JPWO2021045100A1 - Dimming member - Google Patents

Abstract

The dimming member 10 includes a first dimming unit 20 and a second dimming unit 40 laminated on the first dimming unit 20. The first dimming unit 20 can adjust the visible light transmittance by applying a voltage. The haze value of the second dimming unit 40 can be adjusted by applying a voltage. The first dimming unit 20 is a first liquid crystal unit arranged between the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 and the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22. It has 30 and a reflective polarizing plate 23 arranged between the first absorption type polarizing plate 21 and the first liquid crystal unit 30. By applying a voltage, the first liquid crystal unit 30 can switch between a state in which light is transmitted while maintaining the polarization direction and a state in which light is transmitted by changing the polarization direction.

Description

The present invention relates to a dimming member.

Conventionally, an optical member capable of switching between a translucent state, an opaque state, and a reflective state as shown in Japanese Patent Application Laid-Open No. 2010-211084 is known. In order to switch between the translucent state, the opaque state and the reflective state, the optical member shown in Japanese Patent Application Laid-Open No. 2010-211084 includes a unit that changes the light transmission state and a unit that changes the light diffusion state. ing. As these units, a method using a liquid crystal display can be considered. Such an optical member has a fast response to switching between a translucent state, an opaque state and a reflective state. Japanese Unexamined Patent Publication No. 2010-211084 indicates that such an optical member is provided on a display surface of a display device.

On the other hand, there is a demand for a dimming member capable of switching the light transmission state. By using the optical member shown in JP-A-2010-211084 as a dimming member, it is considered that a dimming member capable of switching between a translucent state, an opaque state and a reflective state can be obtained.

However, the dimming member is required to be able to switch to a transparent state rather than a translucent state. That is, when observing from one side of the dimming member, it is required that the transparent state, the opaque state, and the reflective state can be switched. However, in the optical member described in Japanese Patent Application Laid-Open No. 2010-211084, in the observation from one side that is supposed to be observed, it is possible to switch only to the translucent state, the opaque state and the reflective state. On the other hand, in the observation from the side that is not supposed to be observed, it is possible to switch only to the transparent state and the opaque state.

The present invention has been made in consideration of such a point, and an object of the present invention is to enable the dimming member to switch between a transparent state, an opaque state, and a reflective state.

The dimming member of the present invention
The first dimming unit whose visible light transmittance can be adjusted by applying a voltage,
A second dimming unit, which is laminated on the first dimming unit and whose haze value can be adjusted by applying a voltage, is provided.
The first dimming unit includes a first absorption type polarizing plate and a second absorption type polarizing plate, a first liquid crystal unit arranged between the first absorption type polarizing plate and the second absorption type polarizing plate, and the first liquid crystal unit. It has a 1-absorbing polarizing plate and a reflective polarizing plate arranged between the first liquid crystal units.
By applying a voltage, the first liquid crystal unit can switch between a state in which light is transmitted while maintaining the polarization direction and a state in which light is transmitted by changing the polarization direction.

In the dimming member of the present invention, the first dimming unit may be arranged so that the side on which the first absorption type polarizing plate is arranged faces the second dimming unit.

In the dimming member of the present invention, the first dimming unit may be arranged so that the side on which the second absorption type polarizing plate is arranged faces the second dimming unit.

In the dimming member of the present invention, the transmission axis of the first absorption type polarizing plate and the transmission axis of the second absorption type polarizing plate may be arranged in a cross Nicol.

In the dimming member of the present invention, the first dimming unit may be capable of having at least three visible light transmittances.

In the dimming member of the present invention
The maximum visible light transmittance of the first dimming unit is 20% or more.
The minimum visible light transmittance of the first dimming unit may be 2% or less.

In the dimming member of the present invention, the second dimming unit may be capable of taking at least three haze values.

In the dimming member of the present invention
The maximum haze value of the second dimming unit is 80% or more, and is
The minimum haze value of the second dimming unit may be 15% or less.

In the dimming member of the present invention, the difference between the maximum haze value and the minimum haze value of the second dimming unit may be 80% or more.

In the dimming member of the present invention
The first liquid crystal unit may be a TN system, a VA system, an IPS system or an FFS system.

In the dimming member of the present invention
The second dimming unit has a second liquid crystal layer containing liquid crystal molecules whose orientation changes when a voltage is applied.
The second liquid crystal layer may be a polymer dispersion type liquid crystal layer or a polymer network type liquid crystal layer.

In the dimming member of the present invention, the second dimming unit may have a reflectance of 10% or less in a state where the haze value is maximized.

In the dimming member of the present invention, the second dimming unit may have a colored transparent layer.

In the dimming member of the present invention
The second dimming unit includes a second liquid crystal layer containing liquid crystal molecules whose orientation changes with the application of a voltage, and a second electrode layer for applying a voltage to the second liquid crystal layer.
The second electrode layer may be colored.

In the dimming member of the present invention
The second dimming unit has a second liquid crystal layer containing liquid crystal molecules whose orientation changes when a voltage is applied.
The second liquid crystal layer may contain a dichroic dye.

In the dimming member of the present invention
The second dimming unit has a second liquid crystal layer containing liquid crystal molecules whose orientation changes when a voltage is applied.
The end portion of the second liquid crystal layer may be located outside the end portion of the first absorption type polarizing plate, the end portion of the second absorption type polarizing plate, and the end portion of the reflection type polarizing plate.

In the dimming member of the present invention
The first liquid crystal unit has a first liquid crystal layer containing liquid crystal molecules whose orientation changes when a voltage is applied.
The second dimming unit has a second liquid crystal layer containing liquid crystal molecules whose orientation changes when a voltage is applied.
The end portion of the second liquid crystal layer may be located inside the end portion of the first liquid crystal layer.

