JP7286263B2 - sun visor - Google Patents

Description

The present disclosure relates to a light control device capable of adjusting visible light transmittance. Alternatively, the present disclosure relates to sun visors using such dimming devices.

2. Description of the Related Art Conventionally, a light control device having a light control sheet using a liquid crystal modulation element or the like is known. There are two types of light control sheets: the base material is a glass plate, and the base material is a resin film. The resin film is superior in mass productivity and impact resistance (difficult to crack), and has a lightweight and thin structure. can do. Such a light control sheet is described, for example, in Patent Document 1 filed by the present applicant.

Light control sheets have the advantage of being relatively easy to manufacture due to their excellent mass productivity, but their weaknesses are that they cannot maintain their shape due to their flexibility and are easily damaged by external forces. There is For this reason, the upper and lower surfaces of the light control sheet 515 are protected by protective members 511 and 512, as disclosed in Patent Document 2, for example. FIG. 8 is FIG. 3B of Patent Document 2 and shows an example of a conventional light control device 510 . As the protective members 511 and 512, a glass plate or a resin plate (a thin plate made of acrylic, polycarbonate, or the like) is used.

However, in the layer structure shown in FIG. 8, the side end surfaces of the light control sheet 515, the adhesive layers 513 and 514, and the protective members 511 and 512 are easily accessible from the outside. For this reason, for example, foreign matter is likely to enter and accumulate between the light control sheet 515 and the protective members 511 and 512 . Furthermore, when a shear stress or a compressive stress is applied between the upper and lower protective members 511 and 512, the light control sheet 515 is easily distorted, and the transmittance of the light control sheet 515 becomes uneven within the plane. In addition, the appearance is also inferior because different materials appear on the side end surfaces. In particular, when a liquid crystal material is used for the light control sheet, in-plane unevenness in transmittance is remarkably caused by a slight unevenness in thickness.

Furthermore, when the light control device as described above is used, for example, in a sun visor of an automobile, various functions (for example, antireflection function, antifouling function, etc.) are added to the protective member etc. from the viewpoint of safety and visibility. It is desired to give

Japanese Patent No. 5910788 JP 2014-182287 A

The present invention has been made in view of the above problems. That is, an object of the present invention is to protect the end surfaces of the light control sheet and the protective plate and mechanically fix the protective plate and the protective member, thereby preventing the light control sheet from being distorted due to external forces (shearing force and compressive force). To provide a light control device which makes it difficult to cause such a phenomenon and is excellent in appearance.

A further object of the present invention is to provide a light control device having various functions such as an antireflection function, thereby providing a light control device suitable for use in sun visors of automobiles and the like.

The present disclosure includes a first protective plate and a second protective plate arranged to face the first protective plate;
a light control sheet provided between the first protection plate and the second protection plate;
a protective member supported by the first protective plate and the second protective plate and arranged to face the side end surface of the light control sheet;
The light control sheet is a light control device characterized in that the visible light transmittance can be adjusted by electronic control.

In such a light control device, the protection plate has at least one function of an antireflection function, a hard coat function, an antifouling function, an ultraviolet ray reflection or absorption function, and an infrared ray reflection or absorption function. good

The protective member may have at least one function of an antireflection function, a hard coat function, an antifouling function, an ultraviolet ray reflection or absorption function, and an infrared ray reflection or absorption function.

Alternatively, the present disclosure includes a first protection plate and a second protection plate arranged opposite the first protection plate;
A light control sheet provided between the first protective plate and the second protective plate,
The protective member has at least one function of an antireflection function, a hard coat function, an antifouling function, an ultraviolet reflection or absorption function, and an infrared reflection or absorption function,
The light control sheet is a light control device characterized in that the visible light transmittance can be adjusted by voltage application.

In the light control device described above, the antireflection function may be realized by setting the reflectance between the surface of at least one of the first and second protective plates and the air interface to be 1% or less.

Alternatively, the hard coat function may be achieved by having a pencil hardness of B or higher according to JIS K5600-5-4.

Alternatively, the antifouling function may be achieved by having a pure water contact angle of 95° or more.

More preferably, the contact angle of pure water on the surface of at least one of the first and second protective plates, that is, the surface of the antifouling layer is 112° or more, more preferably 114° or more. The slipping angle of pure water on the surface of the antifouling layer is preferably 30° or less, more preferably 15° or less, and still more preferably less than 8°. The contact angle was measured according to JIS R3257.

