CN210072116U

CN210072116U - Louvered film

Info

Publication number: CN210072116U
Application number: CN201790001426.6U
Authority: CN
Inventors: 岩间进; 泷泽直也
Original assignee: Shin Etsu Polymer Co Ltd
Current assignee: Shin Etsu Polymer Co Ltd; Shin Etsu Chemical Co Ltd
Priority date: 2016-11-29
Filing date: 2017-11-29
Publication date: 2020-02-14
Anticipated expiration: 2027-11-29
Also published as: TW201827862A; WO2018101325A1; JP7153763B2; JP2018087899A; JP2021119402A

Abstract

The utility model discloses a tripe formula membrane (1), tripe formula membrane (1) possesses louver layer (10) that printing opacity area (11) and shading area (12) dispose in turn, and the interval of shading area (12) is more than 300 mu m and below 1100 mu m.

Description

Louvered film

Technical Field

The present invention relates to a louver film which is suitable for a light transmitting window such as a window of a building or a front windshield of an automobile, or a head-up display, and which blocks transmission of a part of light incident on the light transmitting window.

The present application claims priority based on the 2016-230999 patent application, filed in japan on 29/11/2016, and the contents of which are incorporated herein by reference.

Background

Conventionally, a louver having metal blades arranged therein is provided on an indoor side of a window glass to adjust an amount of light incident from the outside. There is an advantage that the amount of light can be easily adjusted by adjusting the louver angle of the louver, but on the other hand, the louver is generally thicker than the window glass, and there is a problem that a sense of pressure is given to the space inside the room. Further, when the light-transmitting window is curved or inclined, it is difficult to provide the conventional louver along the state of the light-transmitting window.

Therefore, the present invention has been made in view of the fact that, if a transparent film which can be closely attached to a light transmission window has a function of a louver, the present invention can be applied to a place where it is difficult to install a conventional louver, and an application of a light emission direction control plate which is used for preventing peeking by being attached to a conventional liquid crystal display screen (see, for example, patent document 1) is considered.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2006-337837

SUMMERY OF THE UTILITY MODEL

However, when a conventional light emission direction control film is attached to a light transmitting window and an external landscape is viewed from the indoor side, a problem arises in that a double image in which a plurality of objects to be viewed are superimposed is seen. The researchers of the present invention have further examined and found that this phenomenon is not a phenomenon of the physiology of the observer, but a physical phenomenon in which the light exit direction control film functions as a diffraction grating.

The utility model discloses in view of the circumstances forms, provides a setting and can not see the ghost image that sees the visual object thing that sees through the light transmission window when the light transmission window, does not hinder the seeing through of the light that incides in the light transmission window from specific direction, hinders the tripe formula membrane of seeing through of the light that incides in the light transmission window from outside this specific direction.

[1] The louver film is characterized in that the pitch of the shading bands is more than 300 mu m and less than 1100 mu m.

[2] [1] the louver film is characterized in that the aperture ratio represented by { the width of the light-transmitting band/(the width of the light-transmitting band + the width of the light-shielding band) } × 100% is 90% or more and 99.9% or less.

[3] [1] the louver film according to [1] or [2], wherein the thickness of the louver layer is 350 μm or more and 3000 μm or less.

[4] [1] the louver film according to any one of [1] to [3], wherein the width of the light-transmitting band is 270 μm or more and 1098 μm or less.

[5] [1] the louver film according to any one of [1] to [4], wherein the width of the light-shielding tape is 1 μm or more and 100 μm or less.

[6] [1] the louver film according to any one of [1] to [5], wherein a ratio represented by [ a width of the light-shielding tape ]/[ a width of the light-transmitting tape ] is 0.005 to 0.5.

[7] [1] the louver film according to any one of [1] to [6], wherein the louver layer has a length of 1cm to 1000cm and a width of 1cm to 1000cm in a plan view.

