substrate when the polarizing film is rotated.

[0047] In one embodiment, the mirror member is a wide-angle mirror member. The wide-angle mirror member can reflect a wider range than a normal mirror member (flat mirror) whose reflective layer is flat. Therefore, as shown in Fig. 7, the range in which a display for checking the presence or absence of blinds can be placed and the range in which an image reflected on the mirror member can be confirmed can be widened (Fig. 7(a) shows an embodiment using a normal mirror member, and Fig. 7(b) shows an embodiment using a wide-angle mirror member).

[0048] Any suitable configuration can be adopted as the wide-angle mirror member. Preferred examples of the wide-angle mirror member include a convex mirror in which the reflective layer has a convex surface, a hemispherical mirror, and a Fresnel mirror. The Fresnel mirror may have a configuration in which, for example, a protective substrate is used on the back surface of which a number of annular grooves with V-shaped cross sections having successively different diameters and inclination angles are arranged concentrically, and a reflective layer is laminated on the annular grooves on the back surface. The shape of the mirror member is arbitrary, and is not limited to a square shape, and may be any shape such as a circle or an ellipse.

[0049] B. How to use the blind confirmation system The blind confirmation system described in Section A can be used to confirm whether a display arranged in a space visible through a polarizer is blinded or not. Therefore, according to another aspect of the present invention, there is provided a method for confirming whether a display arranged in a space visible through a polarizer is blinded or not, the method including, in the blind confirmation system described in Section A, disposing the display in the space so that the mirror member reflects an image of the display through the polarizing film, and observing the image of the display through the polarizing film reflected on the mirror member. In this method, if the image of the display reflected on the mirror member is observed as a black screen, it can be confirmed that the display is blinded, and if a display image is observed from the image of the display, it can be confirmed that the display is not blinded.

[0050] In the above method, according to a blind confirmation system in which a polarizing film is rotatably arranged, if it is confirmed based on the observation that the display is not blinded, the display can be blinded by rotating the polarizing film. EXAMPLES

[0051] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0052] <Thickness> The thickness of 10 μm or less was measured using a scanning electron microscope (manufactured by JEOL, product name "JSM-7100F"), and the thickness of more than 10 μm was measured using a digital micrometer (manufactured by Anritsu, product name "KC-351C"). <Single unit transmittance and polarization degree> A spectrophotometer (Otsuka Electronics Co., Ltd., "LPF-200") was used to measure the single transmittance Ts, parallel transmittance Tp, and crossed transmittance Tc of a laminate having a configuration of [thermoplastic resin substrate / polarizer]. These Ts, Tp, and Tc are Y values ​​measured using a 2-degree visual field (C light source) according to JIS Z8701 and corrected for visibility. The degree of polarization was calculated from the obtained Tp and Tc using the following formula. Degree of polarization (%)={(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100 <Surface reflectance> A measurement sample was obtained by attaching an anti-reflection film to a black acrylic plate so that the anti-reflection layer was exposed. The total light reflectance of the measurement sample was measured using a spectrophotometer (Hitachi High-Tech Corporation, "UH-4150"). The total light reflectance was calculated by using a standard white plate of barium sulfate as a reference sample and calculating the ratio (relative reflectance) of the amount of light reflected by the measurement sample to the amount of light reflected by the reference sample. The total light reflectance was measured at wavelengths from 380 nm to 780 nm at 5 nm intervals, and the measured values ​​were multiplied by a weighting coefficient obtained from the spectrum of the C light source and the wavelength distribution of the luminosity of a 2-degree visual field, and averaged to obtain the total light reflectance (Y value).

[0053] [Production Example 1: Polarizing film A] As a thermoplastic resin substrate, a long amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a Tg of about 75° C. was used, and one side of the resin substrate was subjected to a corona treatment. A PVA aqueous solution (coating solution) was prepared by adding 13 parts by weight of potassium iodide to 100 parts by weight of a PVA-based resin made by mixing polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name "GOHSEFFIMER") in a ratio of 9:1, and dissolving the mixture in water. The above PVA aqueous solution was applied to the corona-treated surface of a resin substrate and dried at 60° C. to form a PVA-based resin layer with a thickness of 13 μm, thereby producing a laminate. The obtained laminate was uniaxially stretched 2.4 times in the machine direction (longitudinal direction) in an oven at 130° C. (auxiliary air stretching treatment). Next, the laminate was immersed in an insolubilizing bath (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40° C. for 30 seconds (insolubilizing treatment). Next, the film was immersed in a dye bath (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by weight of water) at a liquid temperature of 30°C for 60 seconds while adjusting the concentration so that the single transmittance (Ts) of the finally obtained polarizer would be the desired value (dyeing treatment). Next, the piece was immersed in a crosslinking bath (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40° C. for 30 seconds (crosslinking treatment). Thereafter, the laminate was immersed in an aqueous boric acid solution (boric acid concentration: 4% by weight, potassium iodide concentration: 5% by weight) at a liquid temperature of 70°C and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds to a total stretch ratio of 5.5 times (underwater stretching treatment). Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20° C. (cleaning treatment). Thereafter, the film was dried in an oven maintained at about 90° C. while being brought into contact with a SUS heated roll whose surface temperature was maintained at about 75° C. (drying shrinkage treatment). In this way, a polarizer having a thickness of about 5 μm was formed on the thermoplastic resin substrate, and a laminate having a configuration of [thermoplastic resin substrate / polarizer] was obtained. The single transmittance Ts of the polarizer was 43%, and the polarization degree was 99.9%.