If the contact angle of pure water is 95° or more, the antifouling layer has a low surface free energy, so that it is difficult to get fouled. Further, when the sliding angle is 30° or less, the sliding property of the surface of the antifouling layer is improved, making it difficult for dirt to adhere, and the adhered dirt can be easily wiped off.

The contact angle is measured using a contact angle measuring device (for example, contact angle meter "DM 500" manufactured by Kyowa Interface Science Co., Ltd.), and the contact angle for pure water and n-hexadecane is measured by the θ / 2 method. It is required by

In the member of the present invention, the contact angle of n-hexadecane on the antifouling layer surface is preferably 50° or more, more preferably 55° or more, and still more preferably 60° or more. Also, the sliding angle of n-hexadecane on the surface of the antifouling layer is preferably 15° or less, more preferably 10° or less, and still more preferably 6° or less.

Alternatively, the UV reflection or absorption function may be achieved by having a UV transmittance of 0.1% or less with a wavelength of 350 nm.

Alternatively, the infrared reflection or absorption function may be realized by setting the average transmittance of infrared rays having a wavelength of 800 nm or more and 2,000 nm or less to 40% or less , more preferably 30% or less .

Moreover, the protective member may have visible light absorption.

In the light control device described above, an air layer may be interposed between the first protective plate or the second protective plate and the light control sheet.

At this time, at least one of the side of the first protective plate or the second protective plate facing the air layer and the side of the light control sheet facing the air layer has a reflective A protective layer may be provided.

The light control sheet is bonded to the first protective plate and/or the second protective plate via an optical adhesive sheet,
The optical adhesive sheet may have a thickness of 100 μm or more and 1,000 μm or less.

Alternatively, the present disclosure provides a light control device as described above,
and a holding member that holds the light control device.

According to the present disclosure, by protecting the end faces of the light control sheet and the protective plate with the protective member and mechanically fixing the protective plate and the protective member, the light control sheet is free from distortion due to external forces (shearing force and compressive force). It is possible to provide a light control device that is less likely to occur and has excellent beauty.

Alternatively, according to the present disclosure, by having various functions such as an antireflection function, it is possible to provide a light control device suitable for use in a sun visor of an automobile or the like.

1 is a schematic perspective view showing an example of a vehicle equipped with a sun visor employing a light control device according to the present disclosure; FIG. 2 is a schematic front view showing the sun visor of FIG. 1; FIG. 2 is a schematic top view of the sun visor of FIG. 1; FIG. Figure 2C is a schematic exploded perspective view of the sun visor of Figures 2A and 2B; It is a figure for demonstrating the manufacturing process of the light control apparatus employ|adopted as the sun visor of FIG. 2A and FIG. 2B. It is a figure for demonstrating the manufacturing process of the light control apparatus employ|adopted as the sun visor of FIG. 2A and FIG. 2B. It is a figure for demonstrating the manufacturing process of the light control apparatus employ|adopted as the sun visor of FIG. 2A and FIG. 2B. Figure 3 is a partial schematic cross-sectional view showing a protective member employed in the sun visor of Figures 2A and 2B; FIG. 2C is a schematic cross-sectional view showing a modification of the protective member employed in the sun visor of FIGS. 2A and 2B; FIG. 2C is a schematic cross-sectional view showing another modification of the protective member employed in the sun visor of FIGS. 2A and 2B; FIG. 2B is a schematic cross-sectional view showing still another modification of the protective member employed in the sun visor of FIGS. 2A and 2B; FIG. 2C is a partial schematic cross-sectional view showing a modification of the light control device employed in the sun visor of FIGS. 2A and 2B; FIG. 7 is a partial schematic cross-sectional view showing another modification of the light control device of FIG. 6; It is a schematic sectional drawing which shows an example of the layer structure of the conventional light control apparatus.

An embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view showing an example of a vehicle 1 equipped with a sun visor 100 employing a light control device 10 according to the present disclosure.

As shown in FIG. 1, the light control device 10 according to this embodiment can be used as a sun visor 100, for example. The light control device 10 can adjust the transmittance of visible light, as will be described later. Therefore, when used as the sun visor 100, the visible light transmittance can be adjusted as desired according to the driver's preference, which is convenient. In this specification, a sun visor 100 employing a light control device 10 according to an embodiment of the present disclosure will be described below with reference to FIGS. 2 to 5. FIG.

