Anti-peep sheet and method for producing same

Abstract

To provide a peep preventing sheet and its manufacturing method capable of preventing contamination and eliminating the possibility of deterioration in the function of an authentication sensor by preventing foreign matter such as dust from entering the inside.SOLUTION: The peep preventing sheet 10 is laminated on the surface of a smartphone as an operation screen and controls a visible angle within a predetermined range, and includes a flexible louver layer 11 facing the surface of the smartphone in a state where a plurality of light transmission bands 12 and light shielding bands 13 are alternately arranged, and a transparent window frame 15 fitted into a facing hole 14 facing the face authentication sensor of the louver layer 11, wherein the light transmission bands 12 and the transparent window frame 15 are formed of light transmissive silicone rubber, and the light shielding bands 13 of the louver layer 11 are formed of colored silicone rubber. Since the transparent window frame 15 is closely fitted into the opposed hole 14 without a clearance, the intrusion of foreign matter such as dust into the opposed hole 14 of the peep preventing sheet 10 can be prevented.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an anti-spy sheet that is laminated on the operation screen of a mobile information device such as a smartphone to control the viewing angle within a predetermined range, and a method for manufacturing the same. [Background technology]

[0002] Smartphones are multifunctional portable information devices similar to computers, and often store a large amount of information that one does not want third parties to know. To reduce the risk of information leakage, an anti-spy sheet 10A shown in Fig. 12 is sometimes laminated and adhered to the entire surface, which is the operation screen. This type of anti-spy sheet 10A is formed from a hard resin film in which multiple transmissive and absorbent areas are arranged alternately (see Patent Documents 1 and 2), and functions to narrow the visible angle (visible range) in the left and right lateral directions.

[0003] To prevent unauthorized use and the leakage of personal information, some smartphones are equipped with a screen lock function and various authentication sensors, such as a face authentication sensor, that are installed on the upper part of the surface to unlock the screen. In this type of smartphone, if the anti-peeping sheet 10A is located in the area facing the face authentication sensor, the camera of the face authentication sensor may capture an image of the user's face, which could cause the face authentication sensor to malfunction. In light of this, a horizontally elongated through-hole 27 shown in FIG. 12 is perforated in the area facing the face authentication sensor of the conventional anti-peeping sheet 10A. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2021-507285 [Patent Document 2] International Publication No. 2018 / 225714 Summary of the Invention [Problem to be solved by the invention]

[0005] The conventional anti-spy sheet 10A is formed as described above, and has through-holes 27 drilled in the portions facing the face authentication sensor, thereby eliminating the risk of malfunction of the face authentication sensor. However, foreign matter such as dust can get into the through-holes 27 of the anti-spy sheet 10A, which can contaminate the anti-spy sheet 10A and cause the face authentication sensor to malfunction, resulting in a decrease in functionality. One possible way to resolve this concern is to fill the through-holes 27 with a light-transmitting hard filler, but because the anti-spy sheet 10A is hard, it is not technically easy to completely fill the through-holes with a hard filler.

[0006] The present invention has been made in consideration of the above, and aims to provide an anti-peeping sheet and a manufacturing method thereof that can prevent foreign matter such as dust from entering the interior, thereby preventing contamination and eliminating the risk of functional degradation of the authentication sensor. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention is a display device that is laminated on the operation screen of a portable information device and controls the visible angle within a predetermined range, The device includes a louver layer facing the operation screen of the portable information device with a plurality of light-transmitting bands and light-blocking bands arranged alternately, and light-transmitting rubber fitted into opposing holes in the louver layer facing the authentication sensor of the operation screen of the portable information device, and is characterized in that the light-transmitting bands and light-transmitting rubber of the louver layer are each formed from light-transmitting silicone rubber, and the light-blocking bands of the louver layer are formed from colored silicone rubber.

[0008] It is preferable that the display panel further includes a light-transmitting silicone mirror layer laminated on one side of the louver layer and adhesive to the operating screen of the portable information device, and a light-transmitting resin film layer adhered to the other side of the louver layer. The film may also include a light-transmitting adhesive layer laminated on the resin film layer.

[0009] Furthermore, it is preferable that the silicone rubber of the louver layer has a tensile strength of 7.5 MPa or more and 13.5 MPa or less when measured in accordance with JIS K6251, an elongation at break of 270% or more and 490% or less when measured in accordance with JIS K6251, and a tear strength of 8 kN / m or more and 28 kN / m or less when measured in accordance with JIS K6252.