[0054] A triacetyl cellulose (TAC) film (thickness 25 μm) was attached to the surface of the obtained polarizer (the surface opposite to the resin substrate) via an adhesive layer. Next, after peeling off the resin substrate, a similar TAC film was attached to the peeled surface via an adhesive layer, and an acrylic adhesive layer was laminated on top of it together with a release liner. In this way, a polarizing film A having a structure of [TAC film (inner protective layer) / polarizer / TAC film (outer protective layer) / adhesive layer] was obtained.

[0055] [Production Example 2: Polarizing Film B] A polarizing film B having a structure of [antireflection layer / TAC film (inner protective layer) / polarizer / TAC film (outer protective layer) / adhesive layer] was obtained in the same manner as in Production Example 1, except that an antireflection film (manufactured by Toppan Tomoegawa Optical Films Co., Ltd.) having a laminated structure of a support substrate and an antireflection layer was attached to the surface of the inner protective layer via an acrylic adhesive layer. The surface reflectance of the antireflection film on the antireflection layer side was 0.9%.

[0056] [Example 1] A commercially available notebook PC (HP's "Elite Dragonfly G2") was placed in a room defined by four walls, with a glass window measuring 2500 mm in height and 3000 mm in width on the wall facing the corridor. The display of this notebook PC emits linearly polarized light. The adhesive layer surface of polarizing film A was attached to the entire inner surface of the window (in other words, the surface on the side where the notebook PC was placed) in such a way that the absorption axis direction of the polarizer of polarizing film A was parallel to the polarization direction of the linearly polarized light emitted from the display. Next, mirror A, measuring 300 mm in height and 200 mm in width, was attached to the outside surface of the window via an adhesive layer so that the reflective surface faced the window. At this time, the attachment was performed so that mirror A reflected the image on the display of the notebook PC through polarizing film A. Mirror A was a glass mirror having a flat aluminum deposition layer as a reflective layer. In this manner, a blind confirmation system was constructed.

[0057] In the above blind confirmation system, the notebook PC was turned on and an image was displayed on the display. When the display was observed from the corridor through the window, a black screen was observed. This confirmed that the image displayed on the display could not be observed from outside the window, and that the display was blinded by polarizing film A. Next, when the image of the display reflected by mirror A was observed from inside the room, the overall color tone of the display was observed to be very dark. This confirmed that the display was blinded by polarizing film A. On the other hand, the displayed image was faintly visible in the image of the display observed inside the room, indicating that light reflected from the surface of polarizing film A (more specifically, the surface of the inner protective layer of polarizing film A) was being reflected. This type of reflection was not desirable when checking the blinding condition.

[0058] [Example 2] A blind confirmation system was constructed in the same manner as in Example 1, except that polarizing film B was used instead of polarizing film A.

[0059] In the above blind confirmation system, the notebook PC was turned on and an image was displayed on the display. When the display was observed from the corridor through the window, a black screen was observed. This confirmed that the image displayed on the display could not be observed from outside the window, and that the display was blinded by polarizing film B. Next, when the image of the display reflected by mirror A was observed from inside the room, there was no reflection and it was observed as a black screen. From this, it was easy to confirm from inside the room that the display was blinded by polarizing film B.

[0060] [Example 3] A blind confirmation system was configured in the same manner as in Example 1, except that a Fresnel mirror B (manufactured by COMI Corporation, "FF Mirror") was used instead of mirror A.