FIG. 2 is a schematic diagram of a sun visor 100 according to one embodiment of the disclosure. 2A is a schematic plan view of the sun visor 100, and FIG. 2B is a schematic top view of the sun visor 100. FIG. 3 is a schematic exploded perspective view of the sun visor 100 of FIGS. 2A and 2B.

As shown in FIGS. 2A and 2B, the sun visor 100 includes a light control device 10 and a holding member 20 that holds the light control device 10 . As shown in FIG. 3, the light control device 10 of the present embodiment includes a film liquid crystal 15 as a light control sheet and a first optical adhesive sheet (OCA) on one side (upper side in FIG. 3) of the film liquid crystal 15 : Optical Clear Adhesive) 13, and a second protective plate 12 bonded to the other side (lower side in FIG. 3) of the liquid crystal film 15 with a second optical adhesive sheet 14. and have

As shown in FIG. 3, the film liquid crystal 15 has wiring 15c. The wiring 15c is connected to a control device (not shown) provided in the vehicle 1 and is used to provide the film liquid crystal 15 with drive power and control signals. As an example, when the holding member 20 is transparent, the wiring 15c may be made substantially invisible from the outside by forming the wiring 15c with a transparent conductor. In this case, the appearance of the sun visor 100 can be improved.

The first protective plate 11 and the second protective plate 12 are for maintaining the shape of the liquid crystal film 15 constant and protecting the liquid crystal film 15 from scratches and stains. The first protective plate 11 and the second protective plate 12 of the present embodiment are transparent plates made of polycarbonate resin and having a thickness of 3 mm. Considering the use as the sun visor 100 in the light control device 10 according to the present embodiment, the molecular weight of the polycarbonate resin is preferably 17,000 or more, preferably 20,000 or more. This is because even if the dimmer 10 is damaged, the broken fragments of the first and second protective plates 11 and 12 do not have sharp edges, which reduces the possibility of injuring the passenger. be.

The first and second optical adhesive sheets 13 and 14 of the present embodiment are optically transmissive, i.e., transparent, adhesive sheets having a thickness of 500 μm, and constitute the first and second protective plates 11 and 12. It has substantially the same refractive index as polycarbonate resin. As a result, reflection of light at each interface between the first and second protective plates 11 and 12 and the first and second optical adhesive sheets 13 and 14 is reduced. The first and second optical adhesive sheets 13 and 14 preferably have a thickness of 100 μm or more and 1,000 μm or less. If the thickness is less than 100 μm, air bubbles are likely to be trapped when the first and second optical adhesive sheets 13 and 14 are attached to the first and second protective plates 11 and 12. On the other hand, the thickness is 1,000 μm. This is because if the thickness is greater than 100 mm, it is disadvantageous in terms of mass productivity, price and strength.

Of course, it is also possible to employ glass plates as the first and second protection plates 11 and 12 . However, when such a light control device is used for the sun visor 100, it is necessary to provide a scattering prevention sheet on the surface to improve safety so as not to injure the passenger when it is damaged.

As shown in FIGS. 2A and 3, the light control device 10 according to this embodiment includes a liquid crystal film 15, first and second optical adhesive sheets 13 and 14, and first and second protective plates 11 and 12. It further has a protective member 16 arranged to face the side end surface of the laminate. In other words, for example, if the stack is rectangular, the side end surfaces corresponding to two long sides and one short side that are not covered by the holding member 20 described later are covered with the protective member 16 .

The protective member 16 protects the side end faces of the laminate and prevents dust and dirt from adhering between the first and second protective plates 11 and 12 and the liquid crystal film 15 from the side end faces. be. The protection member 16 of the present embodiment is, for example, a polycarbonate resin member having a U-shaped cross section in which a groove 16g is defined, as shown in FIG. In this embodiment, the protective member 16 is made of a polycarbonate resin having a molecular weight of 17,000 or more, preferably 20,000 or more, in consideration of passenger safety.

In the light control device 10 of the present embodiment, the side edges of the laminate are fitted in the concave grooves 16g of the protective member, and in this state, they are bonded and fixed to each other. In particular, the protective member 16 is adhesively fixed to the first and second protective plates 11 and 12 . With such a configuration, even if a shearing force acts between the first protective plate and the second protective plate, the protective member 16 prevents relative movement between the first protective plate 11 and the second protective plate 12, This prevents the film liquid crystal 15 from being distorted. Furthermore, even when a compressive force acts between the first protective plate 11 and the second protective plate 12, the compressive force is also dispersed in the protective member 16, so that the distortion occurring in the film liquid crystal 15 is effectively reduced. reduced. In addition, in FIG. 3 , in order to avoid complication of the drawing, the protective member 16 is shown only at a position corresponding to one short side of the rectangular light control device 10 .