[0010] Furthermore, the light-transmitting rubber preferably has a Shore A hardness of 50 or more and 80 or less when measured with a Type A durometer in accordance with JIS K6253, a total light transmittance of 90% or more when measured in accordance with JIS K7136, a haze value of 1% or more and 7% or less, an elongation at break of 40% or more and 100% or less when measured in accordance with JIS K6251, and a tear strength (crescent type) of 5 kN / m or more and 10 kN / m or less when measured in accordance with JIS K6252.

[0011] In order to solve the above problems, the present invention provides a method for manufacturing an anti-spy sheet according to claim 1 or 2, The light-transmitting rubber is formed from a light-transmitting silicone rubber sheet, a plurality of silicone rubber sheets for the light-transmitting band and silicone rubber sheets for the light-shielding band are alternately stacked to form a laminate, the laminate is pressurized and then cut to form a louver layer sheet, opposing holes are formed in the louver layer sheet, and the light-transmitting rubber is fitted into the opposing holes.

[0012] In addition, silicone rubber for the silicone mirror layer is applied to the separator, this silicone rubber is laminated on one side of the louver layer sheet with light-transmitting rubber, adhesive is applied to the resin film layer, and this adhesive is laminated on the other side of the louver layer sheet with light-transmitting rubber to form a multilayer sheet body, and heat is applied to this multilayer sheet body to harden the silicone rubber for the silicone mirror layer and the adhesive, and then the multilayer sheet body can be cut to a specified shape based on the light-transmitting rubber.

[0013] Here, the term "portable information device" in the claims includes at least various multi-function mobile phones, such as smartphones. Furthermore, the term "authentication sensor" includes at least a face authentication sensor, an iris authentication sensor, an eye blood vessel authentication sensor, etc. Each numerical value may include measurement error as well as different numerical values, provided that there is no difference in the effects of the present invention.

[0014] The up, down, front, back, left and right directions of the anti-spy sheet according to the present invention are directions based on the drawings and can be changed as needed. Furthermore, although the subject of the present invention is an anti-spy sheet, if the configuration for other uses is the same as the configuration of the present invention and can be converted into an anti-spy sheet, and if the function and effect of the present invention are achieved, the configuration for other uses falls within the technical scope of the present invention.

[0015] According to the present invention, the light-transmitting rubber is fitted into the facing hole facing the authentication sensor in the louver layer, thereby preventing foreign matter such as dust from entering the facing hole of the anti-spy sheet from the outside. Furthermore, since the louver layer and the light-transmitting rubber are each made of soft silicone rubber and have flexibility, it is possible to prevent gaps from occurring between the facing hole and the light-transmitting rubber. [Effects of the Invention]

[0016] According to the present invention, by preventing foreign matter such as dust from entering the inside of the anti-spy sheet, it is possible to prevent contamination of the anti-spy sheet and eliminate the risk of functional degradation of the authentication sensor.

[0017] According to the invention of claim 2, the mildly adhesive silicone mirror layer is in close contact with the operation screen of the portable information device, preventing the anti-peeping sheet from shifting or falling off. Furthermore, the resin film layer covers and protects the louver layer when the operation screen of the portable information device is operated, preventing the louver layer from being damaged by contact with fingertips, etc. Furthermore, a resin film layer that covers the counter holes and light-transmitting rubber is laminated on the louver layer, preventing foreign matter such as dust from entering the counter holes.

[0018] According to the invention described in claim 3, by adhering a light-transmitting protective plate to the adhesive layer, damage to the louver layer can be prevented, and by adhering a glossy hard glass plate or hard resin sheet, etc., improved design can be expected.

[0019] According to the invention described in claim 4, the silicone rubber of the louver layer has a tensile strength of 7.5 MPa or more and 13.5 MPa or less when measured in accordance with JIS K6251, an elongation at break of 270% or more and 490% or less when measured in accordance with JIS K6251, and a tear strength of 8 kN / m or more and 28 kN / m or less when measured in accordance with JIS K6252, making it possible to satisfy the mechanical properties of the louver layer.

[0020] According to the invention of claim 5, the Shore A hardness of the light-transmitting rubber is between 50 and 80, which makes it possible to eliminate the risk of the light-transmitting rubber becoming difficult to handle or distorting in shape. In addition, the total light transmittance of the light-transmitting rubber is 90% or more, and the haze value of the light-transmitting rubber is between 1% and 7%, which is expected to prevent malfunction of the authentication sensor.