[8] The louver film according to any one of [1] to [7], wherein a transparent protective layer is provided on at least one of a front surface and a back surface of the louver layer.

Preferably, the louver film is characterized in that the pitch of the light-shielding tape is 300 μm or more and 500 μm or less.

Preferably, the louver film is characterized in that the pitch of the light-shielding tape is 350 μm or more and 500 μm or less.

Preferably, the louver film is characterized in that the widths of the light-shielding tapes are uniform and fixed in the longitudinal direction.

Preferably, the louver film is characterized in that a ratio of the width of the light-shielding tape/the width of the light-transmitting tape is 0.005 or more and 0.5 or less.

Preferably, in a cross section in a thickness direction of the louver layer, an orientation of a side of the light-shielding tape in the thickness direction is parallel to the thickness direction of the louver layer.

Preferably, in a cross section in a thickness direction of the louver layer, an orientation of a side of the light-shielding tape in the thickness direction is inclined with respect to the thickness direction of the louver layer.

Preferably, the louver film has a rectangular planar shape, and the rectangle has a length of 1cm or more and 1000cm or less and a width of 1cm or more and 1000cm or less.

Effect of the utility model

According to the utility model discloses a tripe formula membrane sets up the ghost image that can not see the visual object thing that sees through the light trap when the light trap, does not obstruct the seeing through of the light of inciding in the light trap from specific direction, can restrain the seeing through of the light of inciding in the light trap from outside this specific direction. This makes it possible to adjust the amount of light incident from the light-transmitting window, prevent peeping from the outside into the room, and make it difficult to confirm the display from a display provided at a position distant from the light-transmitting window from a predetermined direction.

Drawings

Fig. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG. 1.

Fig. 3 shows an example of a method of using the louver film according to the present invention.

Fig. 4 shows another example of a method of using the louver film according to the present invention.

Detailed Description

< first embodiment >

Fig. 1 and 2 are views showing a first embodiment of the louver film of the present invention, fig. 1 is a perspective view, and fig. 2 is a cross-sectional view taken along the ii-ii line in fig. 1. In the drawings, a part of the louver film is schematically shown in an enlarged manner.

The louver film 1 of the present embodiment includes a louver layer 10 in which a plurality of light transmitting bands 11 and a plurality of light blocking bands 12 are alternately and repeatedly arranged, a first transparent protective layer 13 provided on the entire surface of the louver layer 10, and a second transparent protective layer 14 provided on the entire back surface of the louver layer 10.

The planar shape of the entire louver film 1 is rectangular, but the planar shape is not limited to rectangular, and can be changed as appropriate depending on the shape of the applicable light-transmitting window. Herein, "light transmissive window" means a limited two-dimensional area in any space through which light is transmitted. The two-dimensional region may be a plane or an arbitrary curved surface. A physical window substrate of light-permeable glass, plastic or the like may or may not be provided in the two-dimensional region. When the window base is not provided, the louver film preferably maintains its shape as a self-standing film. When the window base is provided, the shape in which the louver film is supported by the window base can be realized by closely adhering the louver film to the window base. The size of the louver film 1 is not particularly limited, and examples thereof include a size having a length of 1cm to 1000cm and a width of 1cm to 1000cm in a plan view, a size having a length of 30cm to 100cm and a width of 30cm to 100cm in a plan view, and the like. The thickness of the louver film 1 will be described later.

In the present embodiment, the thickness direction of the louver layer 10 is defined as the Z direction, the direction in which the light-transmitting tape 11 and the light-shielding tape 12 extend within a plane perpendicular to the Z direction is defined as the X direction, and the direction perpendicular to both the X direction and the Z direction is defined as the Y direction. The light-transmitting bands 11 and the light-blocking bands 12 constituting the louver layer 10 are both in a band shape extending in the X direction, and the plurality of light-transmitting bands 11 and the plurality of light-blocking bands 12 are alternately arranged in the Y direction. The width W1 in the Y direction of the plurality of light-transmitting tapes 11 is uniform and constant in the X direction. The widths W2 of the light-shielding tapes 12 in the Y direction are also uniform and constant in the X direction.