The sun visor 100 according to this embodiment has a holding member 20 for holding the light control device 10 and connecting the light control device 10 to the ceiling of the vehicle. In the present embodiment, as shown in FIGS. 2A to 3, the holding member 20 holds the area including the short sides to which the protective member 16 is not attached. The holding member 20 of the present embodiment includes a first cover 21 that covers the short side region of the light control device 10 from above (upper side in FIG. 3) and a second cover 21 that covers the end region from below (lower side in FIG. 3). It has two covers 22 and a shaft 23 (see FIGS. 2A and 2B) fixed to the first cover. The first and second covers 21 and 22 are composed of rectangular flat plates 21p and 22p and walls 21w and 22w provided on three sides of the flat plates 21p and 22p. The walls 21w and 22w are arranged to face each other when the first and second covers 21 and 22 are attached to the light control device 10, and are surrounded by the flat plates 21p and 22p and the walls 21w and 22w. The short side areas of the light control device 10 are accommodated in the space.

A shaft 23 is for connecting the first and second covers 21 and 22 to the ceiling of the vehicle 1 . Specifically, the shaft 23 is fixed to a support portion (not shown) provided on the ceiling of the vehicle 1 . This support portion supports the shaft 23 so that the light control device 10 can rotate freely and remains stationary at an arbitrary rotation angle. In other words, the sun visor 100 is movable between a retracted position in which the upper surface faces the ceiling of the vehicle 1 and a use position in which the sun visor 100 is raised at a predetermined angle with respect to the ceiling. This movement is realized by pivoting around the support.

Next, a method for manufacturing the sun visor 100 will be described with reference to FIG.

FIG. 4 is a diagram for explaining the manufacturing process of the sun visor 100 of FIGS. 2A and 2B. First, as shown in FIG. 4A, the first optical adhesive sheet 13 is attached to one side of the first protective plate 11 . Similarly, a second optical adhesive sheet 14 is attached to one side of the second protective plate 12 .

Then, as shown in FIG. 4B , the liquid crystal film 15 is overlaid on the second optical adhesive sheet 14 , and the second protective plate 12 is attached to one surface of the liquid crystal film 15 .

After that, as shown in FIG. 4C, the first protective plate 11 is attached to the other surface of the liquid crystal film 15 . This bonding is realized by the first optical adhesive sheet 13 previously attached to the first protective plate 11 .

Each of the above steps is performed in a low pressure environment, preferably in a vacuum environment. As a result, it is possible to prevent air bubbles from entering the bonding interface, thereby providing the light control device 10 with excellent aesthetics.

As shown in FIG. 3, the light control device 10 manufactured as described above has the protective members 16 attached to the side end surfaces of the three sides excluding the short side regions held by the holding member 20 .

FIG. 5A is a partial schematic cross-sectional view showing the protective member 16 employed in the sun visor 100 of FIGS. 2A and 2B. A specific manner of attachment between the side end face and the protective member 16 is as shown in FIG. 5A. That is, the side edges of the laminated body of the liquid crystal film 15 and the first and second protective plates 11 and 12 sandwiching the film liquid crystal 15 with the first and second optical adhesive sheets 13 and 14 interposed therebetween are the recesses of the protective member 16 . It is fitted in the groove 16g and fixed by adhesion.

A holding member 20 is attached to the short-side region to which the protective member 16 is not attached. Specifically, the end region of the light control device 10 is arranged in the portion surrounded by the rectangular flat plate 22p and the wall 22w of the second cover 22, and in this state, the first cover 21 is attached to the second cover 22. They are connected to each other by appropriate connecting members such as bolts. Although not shown, a fixing mechanism is provided between the first and second covers 21 and 22 and the light control device 10 to maintain the mutual connection state. 10 is designed not to fall off.

Next, the action of the sun visor 100 according to this embodiment will be described.

The sun visor 100 is normally in a retracted position with its upper surface facing the ceiling of the vehicle 1 . When the driver uses the sun visor 100 , the sun visor 100 is grasped and pulled downward to move it to a use position at a predetermined angle with respect to the ceiling of the vehicle 1 . This movement is achieved by pivoting the sun visor 100 about its axis 23 . As a result, the sun shining through the windshield is appropriately blocked, enabling safe and comfortable driving. In particular, the sun visor 100 according to this embodiment can adjust the visible light transmittance as desired. For example, when the driver operates a switch provided on the instrument panel of the vehicle 1, a control signal is transmitted to the film liquid crystal 15 via the wiring 15c, and the visible light transmittance of the light control device 10 is adjusted. be.