[0021] According to the invention of claim 6, since the light-transmitting rubber is formed by punching or cutting a flexible silicone rubber sheet, it is possible to easily obtain light-transmitting rubber of any size and shape. Furthermore, since the louver layer sheet is formed by cutting after pressing the laminate, it is possible to easily obtain multiple louver layer sheets. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a plan view illustrating an embodiment of an anti-snooping sheet according to the present invention; [Figure 2] 1 is an explanatory diagram showing a state in which a cutting die is pressed against a transparent silicone rubber sheet for a transparent window frame in an embodiment of a method for manufacturing an anti-spy sheet according to the present invention. FIG. [Figure 3] 1 is an explanatory diagram schematically illustrating a transparent window frame in an embodiment of an anti-spy sheet and a manufacturing method thereof according to the present invention. [Figure 4] 1 is an explanatory diagram showing a state in which a die is pressed against a location in a louver layer sheet where opposing holes are to be formed in the embodiment of the method for manufacturing an anti-spy sheet according to the present invention. FIG. [Figure 5] 5 is an explanatory view schematically showing a state in which opposing holes are punched in the louver layer sheet of FIG. 4. FIG. [Figure 6] 6 is an explanatory view showing a schematic view of a state in which a transparent window frame is inserted into the opposing hole in FIG. 5. FIG. [Figure 7] 1 is an explanatory diagram schematically showing a multilayer sheet body in an embodiment of a method for manufacturing an anti-snooping sheet according to the present invention. [Figure 8] 1 is an explanatory diagram schematically illustrating an embodiment of an anti-snooping sheet according to the present invention. [Figure 9] 3 is an explanatory view schematically showing a state in which a multilayer sheet body is punched in an embodiment of a method for manufacturing an anti-snooping sheet according to the present invention. FIG. [Figure 10] FIG. 10 is an explanatory diagram showing a schematic diagram of an anti-snooping sheet with a separator that has been punched out and completed. [Figure 11] FIG. 2 is an explanatory diagram schematically showing a second embodiment of the anti-snooping sheet according to the present invention. [Figure 12] FIG. 1 is a plan view illustrating a conventional anti-spy sheet. DETAILED DESCRIPTION OF THE INVENTION

[0023] A preferred embodiment of the present invention will now be described with reference to the drawings. As shown in Figures 1 and 8, the anti-spy sheet 10 in this embodiment is a sheet that is laminated on the surface 2, which is the operation screen of the smartphone 1, to control the viewing angle within a predetermined range. The anti-spy sheet 10 has a multi-layer structure that includes a louver layer 11 that faces the entire surface 2 of the smartphone 1, a transparent window frame 15 that is fitted into an opposing hole 14 in the louver layer 11 that faces the face recognition sensor of the smartphone 1, a light-transmitting silicone mirror layer 16 that is laminated on the back of the louver layer 11 and can be adhered to the surface 2 of the smartphone 1, and a light-transmitting resin film layer 18 that is adhered to the surface of the louver layer 11, and contributes to the achievement of Goal 9 of the SDGs adopted at the United Nations Summit.

[0024] As partially shown in FIG. 8, the smartphone 1 comprises a vertically long back panel on which a circuit board or the like is mounted, and a vertically long front panel that is attached to the opening of the back panel. Most of the front panel is formed as a capacitive operation screen, and the top of the front panel is equipped with a horizontally long, rectangular face authentication sensor that captures an image of the owner's face with a camera and contributes to the screen unlock function.

[0025] 1, the louver layer 11 is formed into a flexible rectangular shape with a symmetrical front and back planar shape in which a plurality of light-transmitting bands 12 and light-shielding bands 13 are arranged, and is formed to correspond to the size and shape of the smartphone 1. From the viewpoint of reducing the risk of information leakage, this louver layer 11 functions to control the visible angle to within a range of 15° to 70°, preferably 20° to 60°, and more preferably 40° to 60°.

[0026] The louver layer 11 is formed by repeatedly arranging multiple light-transmitting zones 12 and light-shielding zones 13 alternately in a row, with the pitch from each light-transmitting zone 12 to the adjacent light-shielding zone 13 set to 52 μm or more and 141 μm or less, and the thickness is 0.08 mm or more and 3.15 mm or less, preferably 0.12 mm or more and 1.38 mm or less, and more preferably 0.12 mm or more and 0.46 mm or less. The thickness of the louver layer 11 is 0.080 mm or more and 3.15 mm or less because, within this range, the visible angle can be easily adjusted and the layer can be easily manufactured.