[0061] In the above blind confirmation system, the notebook PC was turned on and an image was displayed on the display. When the display was observed from the corridor through the window, a black screen was observed. This confirmed that the image displayed on the display could not be observed from outside the window, and that the display was blinded by polarizing film A. Next, when the image of the display reflected by Fresnel mirror B was observed from inside the room, the overall color tone of the display was observed to be very dark. This confirmed that the display was blinded by polarizing film A. On the other hand, the displayed image was faintly visible in the image of the display observed inside the room, indicating that the reflected light from the surface of polarizing film A had been reflected. This type of reflection was not desirable in terms of confirming the blinding condition. On the other hand, Fresnel mirror B can reflect a wider range than mirror A, so there was a higher degree of freedom in the placement position of the notebook PC when checking the blind situation than in the first embodiment.

[0062] [Example 4] A blind confirmation system was configured in the same manner as in Example 2, except that a Fresnel mirror B (manufactured by COMI Corporation, "FF Mirror") was used instead of mirror A.

[0063] In the above blind confirmation system, the notebook PC was turned on and an image was displayed on the display. When the display was observed from the corridor through the window, a black screen was observed. This confirmed that the image displayed on the display could not be observed from outside the window, and that the display was blinded by polarizing film B. Next, when the image of the display reflected by Fresnel mirror B was observed from inside the room, there was no reflection and it was observed as a black screen. From this, it was easily confirmed from inside the room that the display was blinded by polarizing film B. In addition, since the Fresnel mirror B can reflect a wider range than the mirror A, the degree of freedom in the placement position of the notebook PC when checking the blind condition was higher than in the second embodiment.

[0064] [Comparative Example 1] A blind confirmation system was configured in the same manner as in Example 1, except that mirror A was not used.

[0065] In the above blind confirmation system, the notebook PC was turned on and an image was displayed on the display. When the display was observed from the corridor through the window, a black screen was observed. This confirmed that the image displayed on the display could not be observed from outside the window, and that the display was blinded by polarizing film A. Next, when polarizing film A was observed from inside the room, the image of the display was visible due to reflection on the surface of polarizing film A, and the image was only a left-right inverted display image. Therefore, it was not possible to confirm from inside the room whether the display was blinded by polarizing film A or not.

[0066] The configurations of the blind confirmation systems of the above-mentioned embodiment and comparative example and the blind confirmation results are summarized in Table 1. [Table 1]

[0067] It can be seen that the blind confirmation system according to the embodiment of the present invention makes it possible to confirm whether or not a display is blinded in a space in which a polarizing film is applied. [Industrial Applicability]

[0068] The blind confirmation system according to the embodiment of the present invention can be suitably used in work spaces where information management is required. [Explanation of symbols]

[0069] 1 space 10 Polarizing film 12 Polarizer 16 Anti-reflection layer 20 Mirror material 32 Display 100 Blind Confirmation System

Claims

1. A blind confirmation system capable of confirming whether or not a display arranged in a space visible through a polarizer is blinded, comprising: A polarizing film including the polarizer and a mirror member, The mirror member is disposed on the opposite side of the polarizing film from the side on which the display is disposed so as to reflect an image of the display through the polarizing film. Blind confirmation system.

2. 2. The blind confirmation system according to claim 1, wherein the surface reflectance of the polarizing film on the side on which the display is disposed is 3% or less.

3. 2. The blind viewing system of claim 1, wherein the polarizing film further comprises an anti-reflection layer provided on the side surface on which the display is disposed.

4. 2. The blind verification system of claim 1, wherein said mirror member is a wide angle mirror member.

5. The blind viewing system of claim 1 , wherein the polarizing film and the mirror member are integrated.

6. The blind confirmation system according to claim 1 , wherein the polarizing film and the mirror member are disposed with a space therebetween.

7. The blind viewing system of claim 1 , wherein the mirror member is disposed at an angle to the polarizing film.

8. The blind verification system according to claim 1 , wherein the polarizing film is rotatably disposed.

9. the mirror member includes a reflective layer and a protective substrate disposed on the polarizing film side of the reflective layer, 2. The blind verification system of claim 1, wherein the protective substrate has an Re(550) of 50 nm or less.

10. 1. A method for determining whether a display disposed in a space viewable through a polarizer is blinded, comprising the steps of:

10. The blind viewing system according to claim 1, further comprising: disposing the display in the space such that the mirror member reflects an image of the display through the polarizing film; and Observing an image of the display through the polarizing film reflected on the mirror member; A method comprising:

11. 1. A method for blinding a display located in a space viewable through a polarizer, comprising:

9. The blind viewing system of claim 8, further comprising: disposing the display within the space such that the mirror member reflects an image of the display through the polarizing film; and Observing an image of the display through the polarizing film reflected on the mirror member; Including, If the display is determined to be unblinded based on said observation, then rotating said polarizing film to blind said display.

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