As described above, when the sun visor 100 is moved from the storage position to the use position, the sun visor 100 is touched by the driver's hands and fingers, so that the side edges of the light control device 10 are particularly susceptible to dirt. However, since the sun visor 100 according to the present embodiment is provided with the protective member 16 on the side end face of the light control device 10, dirt enters between the first and second protective plates 11 and 12 and the liquid crystal film 15. there is nothing As a result, the aesthetic appearance of the sun visor 100 is maintained even after long-term use.

According to the sun visor 100 according to the present embodiment as described above, since the side end surfaces of the liquid crystal film 15 and the first and second protective plates 11 and 12 are protected by the protective member 16, the side end surfaces are free from dirt. It is possible to provide the light control device 10 and the sun visor 100 which are excellent in appearance. Furthermore, since the first protective plate 11 and the second protective plate 12 are fixed to each other by the protective member 16, the position of the second protective plate 12 with respect to the first protective plate 11 does not shift (relative movement). , the film liquid crystal 15 can be prevented from being distorted.

In the above embodiment, OCA is used to bond the liquid crystal film 15 and the first and second protective plates 11 and 12, but it is also possible to bond them by heat sealing, for example. In this case, the first and second protective plates 11 and 12 can be attached to both sides of the liquid crystal film 15 in one step (there is no need to attach one side at a time), thereby simplifying the manufacturing process. can.

At least one of the first and second protective plates 11 and 12 of the light control device 10 as described above has an antireflection function, a hard coat function, an antifouling function, an ultraviolet reflection or absorption function, and an infrared reflection ultraviolet reflection or absorption function. functions.

As an example, if a low-reflection layer or non-reflection layer is provided on the surfaces of the first and second protective plates 11 and 12, the reflection of visible light on the surfaces is reduced or suppressed, thereby improving the transmittance of visible light. be done. The low reflection layer or non-reflection layer herein means a layer having a reflectance of 1% or less between the surface of at least one of the first and second protective plates and the air interface. Of course, the low-reflection layer or the non-reflection layer is applied to the surface of the film liquid crystal 15 instead of the surfaces of the first and second protective plates 11 and 12, or in addition to the surfaces of the first and second protective plates 11 and 12. may be provided. In this case as well, reflection of visible light on the surface of the film liquid crystal 15 is reduced or suppressed, so that the transmittance of visible light is improved. In addition, in measuring the reflectance, the spectral waveform of the transmitted light was measured using an ultraviolet-visible spectrophotometer V-7100 manufactured by JASCO Corporation.

Alternatively, if the surfaces of the first and second protection plates 11 and 12 are provided with a low-reflection layer or non-reflection layer for ultraviolet rays, the ultraviolet rays that directly reach the driver can be reduced. Furthermore, if the surface of the first and second protective plates 11 and 12 is provided with a low-reflection layer or non-reflection layer of infrared rays, the direct heat of the sun is less likely to be felt by the driver, so that the driver can drive comfortably. can be done.

Alternatively, it is possible to effectively reduce the ultraviolet rays that directly reach the driver when using the sun visor 100 by mixing a substance having ultraviolet absorption into the polycarbonate resin that constitutes the first and second protective plates 11 and 12. can be done. In addition, it is possible to reduce the amount of ultraviolet rays reaching the adhesive layer and the liquid crystal film, thereby preventing deterioration of materials due to ultraviolet rays. Further, instead of or in addition to the ultraviolet absorbing substance, an infrared absorbing substance may be mixed with the polycarbonate resin forming the first and second protective plates 11 and 12. , when using the sun visor 100, it is possible to effectively reduce the infrared rays that directly reach the driver.

In order to effectively reduce the ultraviolet rays reaching the driver, the transmittance of the first and second protective plates 11 and 12 for ultraviolet rays with a wavelength of 350 nm should be 0.1% or less. In order to effectively reduce infrared rays reaching the driver, the average transmittance of infrared rays having a wavelength of 800 nm or more and 2,000 nm or less of the first and second protective plates 11 and 12 should be 40% or less, more preferably 30%. % or less. In addition, in measuring the average transmittance, the spectrum waveform of the transmitted light was measured in the same manner as the visible light.