[0027] In the louver layer 11, each light-transmitting band 12 is formed from transparent silicone rubber that has excellent heat resistance of 90°C or more, cold resistance, moisture resistance, environmental resistance, flexibility, transparency, etc., and helps prevent warping and deformation, and each shading band 13 is formed from transparent silicone rubber that has been colored to block light, and these light-transmitting bands 12 and shading bands 13 are formed at the same height, making the front and back symmetrical.

[0028] Examples of silicone rubber include silicone rubber compositions generally called millable rubber, which are composed of diorganopolysiloxanes whose molecular chain ends are blocked with hydroxysilyl or vinylsilyl groups and organic peroxides; and so-called addition reaction type organosilicone rubber compositions, which are composed of diorganopolysiloxanes having at least two vinyl groups bonded to silicon atoms in the molecule, organohydrogenpolysiloxanes having at least three hydrogen atoms bonded to silicon atoms (i.e., SiH bonds) in the molecule, and platinum catalysts. Specific examples of silicone rubber include KE-153U (product name, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0029] Silicone rubber has a density of 1.21 g / cm when measured at 23°C in accordance with JIS K6268. 3 More than 1.25g / cm 3 or less, preferably 1.24 g / cm 3Furthermore, from the viewpoint of preventing warping and deformation of the anti-spy sheet 10, the Shore A hardness measured with a rubber / plastic hardness tester, which is a Type A durometer in accordance with JIS K6253, is preferably 73 to 83, and more preferably 74 to 80. Furthermore, from the viewpoint of preventing warping and deformation, the tensile strength measured in accordance with JIS K6251 is preferably 7.5 MPa to 13.5 MPa, and more preferably 10 MPa to 12 MPa, and more preferably around 11 MPa.

[0030] From the viewpoint of satisfying mechanical properties, silicone rubber should have an elongation at break of 270% to 490%, preferably 360% to 430%, as measured in accordance with JIS K6251. To prevent warping and deformation, the tear strength (crescent type) should be 8 kN / m to 28 kN / m, preferably 20 kN / m to 26 kN / m, as measured in accordance with JIS K6252. These measurements can be performed using measuring instruments and testing machines from M&K Corporation, IT-S Japan Co., Ltd., and other companies.

[0031] Each light transmission band 12 is made of transparent silicone rubber and is formed into a vertically long rectangular cross section, and transmits light rays from the smartphone 1. From the viewpoint of achieving both anti-peeping and visibility, the light transmission band width of this light transmission band 12 is set in design to be 37 μm or more and 126 μm or less, preferably 45 μm or more and 115 μm or less, and more preferably around 45 μm, 60 μm, 95 μm, or 115 μm.

[0032] Each light-shielding band 13 is made of silicone rubber colored to provide light-shielding properties and has a rectangular cross section that is longer than the light-transmitting band 12 and is thinner than the light-transmitting band 12. The silicone rubber has the light-shielding color due to the addition of a colorant such as a pigment or dye to the type of silicone rubber used for the light-transmitting band, which has the above-mentioned physical properties. Specific examples of colorants include common organic or inorganic pigments such as carbon black, iron oxide, titanium oxide, yellow iron oxide, disazo yellow, and phthalocyanine blue, with black carbon black being the most suitable, due to its excellent light-shielding properties. If a black pigment is not used as the colorant, it is preferable to use a white pigment in combination to ensure light-shielding properties. Furthermore, the colorants may be used alone or in combination.

[0033] The shading zone 13 is set to the same height as the adjacent light transmitting zone 12, but in order to reliably prevent light leakage, the width of the shading zone is set to 10 μm or more, preferably 10 μm or more and 20 μm or less, more preferably 15 μm or more and 20 μm or less, and even more preferably 15 μm, taking into account tolerances.

[0034] 1, an opposing hole 14 that faces the face authentication sensor of the smartphone 1 is drilled through the upper part of the louver layer 11. This opposing hole 14 is formed in a horizontally long rectangle, similar to the face authentication sensor.

[0035] As shown in Figure 1, the transparent window frame 15 is formed into a flexible, horizontally elongated rectangle from transparent silicone rubber that has excellent heat resistance (over 90°C), cold resistance, moisture resistance, environmental resistance, flexibility, and high transparency, and that helps prevent warping and deformation. It is fitted into the opposing holes 14 of the anti-spy sheet 10 to prevent the intrusion of foreign matter such as dust. This transparent window frame 15 has a Shore A hardness measured with a Type A durometer in accordance with JIS K6253 of 50 to 80, preferably 55 to 70, and more preferably 58 to 65. This is because, for example, a Shore A hardness of 30 or less may result in poor handling during manufacturing operations, or the transparent window frame 15 may be easily deformed, resulting in a distorted shape.