In the present embodiment, the pitch P of the light-shielding tapes 12 is the sum of the width W1 of the individual light-transmitting tapes 11 and the width W2 of the individual light-shielding tapes 12 in the Y direction.

The pitch of the light-shielding tape in the louver film is determined based on a cross-sectional view of the Y-Z plane of the cut louver layer 10, as shown in fig. 2. Specifically, when the cross section perpendicular to the longitudinal direction (X direction) of the light-transmitting belts 11 and the light-shielding belts 12 is observed with a digital microscope, the length in the Y direction is measured as the width W1 of the single light-transmitting belt 11 and the width W2 of the single light-shielding belt 12 adjacent to the light-transmitting belt 11 in the cross-sectional image, and the sum of the width W1 and the width W2 is the pitch P of the light-shielding belts 12.

As a material of the light transmitting tape 11, a resin material that transmits a wavelength of a target visible light can be used. The wavelength of light transmitted through the light-transmitting band 11 may be 380nm or more and 830nm or less of the entire range of visible light, or may be a part thereof. The resin material having high transparency is preferably a resin material having a light transmittance of 75% or more, preferably 85% or more, only when light enters the light transmitting tape 11 in the Z direction in the drawing. Specifically, thermoplastic resins or thermosetting resins having high transparency are exemplified, and examples thereof include cellulose resins, polyolefin resins, polyester resins, silicone resins, polystyrene resins, polyvinyl chloride resins, acrylic resins, polycarbonate resins, and the like. Among them, silicone resins are preferable, and silicone rubbers are particularly preferable because of their heat resistance and transparency. The upper limit of the light transmittance of the light-transmitting tape 11 is 100% or less.

The value of "light transmittance" in the present invention is D specified by JIS Z8720₆₅In an apparatus for measuring the intensity of inspection light emitted from a light source by a light-receiving sensor, when the output value of the light-receiving sensor in a state where no object to be inspected is present on the optical path of the inspection light is represented by A and the output value of the light-receiving sensor in a state where the object to be inspected is present on the optical path of the inspection light and the light-receiving sensor receives transmitted light transmitted through the object to be inspected is represented by B, the light transmittance is a value obtained by (B/A) × 100 (unit;).

As the material of the light-shielding tape 12, the resins listed above as the material of the light-transmitting tape 11 are used as a base material, and a colored resin to which a colorant such as a pigment or a dye is added is suitably used here.

In the louver layer 10, the resin material constituting the light transmitting tape 11 and the resin material constituting the base material of the light blocking tape 12 may be the same or different, but from the viewpoint of adhesiveness between the light transmitting tape 11 and the light blocking tape 12 と, it is preferable that both are the same.

The color tone of the light-shielding tape 12 may be such that satisfactory light-shielding properties can be obtained in the light-shielding tape 12, and may be, for example, black, red, yellow, green, blue, pale blue, or the like. The color tone of the light-shielding tape 12 can be adjusted by the type and amount of the colorant. Specifically, the light-shielding property is preferably 40% or less, more preferably 10% or less, in the Y direction in the figure when light enters only the light-shielding tape 12. The lower limit of the light transmittance of the light-shielding tape 12 is 0% or more.

The gloss value on the plane (X-Z plane) perpendicular to the Y direction of the light-shielding tape 12 can be evaluated as a value when the incident angle is 60 ° in JIS Z8741. In general, the lower the gloss value, the lower the reflection of light by the light-shielding tape 12 tends to be.

Since the color tone of the light-shielding tape 12 constitutes a color tone recognized when the louver layer 10 (louver film 1) is viewed, it is preferable to design in consideration of design performance.