Alternatively, if a scratch-resistant hard coat layer is provided on the surfaces of the first and second protective plates 11 and 12, the first and second protective plates 11 and 12 are less likely to be scratched, and a beautiful appearance can be maintained for a long period of time. can be maintained. The hard coat layer may have, for example, a pencil hardness of B or higher according to JIS K5600-5-4, and can be formed using a UV or EB curable resin.

Alternatively, it is also effective to impart an antifouling function to the outer surfaces of the first and second protection plates 11 and 12 . Specifically, as described above, the contact angle of pure water on the surfaces of the first and second protective plates 11 and 12 is 95° or more, preferably 112° or more, and more preferably 114° or more. By providing the , the surfaces of the first and second protective plates 11 and 12 are less likely to be stained. Moreover, even if dirt adheres, the dirt can be easily removed, and the appearance can be maintained for a long period of time.

Each of the above functions may be used alone, or may be used in combination.

Furthermore, each of the functions described above can also be employed for the protective member 16 .

Since the protective member 16 is a member that surrounds the side end surfaces of the light control device 10, for example, if a low-reflection layer or non-reflection layer is provided on the surface of the protection member 16, visible light can be emitted over the entire area of the light control device 10. reflection is reduced or suppressed. Further, if a reflective layer that reflects ultraviolet rays or infrared rays is provided on the surface of the protective member 16, the ultraviolet rays or infrared rays that directly reach the driver can be reduced over the entire area of the light control device 10. FIG.

Alternatively, if the polycarbonate resin constituting the protective member 16 is mixed with a substance that absorbs ultraviolet rays or infrared rays, the ultraviolet rays or infrared rays that directly reach the driver when using the sun visor 100 can be reduced over a wider range.

Alternatively, by providing a scratch-resistant hard coat layer or antifouling layer on the surface of the protective member 16, the appearance of the protective member 16 can be maintained for a long period of time. In particular, since the protective member 16 is surely touched by a driver's hand when using the sun visor 100, providing the protective member 16 with a hard coat layer or an antifouling layer is effective in maintaining the appearance.

The protection member 16 also has the following functions. That is, when bonding the first protective plate 11 and the second protective plate 12 to both surfaces of the film liquid crystal 15, the alignment of both may be shifted. In this case, the side end surfaces of the first protective plate 11 and the second protective plate 12 are misaligned, but such misalignment can be made inconspicuous by arranging the protective member 16 on the side end surfaces. . In this case, it is effective to select a material with low visible light transmittance (light shielding property) as the protective member 16 .

Furthermore, if the first protective plate 11 and the second protective plate 12 are simply pasted on both sides of the liquid crystal film 15, the first protective plate 11 and the second protective plate 12 may warp due to temperature, humidity, ultraviolet rays, and the like. This may occur, and the film liquid crystal 15 may be distorted. Since the protection member 16 has the function of connecting the first protection plate 11 and the second protection plate, such warping can be suppressed.

Furthermore, the protective member 16 may have visible light absorption. In this case, the protective member 16 absorbs stray light generated at the side end surfaces of the laminated body composed of the film liquid crystal 15 , the first and second optical adhesive sheets 13 and 14 , and the first and second protective plates 11 and 12 . This prevents the side end face from undesirably shining due to the stray light. Furthermore, since the side end face is covered with the protective member 16, the appearance of the sun visor 100 is improved, and the commercial value can be increased.

Next, modified examples of the protective member 16 will be described with reference to FIGS. 5B to 5D.

Figures 5B-5D are schematic cross-sectional views showing various modifications of the protective member 16 that can be employed in the sun visor 100 of Figures 2A and 2B. In the modification shown in FIG. 5B, instead of the protection member 16 having a U-shaped cross section, a flat protection member 216 having a rectangular cross section is employed. This protective member 216 is made of, for example, polycarbonate resin with a thickness of 3 mm. As shown in the figure, the protective member 216 is a laminate of the liquid crystal film 15, the first and second optical adhesive sheets 13 and 14, and the first and second protective plates 11 and 12, which is formed by an appropriate adhesive 17. It is adhesively fixed to the side end face. In addition, the width of the protective member 216 (the length in the vertical direction in FIG. 5B) is sized to be the same as the thickness of the laminate, and the surfaces of the first and second protective plates 11 and 12 and the protective member 216 Both ends in the width direction of the member 216 are smoothly continuous.