[0036] In order to prevent malfunction of the face recognition sensor, the total light transmittance of the transparent window frame 15 is set to 90% or more, preferably 90% to 100%, more preferably 91% to 99%, and even more preferably 91% to 94%, when measured in accordance with JIS K7136. In addition, in order to prevent malfunction of the face recognition sensor, the haze value of the transparent window frame 15 is optimally set to 1% to 7%, preferably 1% to 5%, and more preferably 1.6% to 3%, when measured in accordance with JIS K7136.

[0037] From the viewpoint of satisfying mechanical properties, the elongation at break of the transparent window frame 15 is optimally 40% to 100%, preferably 70% to 95%, when measured in accordance with JIS K6251. Furthermore, the tear strength (crescent shape) when measured in accordance with JIS K6252 is optimally 5 kN / m to 10 kN / m, preferably 7 kN / m to 9.5 kN / m, to prevent warping and deformation. Examples of silicone rubbers that can be used to form such transparent window frames 15 include the highly transparent material KE-2061-60-A / B (product name, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0038] 8, the silicone mirror layer 16 is formed from a slightly adhesive, transparent silicone rubber that has excellent heat resistance of 90°C or more, cold resistance, moisture resistance, environmental resistance, flexibility, transparency, etc., and helps prevent warping and deformation, and is mirror-finished to improve transparency and adhesiveness at least on the surface to be laminated on the front surface 2 of the smartphone 1, and is laminated on the back surface of the louver layer 11. The thickness of this silicone mirror layer 16 is not particularly limited, but is, for example, about 30 μm.

[0039] Such silicone mirror layer 16 is covered and protected by a peelable separator 17 until it is adhered to the surface 2 of the smartphone 1, and when it is adhered to the surface 2 of the smartphone 1, the separator 17 is peeled off and adheres detachably to the surface 2 of the smartphone 1, functioning to prevent displacement or falling off of the anti-spy sheet 10. The separator 17 is not particularly limited, but for example, a transparent polyethylene terephthalate (PET) resin film, which has excellent heat resistance, strength, etc., is used.

[0040] 8, the resin film layer 18 is made of, for example, a transparent polyethylene terephthalate resin film with a thickness of approximately 188 μm, which has excellent heat resistance and strength, and is adhered to the surface of the louver layer 11 via a silicone adhesive 19, thereby functioning to cover and protect the louver layer 11. Specific examples of the silicone adhesive 19 include KE-1825 (product name, manufactured by Shin-Etsu Chemical Co., Ltd.) and KE-1056 (product name, manufactured by Shin-Etsu Chemical Co., Ltd.), and the thickness of the adhesive layer when dried and hardened is adjusted to approximately 30 μm.

[0041] In the above, when manufacturing the anti-spy sheet 10, first, a transparent silicone rubber sheet 20 for the transparent window frame 15 is prepared (see FIG. 2), and a dedicated die 21 is pressed against this transparent silicone rubber sheet 20 to form the transparent window frame 15 (see FIG. 3). The transparent silicone rubber sheet 20 may be formed by filling a mold with a liquid transparent silicone rubber sheet, or a commercially available product may be used.

[0042] Next, a plurality of transparent silicone rubber sheets for the light transmission band and a plurality of black-colored silicone rubber sheets for the light-shading band are prepared, and these plurality of silicone rubber sheets for the light transmission band and the light-shading band are alternately laminated to form a laminate. The silicone rubber sheets for the light transmission band and the light-shading band can be manufactured by extrusion molding, calendar molding, or press molding. The silicone rubber sheets for the light transmission band and the light-shading band are preferably bonded by thermocompression, but they may also be alternately laminated and bonded with a silicone-based transparent adhesive, which is expected to provide reliable adhesion.

[0043] Next, the laminate is heated and pressurized to form a block body, and this block body is cut downward from the side at a predetermined thickness to form a sheet-shaped louver layer sheet 22. A special punching die 23 is pressed against the location where the opposing holes are to be formed in this louver layer sheet 22 (see Figure 4) to drill opposing holes 14 (see Figure 5), and then a transparent window frame 15 is inserted into the opposing holes 14 without any gaps (see Figure 6).