Specific examples of the colorant include general organic pigments or inorganic pigments such as carbon black, red iron oxide, titanium oxide, yellow iron oxide, disazo yellow, and phthalocyanine blue. One kind of the colorant may be used, or two or more kinds thereof may be used. When a black pigment is not used, a white pigment is preferably used in combination in order to obtain good light-shielding properties.

The amount of the colorant added to the resin base material of the light-shielding tape 12 may be appropriately set in consideration of the above-mentioned circumstances, because sufficient light-shielding properties cannot be obtained when the amount is small, and deterioration in processability is remarkable when the amount is large. For example, the colorant may be added in an amount of 0.1 to 10% by mass based on the total mass of the resin base material of the light-shielding tape 12.

As shown in fig. 2, the pitch P of the light-shielding tapes 12 of the louver layer 10 is represented by (the width W1 of the light-transmitting tape 11 + the width W2 of the light-shielding tape 12). The pitch P of the light-shielding tape 12 is 300 μm or more and 1100 μm or less, preferably 350 μm or more and 900 μm or less, and more preferably 400 μm or more and 750 μm.

If the pitch is equal to or greater than the lower limit of the above range, the ghost phenomenon of the visible object can be sufficiently prevented from being seen.

If the pitch is equal to or smaller than the upper limit of the above range, the adjustment of the amount of light transmitted through the louver film 1 and the adjustment of the light transmission angle (visible angle) θ described later become easy. In general, the light quantity transmitted through the louver film 1 decreases as the pitch P becomes narrower, and the light transmission angle θ becomes narrower.

The light transmittance in the Z direction of the louver film 1 is preferably 50% or more and 90% or less, more preferably 60% or more and 88% or less, and still more preferably 65% or more and 85% or less, depending on the application.

The aperture ratio in the Y direction, which is expressed by { width W1 of light transmitting tape 11/(width W1 of light transmitting tape 11 + width W2 of light shielding tape 12) } × 100%, affects the transmittance of light incident on the louver layer 10 in the Z direction. In order to increase the transmittance, it is preferable to reduce the width W2 of the light-shielding tape 12, increase the width W1 of the light-transmitting tape 11, and increase the aperture ratio. On the other hand, in order to reduce the light transmittance of the louver layer 10, it is preferable to increase the width W2 of the light-shielding tape 12, reduce the width W1 of the light-transmitting tape 11, and reduce the aperture ratio in order to narrow the light transmission angle. From the viewpoint of further improving the visibility of the visible object passing through the light-transmitting window, the aperture ratio is preferably 90% or more and 99.9% or less, more preferably 91% or more and 99% or less, and still more preferably 93% or more and 98% or less.

In the louver layer 10, the width W1 of the light-transmitting band 11 in the Y direction is preferably 270 μm or more, more preferably 300 μm or more, and still more preferably 400 μm or more, from the viewpoint of suppressing a decrease in light transmittance and enlarging the light transmission angle θ. By setting the width W1 of the light-transmitting tape 11 in the above range, good light transmittance and light transmission angle θ of light in the louver layer 10 can be obtained. The upper limit of the width W1 of the light-transmitting band 11 may be, for example, about 1098 μm for the purpose of reducing the light transmittance so as to function as a louver and reducing the light transmission angle θ. Thus, for example, the width W1 ≦ 270 μm ≦ 1098 μm, more preferably the width W1 ≦ 1098 μm 300 μm, and still more preferably the width W1 ≦ 1098 μm 400 μm.

In the louver layer 10, the width W2 of the light-shielding tape 12 in the Y direction is preferably 100 μm or less, more preferably 50 μm or less, and still more preferably 30 μm or less, from the viewpoint of suppressing a decrease in light transmittance and enlarging the light transmission angle θ. By setting the width W2 of the light-shielding tape 12 within the above range, it is possible to obtain a favorable light transmittance and light transmission angle θ of the light in the louver layer 10. The lower limit of the width W2 of the light-shielding tape 12 may be about 1 μm in consideration of manufacturing limitations. Thus, for example, the width W2 is preferably 1 μm or less and 100 μm or less, the width W2 is more preferably 1 μm or less and 50 μm or less, and the width W2 is more preferably 1 μm or less and 30 μm or less.