Alternatively, in the modification shown in FIG. 5C, a protection member 316 having a convex cross section is employed. In this case, as shown in the figure, the light control device 10 is arranged so that the first and second protection plates 11 and 12 extend outside the peripheries of the liquid crystal film 15 and the first and second optical adhesive sheets 13 and 14 . is configured to Then, in a state in which the protruding portion 316p of the protective member 316 is fitted in the portion surrounded by the first and second protective plates 11 and 12, the liquid crystal film 15 and the outer peripheries of the first and second optical adhesive sheets 13 and 14. , the protective member 316 is adhesively fixed to the first and second protective plates 11 and 12 . Also in this modification, the width of the protective member 316 (the length in the vertical direction in FIG. 5C) is the film liquid crystal 15, the first and second optical adhesive sheets 13 and 14, the first and second protective plates 11, 12, and the surface of the light control device 10 and both ends of the protective member 316 in the width direction are smoothly continuous.

Alternatively, in a modification shown in FIG. 5D, an O-ring-shaped protective member 416 is employed. Specifically, similarly to the light control device 10 shown in FIG. 5C, the first and second protective plates 11 and 12 extend outside the peripheries of the film liquid crystal 15 and the first and second optical adhesive sheets 13 and 14. configured to exit. A protective member 416 is fitted in a portion surrounded by the first and second protective plates 11 and 12 and the side end surfaces of the liquid crystal film 15 and the first and second optical adhesive sheets 13 and 14 . In this modified example, the protective member 416 is adhesively fixed to the first and second protective plates 11 and 12 .

In addition, each protective member 16, 216, 326, 416 may be attached so as to surround the four sides of the light control device 10. FIG. However, in this case, each protection member 16, 216, 326, 416 needs to be provided with an opening or a notch for passing the wiring 15c provided on the film liquid crystal 15 therethrough.

As a further modified example, it is also possible to employ a mode in which the protective member 416 is combined with the protective member 16 having a U-shaped cross section or the flat plate-shaped protective member 216 . In this case, since the periphery of the light control device 10 is double-sealed, it is possible to more reliably prevent dust and dirt from entering through the periphery due to repeated use of the sun visor 100 . Furthermore, since the first protective plate 11 and the second protective plate 12 are fixed more firmly, even if a shearing force acts between the first protective plate and the second protective plate, the protective member 16 remains the first protective plate. Relative movement between the protective plate 11 and the second protective plate 12 is more reliably prevented. Furthermore, even if a compressive force acts between the first protective plate 11 and the second protective plate 12, the compressive force is also distributed to the protective member 16, so the distortion occurring in the film liquid crystal 15 is effectively reduced. be done.

Further, in the light control device 10 according to this embodiment, the optical adhesive sheets 13 and 14 are provided on both sides of the film liquid crystal 15, but in other embodiments, only one side of the film liquid crystal 15 is provided with an optical adhesive sheet. A mode in which 14 is provided is also possible.

FIG. 6 shows, as a modification of the light control device 10 employed in the sun visor 100 of FIGS. 1 is a schematic cross-sectional view; FIG. In the light control device 10 shown in FIG. 6, an air layer exists between the film liquid crystal 15 and the first protective plate 11 instead of the optical adhesive sheet. Also, in this modification, an O-ring-shaped protective member 416 is adhesively fixed to the first protective plate 11 and the second protective plate 12 , so that the first protective plate 11 is attached to the second protective plate 12 . Fixed.

Such a light control device 10 does not require a step of bonding the first optical adhesive sheet 13 to one side of the first protective plate 11 and a step of bonding the first protective plate 11 to the liquid crystal film 15 during manufacturing. Therefore, the manufacturing process is simplified. Furthermore, the first protection plate 11 and the film liquid crystal 15 are not in contact with each other. Therefore, even if a compressive force acts in the thickness direction of the light control device 10 when the driver grips the sun visor 100, the compressive force is not transmitted to the film liquid crystal 15, and display unevenness occurs on the film liquid crystal 15. never occur.

Moreover, FIG. 7 is a partial schematic sectional view showing another modification of the light control device 10 of FIG. In the light control device 10 shown in FIG. 7, a low-reflection layer or non-reflection layer 18 is provided on the side of the first protective plate 11 facing the air layer and the side of the liquid crystal film 15 facing the air layer. . The presence of this low-reflection layer or non-reflection layer 18 reduces light reflection at the interface between the first protection plate 11 and the air layer and at the interface between the liquid crystal film 15 and the air layer. As a result, the visible light transmittance of the light control device 10 as a whole is improved. In other words, deterioration of visibility due to light reflection at the interface between the first protection plate 11 and the air layer and the interface between the film liquid crystal 15 and the air layer is avoided. Of course, the low-reflection layer or non-reflection layer 18 may be provided only on either the side of the first protective plate 11 facing the air layer or the side of the liquid crystal film 15 facing the air layer. .