[0044] Next, silicone rubber 24 for the silicone mirror layer is printed on separator 17, and this silicone rubber 24 is laminated onto one side of louver layer sheet 22 with transparent window frame 15 (see Figure 7). After silicone rubber 24 has been laminated onto louver layer sheet 22 in this way, silicone adhesive 19 is printed on resin film layer 18, and this silicone adhesive 19 is laminated onto the other side of louver layer sheet 22 with transparent window frame 15 to form multilayer sheet body 25 (see Figure 7), and heat of about 120°C is applied to multilayer sheet body 25 to cure silicone rubber 24 for the silicone mirror layer and silicone adhesive 19 (see Figure 7).

[0045] Then, in order to properly position the face authentication sensor of the smartphone 1 and the transparent window frame 15, a special die 26 is pressed against the multilayer sheet body 25 using the transparent window frame 15 as a reference, and the multilayer sheet body 25 is punched out to a predetermined size and shape (see Figure 9), thereby producing the anti-peeping sheet 10 with separator 17 shown in Figure 10.

[0046] As described above, the transparent window frame 15 is tightly fitted without any gaps into the facing hole 14 of the louver layer 11 that faces the face authentication sensor, and further, the resin film layer 18 that covers the facing hole 14 and the transparent window frame 15 is laminated on the surface of the louver layer 11, so it is possible to prevent foreign matter such as dust from entering the facing hole 14 of the anti-spy sheet 10. Therefore, it is possible to eliminate the risk of the anti-spy sheet 10 becoming dirty or the face authentication sensor malfunctioning due to contamination.

[0047] Moreover, since both the louver layer 11 and the transparent window frame 15 are made of flexible silicone rubber and have flexibility, the opposing holes 14 can be filled without gaps even if the smartphone 1 is warped. Furthermore, the presence of the transparent window frame 15 can prevent the resin film layer 18 from being partially recessed at the opposing holes 14, preventing a deterioration in the design.

[0048] Next, Figure 11 shows a second embodiment of the present invention, in which a light-transmitting adhesive layer 30 is laminated on a resin film layer 18, and a protective hard glass plate (not shown) is adhered to this adhesive layer 30.

[0049] The adhesive layer 30 is not particularly limited, but may be made of, for example, a light-transmitting acrylic tape having a thickness of about 25 μm. This adhesive layer 30 is covered and protected by a removable separator 31 until the hard glass plate is adhered thereto. After that, the separator 31 is peeled off and the high-hardness glass plate is adhered thereto. A specific example of the acrylic tape is CS9862 US (product name, manufactured by Nitto Denko Corporation). The separator 31 may be, for example, a transparent polyethylene terephthalate resin film, which has excellent heat resistance and strength. The other parts are the same as those in the above embodiment, so a description thereof will be omitted.

[0050] In this embodiment, the same effects as those of the above embodiment can be expected, and it is clear that the design can be improved by using a glossy, light-transmitting hard glass plate and adhering it to the glass.

[0051] In the above embodiment, the opposing holes 14 are formed in the upper part of the louver layer 11 in the shape of a horizontally elongated rectangle, but this is not limited to this and the opposing holes 14 may be formed in a rectangular, polygonal, circular, elliptical, or other shape depending on the shape of the face authentication sensor. Also, the opposing holes 14 may be formed in the lower or side part of the louver layer 11 depending on the position of the face authentication sensor. Furthermore, although a polyethylene terephthalate resin film is used as the resin film layer 18, this is not limited to this and a transparent polycarbonate resin film that is resistant to warping and deformation may also be used.

[0052] Furthermore, the manufacturing method of the above embodiment is not limited to the order described. For example, the louver layer 11 may be formed before the transparent window frame 15 is formed, or the transparent window frame 15 and the louver layer 11 may be formed simultaneously. Furthermore, all of the technologies described in this specification are subject to patent rights through amendments or divisional applications, etc. [Example]

[0053] Hereinafter, examples of the anti-spy sheet and the manufacturing method thereof according to the present invention will be described together with comparative examples. Example 1 Liquid transparent silicone rubber (product name KE-2061-60-A / B, manufactured by Shin-Etsu Chemical Co., Ltd.) was filled into a mold to form a transparent silicone rubber sheet, which was then pressed against a special die to form a transparent window frame. The transparent silicone rubber sheet was molded to a size of approximately 200 mm x 200 mm x 0.32 mm.

[0054] The transparent window frame had a Shore A hardness of 59 measured with a Type A durometer in accordance with JIS K6253, a total light transmittance of 91.78% measured in accordance with JIS K7136, a haze value of 1.78% measured in accordance with JIS K7136, an elongation at break of 90% measured in accordance with JIS K6251, and a tear strength (crescent type) of 9 kN / m measured in accordance with JIS K6252.