The ratio of [ width W2 of light-shielding tape 12 ]/[ width W1 of light-transmitting tape 11 ] is, for example, preferably 0.005 to 0.5, more preferably 0.01 to 0.1.

The thickness T of the louver layer 10 in the Z direction is not particularly limited, and is, for example, preferably 350 μm or more and 3000 μm or less, more preferably 400 μm or more and 2000 μm or less, and still more preferably 500 μm or more and 1000 μm or less, from the viewpoint of suppressing the decrease in the light transmittance of the louver layer 10 and reducing the light transmission angle θ.

If the thickness is not less than the lower limit of the above range, the light transmittance can be reduced to function as a louver, and the light transmission angle θ can be reduced.

If the thickness is not more than the upper limit of the above range, sufficient light transmittance and light transmission angle θ can be obtained. In addition, the arrangement in the light transmissive window becomes easier.

In the present specification, "thickness" and "width" are values measured at five randomly selected places and averaged when a cross section of a measurement object is observed using a digital microscope, a magnifying glass, or a microscope.

As shown in fig. 2, the light transmission angle θ of the louver film 1 in the plane (Y-Z plane, paper plane in fig. 2) perpendicular to the X direction is the maximum value of the angle formed by the light rays passing through the back surface from the front surface of the single light transmitting band 11 of the louver film 1. The light transmission angle θ is determined by the thickness T of the louver layer 10 and the width W1 of the light-transmitting tape 11 in the Y direction. The thinner the thickness T of the louver layer 10 is, the larger the light transmission angle θ is, the larger the width W1 of the light-transmitting tape 11 is, and the larger the light transmission angle θ is.

Therefore, the thickness of the louver layer 10 is preferably designed to obtain a desired light transmission angle θ in consideration of the pitch P of the light-shielding tapes 12 and the width W2 of the light-shielding tapes 12.

For example, when the pitch P of the light-shielding tapes 12 is 500 μm and the width W2 of the light-shielding tapes 12 is 20 μm, the light transmission angle θ of about 100 ° can be obtained when the thickness T of the louver layer 10 is 740 μm.

The lower limit of the thickness T of the louver layer 10 is designed in consideration of the range of the preferable light transmission angle θ.

If the light transmission angle θ of the louver film is too small, the visible object passing through the opposite side of the light-transmitting window may be difficult to see. On the other hand, if the light transmission angle θ is too large, it may be difficult to adjust the amount of light incident from the light-transmitting window or to suppress peeping from the outside to the indoor side. The appropriate light transmission angle θ can be changed depending on the application of the louver film, but is preferably 30 ° or more and 150 ° or less, more preferably 45 ° or more and 140 ° or less, and further preferably 60 ° or more and 120 ° or less.

The light transmission angle θ of the louver film is determined based on a cross-sectional view of the Y-Z plane of the cut louver layer 10, as shown in fig. 2. Specifically, the cross section perpendicular to the longitudinal direction (X direction) of the light transmitting band 11 and the light blocking band 12 is observed with a digital microscope or the like, and in the cross-sectional image, the planar shape of the single light transmitting band 11 sandwiched between the two light blocking bands 12 is determined, and the angle of the diagonal line constituting the planar shape is the light transmission angle θ.

The louver layer 10 described above can be manufactured by the following method, for example. First, a plurality of first thin plates having a thickness of W1 and made of the material constituting the light-transmitting belt 11 and a plurality of second thin plates having a thickness of W2 and made of the material constituting the light-shielding belt 12 are alternately laminated, heated, and pressed to form a block in which these thin plates are integrated. Next, the surface of each of the stacked thin plates constituting the block is sliced perpendicularly to the cutting plane to obtain the louver layer 10. The thickness (slice width) at the time of slicing is T.