Although the light control device 10 provided in the sun visor 100 described above may be supplied with electric power as driving force from the vehicle 1, a part of the sun visor 100 (for example, a part of the holding member 20) is provided with a solar battery. (not shown) may be provided, and the driving power may be supplied from this solar cell. Furthermore, the amount of irradiation light may be determined from the output of the solar cell, and the transmittance may be automatically controlled accordingly.

Also, the sun visor 100 employing the film liquid crystal 15 as the light control sheet has been described, but a light control sheet or the like that adjusts transmittance by heating based on electronic control may also be employed.

In the above description, the example in which the light control device 10 is employed in the sun visor 100 is used, but the application of the light control device 10 is not limited to the sun visor. Other examples of applications include side windows and sunroofs of automobiles, and windows of vehicles such as trains and aircraft.

1 vehicle 10 light control device 11 first protective plate 12 second protective plate 13 first optical adhesive sheet 14 second optical adhesive sheet 15 film liquid crystal 15c wiring 16 protective member 16g concave groove 17 adhesive 18 non-reflective layer 20 holding member 21 First cover 21p Flat plate 21w Wall 22 Second cover 22p Flat plate 22w Wall 23 Shaft 100 Sun visor 216 Protective member 316 Protective member 316p Projection 326 Protective member 416 Protective member

Claims (10)

A sun visor comprising a light control device and a holding member that holds the light control device,
The light control device
a first protective plate and a second protective plate arranged to face the first protective plate;
a light control sheet provided between the first protection plate and the second protection plate;
a first adhesive layer contacting both the first protective plate and the light control sheet to join the first protective plate and the light control sheet;
a second adhesive layer contacting both the second protective plate and the light control sheet to join the second protective plate and the light control sheet;
a protective member supported by the first protective plate and the second protective plate and arranged to face the side end surface of the light control sheet;
The protective member has visible light absorptivity,
The light control sheet can adjust the visible light transmittance by electronic control,
The protective member is positioned between portions of the first protective plate and the second protective plate that extend outward from the outer circumference of the light control sheet, and is attached to the first protective plate and the second protective plate. A sun visor that is joined to face the side end face of the light control sheet. At least one of the first protective plate and the second protective plate has at least one function of an antireflection function, a hard coat function, an antifouling function, an ultraviolet reflection or absorption function, and an infrared reflection or absorption function. 2. A sun visor according to claim 1, comprising: 3. The sun visor according to claim 2, wherein the anti-reflection function is realized when the reflectance between the surface of at least one of the first and second protection plates and the air interface is 1% or less. 3. The sun visor according to claim 2, wherein the hard coat function is achieved by having a pencil hardness of B or higher according to JIS K5600-5-4. 3. The sun visor according to claim 2, wherein the antifouling function is realized by a pure water contact angle of 95[deg.] or more. 3. The sun visor according to claim 2, wherein said UV reflection or absorption function is achieved by having a UV transmittance of 0.1% or less with a wavelength of 350 nm. 3. The sun visor according to claim 2, wherein said infrared ray reflecting or absorbing function is realized by having an average transmittance of 40% or less for infrared rays having a wavelength of 800 nm or more and 2,000 nm or less. The light control sheet is bonded to the first protective plate via an optical adhesive sheet that constitutes the first adhesive layer,
The light control sheet is bonded to the second protective plate via an optical adhesive sheet that constitutes the second adhesive layer,
The optical adhesive sheet constituting the first adhesive layer has a thickness of 100 μm or more and 1,000 μm or less,
The optical adhesive sheet constituting the second adhesive layer has a thickness of 100 μm or more and 1,000 μm or less,
A sun visor according to any one of the preceding claims, characterized in that: The holding member has a cover fixed to a part of the peripheral edge of the light control device, and a shaft fixed to the cover and connected to the automobile,
The side end surface of the light control sheet is entirely covered with either the holding member or the protective member.
A sun visor according to any one of the preceding claims, characterized in that: The light control device has wiring electrically connected to the light control sheet and extending from between the first protection plate and the second protection plate,
The wiring extends from the light control device into the cover,
10. Sun visor according to claim 9 , characterized in that:

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