[0055] Next, several transparent silicone rubber sheets for the light transmission band and several black-colored silicone rubber sheets for the light-shading band were prepared, and these several silicone rubber sheets for the light transmission band and the light-shading band were alternately stacked and thermocompression bonded to form a laminate. The silicone rubber sheets for the light transmission band and the silicone rubber sheets for the light-shading band were molded by filling a mold with transparent silicone rubber (product name KE-153U, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0056] These silicone rubber sheets had a Shore A hardness of 76 measured with a Type A durometer in accordance with JIS K6253, a tensile strength of 11 MPa measured in accordance with JIS K6251, an elongation at break of 420% measured in accordance with JIS K6251, and a tear strength (crescent type) of 24 kN / m measured in accordance with JIS K6252.

[0057] After constructing the laminate, the laminate was heated and pressurized to form a block, which was then cut downward from the side to a thickness of 0.32 mm to form louver layer sheets, and a special cutting die was pressed against the locations where opposing holes were to be formed in the louver layer sheet to drill opposing holes, after which a 0.32 mm thick transparent window frame was inserted tightly into the opposing holes.When the louver layer sheet was examined, it showed a pitch of 0.132, a viewing angle of 60°, and a louver angle of 0°.

[0058] Next, a transparent polyethylene terephthalate resin film (manufactured by Toray Industries, Inc.: product name: Lumirror Polymer Coat P0.1T) was prepared as a separator, and silicone rubber for the silicone mirror layer was printed on this polyethylene terephthalate resin film. This silicone rubber was then laminated to the back surface of the louver layer sheet with a transparent window frame.

[0059] After the silicone rubber was laminated onto the louver layer sheet, a silicone adhesive was printed onto the resin film layer, and this silicone adhesive was laminated onto the surface of the louver layer sheet with a transparent window frame to form a multilayer sheet. This multilayer sheet was then heated to 120°C to cure the silicone rubber for the silicone mirror layer and the silicone adhesive. The resin film layer was made of a transparent polyethylene terephthalate resin film (manufactured by Kimoto Co., Ltd.: product name KB Film 188G01S). The silicone adhesive used was KE-1056 (manufactured by Shin-Etsu Chemical Co., Ltd.: product name).

[0060] Thereafter, a special die was pressed against the multilayer sheet body using the transparent window frame as a reference, and the sheet was punched out into a predetermined size and shape to produce an anti-spy sheet for iPhone (registered trademark) as shown in FIG. After manufacturing the anti-spy sheet in this way, the polyethylene terephthalate resin film of the separator was peeled off and the anti-spy sheet was adhered to the operation screen of an iPhone. The transparent window frame was tightly fitted into the facing hole without any gaps, and the facing hole and transparent window frame were covered and protected by the resin film layer, so it is assumed that foreign objects such as dust can be prevented from entering the facing hole of the anti-spy sheet. In addition, when we tested whether the iPhone's facial recognition sensor was working properly, we were able to operate the iPhone freely, so it is assumed that the facial recognition sensor was working properly.

[0061] Comparative Example 1 Liquid transparent silicone rubber (product name KE-2061-30-A / B, manufactured by Shin-Etsu Chemical Co., Ltd.) was filled into a mold to form a transparent silicone rubber sheet, which was then pressed against a special die to form a transparent window frame. The transparent silicone rubber sheet was molded to a size of approximately 200 mm x 200 mm x 0.32 mm.

[0062] The transparent window frame had a Shore A hardness of 30 measured with a Type A durometer in accordance with JIS K6253, a total light transmittance of 92.18% measured in accordance with JIS K7136, a haze value of 1.54% measured in accordance with JIS K7136, an elongation at break of 350% measured in accordance with JIS K6251, and a tear strength (crescent type) of 3 kN / m measured in accordance with JIS K6252.

[0063] An anti-spy sheet for iPhone was manufactured in the same manner as in Example 1. The polyethylene terephthalate resin film separator was then peeled off and the anti-spy sheet was adhered to the iPhone's operation screen. The transparent window frame had a Shore A hardness of 30, an elongation at break of 350%, and a tear strength of 3 kN / m, making it more flexible and prone to deformation than necessary, making it difficult to fit the transparent window frame tightly into the opposing hole without any gaps, which hindered the manufacturing process.

[0064] Comparative Example 2 A resin sheet made of polycarbonate resin was prepared and a special die was pressed against the resin sheet to form a transparent window frame. This transparent window frame had a total light transmittance of 90.16% as measured in accordance with JIS K7136, and a haze value of 0.01%, also measured in accordance with JIS K7136.