As the material of the first transparent protective layer 13 and the second transparent protective layer 14 provided on the front surface and the back surface of the louver layer 10, for example, the above-mentioned resin as the material of the light transmitting band 11 can be used. The light transmittance of the single first transparent protective layer 13 and the single second transparent protective layer 14 when light is transmitted in the thickness direction (Z direction in the drawing) of each layer is preferably 75% or more, and more preferably 85% or more. The upper limit of the light transmittance is 100% or less.

In the louver film 1, the resin materials forming the first transparent protective layer 13 and the second transparent protective layer 14 and the resin material forming the light transmitting band 11 may be the same or different from each other. The material of the first transparent protective layer 13 and the second transparent protective layer 14 is preferably polycarbonate resin, polyester resin, acrylic resin, polyolefin resin (particularly cycloolefin polymer), or cellulose resin from the viewpoint of transparency and heat resistance, and among them, polycarbonate resin and polyester resin are more preferable.

The first transparent protective layer 13 has a thickness in the Z direction that is too thin, and thus cannot provide a sufficient protective function, and the light transmittance decreases as the thickness increases, and therefore, the thickness is preferably about 0.01mm to 0.5mm, and more preferably about 0.1mm to 0.2 mm.

If the thickness of the second transparent protective layer 14 in the Z direction is too small, the workability is not good, and there is a problem in workability in manufacturing the louver film 1. Further, the light transmittance decreases as the thickness increases, and therefore, the thickness is preferably about 0.01mm to 0.5mm, more preferably about 0.1mm to 0.2 mm.

The first transparent protective layer 13 and the second transparent protective layer 14 are not essential members, but at least one of the first transparent protective layer 13 and the second transparent protective layer 14, preferably both of them, is provided from the viewpoint of protecting the louver layer 10, from the viewpoint of improving design performance, from the viewpoint of improving light transmittance, and the like.

The method of providing the first transparent protective layer 13 and the second transparent protective layer 14 on the front surface and the back surface of the louver layer 10 is not particularly limited, and a known method can be suitably used.

For example, an adhesive may be applied to the surface of the louver layer 10, and after a sheet made of the material of the first transparent protective layer 13 is attached, the adhesive may be cured. The second transparent protective layer 14 may be bonded to the back surface of the louver layer 10 in the same manner and integrated therewith.

The binder is preferably a binder having a high light transmittance after curing. Specifically, the light transmittance of the cured adhesive layer in the monomer is preferably 65% or more, more preferably 80% or more. The upper limit of the light transmittance is 100% or less. Examples of the binder include a thermosetting binder, a multi-liquid reaction binder, and an ultraviolet curing binder having transparency after curing. Specifically, for example, an epoxy resin adhesive, a polyurethane adhesive, an acryl adhesive, a melamine adhesive, a polyester adhesive, a silicone adhesive, or the like can be suitably used.

The thickness of the adhesive layer may be, for example, about 0.01 μm to 0.1 mm.

The louver film 1 can be obtained by the method described above.

< action Effect >

According to the louver film 1 of the present embodiment, for example, a light-transmitting window provided in a window of a building, a front windshield of an automobile, a head-up display, or the like can transmit only light having a specific incident angle within a light transmission angle θ range among light incident on the light-transmitting window. For example, as shown in fig. 3, when the forest 3, which is an object to be viewed outdoors, is viewed through the window glass of the building 2 to which the louver film 1 is attached, the direction of the vector connecting the observer a and the forest 3 in the room is the direction along the thickness direction (Z direction in fig. 2) of the light transmitting tape 11 and the light shielding tape 12 constituting the louver layer 10 of the louver film 1. That is, the vector of the light from the forest 3 toward the observer a is within the range of the light transmission angle θ of the louver film 1.

Therefore, the observer a can easily confirm the tree 3. In this case, since the pitch P of the louver layers is set to 300 μm or more, no ghost of the forest 3 is observed. On the other hand, since the angle of the vector connecting the pedestrian B outdoors and the observer a indoors is outside the range of the light transmission angle θ of the louver film 1, it is not easy to confirm the observer a from the pedestrian B. Similarly, since the angle of the vector connecting the sun S and the louver film 1 is out of the range of the light transmission angle θ of the louver film 1, the direct light from the sun S is less likely to enter the room.

< modification example one >

As a modification of the above embodiment, although not shown, an adhesive layer may be provided as the outermost layer on the opposite side of the first transparent protective layer 13. For example, the second transparent protective layer 14 may not be provided, and an adhesive layer may be provided on the entire rear surface of the louver layer 10. In addition, a structure in which an adhesive layer is laminated on the second transparent protective layer 14 can be exemplified.

The material of the adhesive layer is preferably a material having high transparency, and may be a material having a sufficiently releasable adhesive force to a window substrate such as window glass, or may be a material that is not releasably adhered. As the adhesive agent capable of forming such an adhesive layer, commercially available products can be applied, and examples thereof include an acrylic adhesive agent, a polyurethane adhesive agent, and a rubber adhesive agent. Specific examples of the rubber-based adhesive include silicone rubber, silicone gel, urethane rubber, and urethane gel. Among these, silicone rubber is preferable in that the amount of residual slurry after peeling is small and the transparency is high. The formed adhesive layer may be mirror finished.

According to the above modification, since the louver film can be bonded to the surface of the window base, the loss of transmitted light is less than that in a structure in which an air layer is present between the louver film and the window base.

< modification example two >

In the above embodiment, the orientation of the light-shielding tape 12 (the longitudinal direction of the long side of the light-shielding tape 12 in the cross section) in the cross section (Y-Z cross section) of fig. 2 is parallel to the thickness direction (Z direction) of the louver film 1, but the orientation of the light-shielding tape 12 may be inclined with respect to the Z direction. For example, as shown in fig. 4, the direction of the light-shielding tape 12 of the louver film 1 provided on the window glass on the second floor of the building 2 is inclined with respect to the Z direction (the thickness direction of the window glass) along the direction in which the observer a in the room looks down on the floor surface. According to this configuration, the observer a in the room can easily observe the visible object 3 on the floor, and the incidence of direct sunlight from the sun S located in the upward direction of the observer a can be suppressed.

Examples

[ example one ]

A louver film 1 having the structure shown in fig. 1 and 2 was produced.

First, a first thin plate having a thickness of 480 μm and made of transparent silicone rubber (trade name: KE153U, manufactured by shin-Etsu chemical industries, Ltd.) was prepared as the light-transmitting tape 1.

A second thin plate having a thickness of 20 μm and made of a black material prepared by adding carbon black to transparent silicone rubber (trade name: KE153U, manufactured by shin-Etsu chemical) was prepared as the light-shielding tape 12.

Next, a plurality of first thin plates and a plurality of second thin plates are alternately stacked, and then heated, vulcanized, and pressed to form a block in which the plurality of thin plates are integrated. The louver layer 10 was produced by slicing the block in a cut plane perpendicular to the surface of the sheet and at a thickness of 740 μm.

Then, a polycarbonate sheet (first and second transparent protective layers 13 and 14) having a thickness of 100 μm, which was coated with a thermosetting adhesive (trade name: KE1825, manufactured by shin-Etsu chemical industries, Ltd.) was stuck to both sides of the obtained louver layer 10, and heat-cured to produce the louver layer 10.

In the louver film 1 manufactured in this example, the pitch P of the light-shielding tapes 12 was 500 μm, the width of the light-shielding tapes 12 was 20 μm, and the thickness of the louver layer 10 was 740 μm.