[0065] An anti-spy sheet for iPhone was manufactured in the same manner as in Example 1. Then, the polyethylene terephthalate resin film of the separator was peeled off and the anti-spy sheet was adhered to the operation screen of the iPhone. Because a transparent window frame made of a hard polycarbonate resin sheet was used, air bubbles occurred in the assembly part when the transparent window frame was tightly fitted into the opposing hole, which hindered the manufacturing process.

[0066] Comparative Example 3 The type of liquid transparent silicone rubber was changed to KE-1950-60-A / B (product name, manufactured by Shin-Etsu Chemical Co., Ltd.), and this changed transparent silicone rubber was filled into a mold to form a transparent silicone rubber sheet. A special cutting die was then pressed against this transparent silicone rubber sheet to form a transparent window frame.

[0067] The transparent silicone rubber sheet was molded to a size of approximately 200 mm x 200 mm x 0.32 mm. The transparent window frame had a total light transmittance of 88.76%, less than 90%, measured in accordance with JIS K7136, and a haze value of 25.86%, greater than 7%, measured in accordance with JIS K7136.

[0068] An anti-spy sheet for iPhone was manufactured in the same manner as in Example 1, after which the polyethylene terephthalate resin film of the separator was peeled off and the anti-spy sheet was adhered to the operation screen of the iPhone. The transparent window frame was tightly fitted into the opposing hole without any gaps, and the opposing hole and transparent window frame were covered and protected by the resin film, which is presumably why foreign matter such as dust can be prevented from entering the opposing hole of the anti-spy sheet. However, when we tested whether the iPhone's facial recognition sensor was working properly, we found that it caused serious problems with the operation of the iPhone, so we believe that the facial recognition sensor was malfunctioning. [Industrial Applicability]

[0069] The anti-spy sheet and the method for producing the same according to the present invention are used in the field of portable information devices such as smartphones. [Explanation of symbols]

[0070] 1. Smartphones (mobile information devices) 2 Surface (operation screen) 10. Anti-peeping sheet 11 Louver Layer 12 Light transmission band 13 Shade strip 14 Opposing holes 15 Transparent window frame (light-transmitting rubber) 16 Silicone mirror layer 18 Resin film layer 19 Silicone adhesive 20 Transparent silicone rubber sheet 22 Louver layer sheet 24 Silicone rubber 25 Multilayer sheet body 30 Adhesive layer

Claims

1. An anti-peeping sheet that is laminated on an operation screen of a portable information device and controls the visible angle within a predetermined range, The anti-peeping sheet comprises a louver layer facing the operation screen of a portable information device with a plurality of light-transmitting bands and light-blocking bands arranged alternately, and light-transmitting rubber fitted into an opposing hole in the louver layer facing the authentication sensor of the operation screen of the portable information device, wherein the light-transmitting bands and light-transmitting rubber of the louver layer are each formed from light-transmitting silicone rubber, and the light-blocking bands of the louver layer are formed from colored silicone rubber.

2. The anti-spy sheet according to claim 1, comprising a light-transmitting silicone mirror layer laminated on one side of the louver layer and adhesive to the operating screen of a portable information device, and a light-transmitting resin film layer adhered to the other side of the louver layer.

3. 3. The anti-snooping sheet according to claim 2, which comprises a light-transmitting adhesive layer laminated on the resin film layer.

4. The silicone rubber of the louver layer has a tensile strength of 7.5 MPa or more and 13.5 MPa or less when measured in accordance with JIS K6251, an elongation at break of 270% or more and 490% or less when measured in accordance with JIS K6251, and a tear strength of 8 kN / m or more and 28 kN / m or less when measured in accordance with JIS K6252.

5. The light-transmitting rubber has a Shore A hardness of 50 to 80 when measured with a Type A durometer in accordance with JIS K6253, a total light transmittance of 90% or more when measured in accordance with JIS K7136, a haze value of 1% to 7%, an elongation at break of 40% to 100% when measured in accordance with JIS K6251, and a tear strength (crescent shape) of 5 kN / m to 10 kN / m when measured in accordance with JIS K6252.

6. A method for manufacturing an anti-peeping sheet as described in claim 1 or 2, characterized in that a light-transmitting rubber is formed from a light-transmitting silicone rubber sheet, a plurality of silicone rubber sheets for the light-transmitting band and a silicone rubber sheet for the light-shielding band are alternately stacked to form a laminate, the laminate is pressurized and then cut to form a louver layer sheet, opposing holes are made in the louver layer sheet, and the light-transmitting rubber is inserted into the opposing holes.

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