With the louver film 1 of the present embodiment, the light transmittance is measured while varying the measurement angle, that is, the angle of the optical axis from the light source to the light receiver and the Z direction in the Y-Z plane in fig. 1 and 2. As a result, the louver film 1 of the present example had a light transmission angle θ of 100 ° and a light transmittance in the Z direction of 80%. The light transmittance of light incident from an angle exceeding the light transmittance angle θ is less than 5%.

The louver film 1 of the present embodiment is held in the hand and, in a state where the arm is extended, the direction of the line of sight is blocked and the following visible object is observed through the louver film 1.

As the visible objects, the outdoor building group, the outdoor sign, the fluorescent lamp on the ceiling, and the red line in the horizontal direction of the liquid crystal screen displayed on the PC were observed, and no ghost was observed, and the visual objects were confirmed well. In the observation, the transmittance of light exceeding the range of the light transmission angle θ was low, and it was confirmed that the function as a louver was sufficiently exhibited.

[ comparative example one ]

A louver film was produced in the same manner as in example 1, except that the thickness of the first sheet in example one was changed to 130 μm to form a louver layer. In the louver film of this comparative example, the pitch P of the light-shielding tape 12 was 150 μm, the width of the light-shielding tape was 20 μm, and the thickness of the louver layer was 200 μm. The light transmission angle θ of the louver film is about 100 °.

In the same observation experiment as in example one, using the louver film of the comparative example, no double or triple blurred ghost was observed with respect to any of the contour of the outdoor building group, the outdoor sign, the fluorescent lamp of the ceiling, and the red line in the horizontal direction of the liquid crystal screen displayed on the PC.

Industrial applicability

The utility model discloses a tripe formula membrane can wide application in the window of building, the front windshield of car or head-up display etc..

Description of the reference numerals

1 … louvered film; 10 … layers of louvre leaves; 11 … light transmitting tape; 12 … light-shielding tape.

Claims

1. A louver film comprises louver layers alternately arranged with light transmitting bands and light shielding bands,

the louvered film is characterized in that,

the pitch of the light-shielding tape is 300 μm or more and 1100 μm or less.

2. A louvered film as in claim 1,

an aperture ratio represented by { the width of the light-transmitting band/(the width of the light-transmitting band + the width of the light-shielding band) } × 100% is 90% or more and 99.9% or less.

3. A louvered film as in claim 1 or 2,

the thickness of the louver layer is more than 350 μm and less than 3000 μm.

4. A louvered film as in claim 1,

the pitch of the light-shielding tapes is 300 [ mu ] m or more and 500 [ mu ] m or less.

5. A louvered film as in claim 1,

the pitch of the light-shielding tapes is 350 [ mu ] m or more and 500 [ mu ] m or less.

6. A louvered film as in claim 1,

the light-shielding tapes are uniform in width and fixed in the longitudinal direction.

7. A louvered film as in claim 1,

the width of the light-shielding tape is 1-100 μm.

8. A louvered film as in claim 1 or 4 or 5,

the width of the light-transmitting band is 270 [ mu ] m or more.

9. A louvered film as in claim 1,

the ratio of the width of the light-shielding band/the width of the light-transmitting band is 0.005 or more and 0.5 or less.

10. A louvered film as in claim 1,

in a cross section of the louver layer in a thickness direction, an orientation of a side of the light-shielding tape along the thickness direction is parallel to the thickness direction of the louver layer.

11. A louvered film as in claim 1,

in a cross section of the louver layer in a thickness direction, an orientation of a side of the light-shielding tape in the thickness direction is inclined with respect to the thickness direction of the louver layer.

12. A louvered film as in claim 1,

at least one of the surface and the back of the louver layer is provided with a transparent protective layer.

13. A louvered film as in claim 1,

the planar shape of the louver film is a rectangle, the length of the rectangle is more than 1cm and less than 1000cm, and the width of the rectangle is more than 1cm and less than 1000 cm.