In the dimming member of the present invention
A transparent support that supports the first dimming unit and the second dimming unit, a first bonding layer that joins the first dimming unit and the second dimming unit, and the transparent support and the above. Further provided with a second bonding layer for bonding the second dimming unit,
The first dimming unit includes a first adhesive layer that adheres the reflective polarizing plate and the first liquid crystal unit, and a second adhesive layer that adheres the second absorption type polarizing plate and the first liquid crystal unit. And have more
At least one of the first bonding layer, the second bonding layer, the first adhesive layer, and the second adhesive layer may cover the end portion of the second dimming unit.

According to the present invention, the dimming member can switch between a transparent state, an opaque state, and a reflective state.

FIG. 1 is a perspective view schematically showing an automobile in which a sun visor provided with a dimming member according to the present invention is arranged. FIG. 2 is a cross-sectional view of an example of the dimming member. FIG. 3 is a diagram for explaining an example of the second liquid crystal unit of the second dimming unit, and is a diagram showing a state in which the liquid crystal molecules are not oriented. FIG. 4 is a diagram for explaining an example of the second liquid crystal unit of the second dimming unit, and is a diagram showing a state in which the liquid layer molecules are oriented. FIG. 5 is a diagram for explaining another example of the second liquid crystal unit of the second dimming unit, and is a diagram showing a state in which the liquid crystal molecules are not oriented. FIG. 6 is a diagram for explaining another example of the second liquid crystal unit of the second dimming unit, and is a diagram showing a state in which the liquid crystal molecules are oriented. FIG. 7 is a schematic cross-sectional view showing an example of the dimming member in the observed state. FIG. 8 is a diagram for explaining the operation of an example of the dimming member. FIG. 9 is a diagram for explaining the operation of an example of the dimming member. FIG. 10 is a diagram for explaining the operation of an example of the dimming member. FIG. 11 is a diagram for explaining the operation of an example of the dimming member. FIG. 12 is a schematic cross-sectional view showing another example of the dimming member in the observed state. FIG. 13 is a diagram for explaining the operation of another example of the dimming member. FIG. 14 is a diagram for explaining the operation of another example of the dimming member. FIG. 15 is a diagram for explaining the operation of another example of the dimming member. FIG. 16 is a diagram for explaining the operation of another example of the dimming member. FIG. 17 is a cross-sectional view showing a modified example of the dimming member. FIG. 18 is a cross-sectional view showing another modified example of the dimming member.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, the scale and the aspect ratio and the like are appropriately changed from the actual scale and dimensions and exaggerated for the convenience of illustration and comprehension.

FIG. 1 shows a sun visor provided with the dimming member 10 as an example to which the dimming member 10 of the present embodiment is applied. As shown in FIG. 1, in the automobile 1, a sun visor is arranged inside the automobile 1 at a position facing the windshield 5. The sun visor can reduce sunlight and the like incident on the windshield 5 and give a good view to the occupants of the automobile 1.

FIG. 2 shows a cross-sectional view of the dimming member 10 of the present embodiment. The dimming member 10 is a plate-shaped member. The dimming member 10 can switch between a transparent state, an opaque state, and a reflective state when observed from one side. The transparent and opaque states may be adjusted automatically, for example, based on the brightness detected by the sensor. The transparent state means a state in which the other side can be observed from one side through the dimming member 10. Further, the opaque state means a state in which the other side cannot be observed from one side through the dimming member 10. Therefore, the opaque state includes a state in which light is diffused and transmitted and a state in which light is blocked. Further, the reflection state means a state in which when the dimming member 10 is observed from one side, the other side is observed. As shown in FIG. 2, the dimming member 10 includes a first dimming unit 20, a second dimming unit 40, a first transparent support 11, a second transparent support 12, and a first bonding layer 17. , And a second bonding layer 18. The second dimming unit 40 is laminated on the first dimming unit 20. The first transparent support 11 and the second transparent support 12 support the first dimming unit 20 and the second dimming unit 40. The first bonding layer 17 joins the first dimming unit 20 and the second dimming unit 40. The second bonding layer 18 joins the first transparent support 11 and the second dimming unit 40. In the example shown in FIG. 2, the first dimming unit 20 and the second dimming unit 40 are arranged between the first transparent support 11 and the second transparent support 12. More specifically, the first dimming unit 20 is arranged closer to the second transparent support 12 than the second dimming unit 40. That is, in the example shown in FIG. 2, each component of the dimming member 10 includes a first transparent support 11, a second bonding layer 18, a second dimming unit 40, a first bonding layer 17, and a first. The dimming unit 20 and the second transparent support 12 are laminated in this order in the stacking direction dL.

The first transparent support 11 and the second transparent support 12 support the first dimming unit 20 and the second dimming unit 40. The first transparent support 11 and the second transparent support 12 are plate-shaped members. The first transparent support 11 and the second transparent support 12 preferably contain at least one of acrylic and polycarbonate, and more preferably contain acrylic. For example, the first transparent support 11 and the second transparent support 12 may have a structure in which polycarbonate is laminated between two acrylics. Further, the molecular weight of the acrylic or polycarbonate contained in the first transparent support 11 and the second transparent support 12 is preferably 17,000 or more, and more preferably 20,000 or more. If the first transparent support 11 and the second transparent support 12 are made of such a material, even if the first transparent support 11 and the second transparent support 12 are damaged, the first transparent support 11 And the edge of the fragment of the second transparent support 12 is not sharpened. Therefore, the risk of injuring the user of the dimming member 10 can be reduced. However, the present invention is not limited to this, and the first transparent support 11 and the second transparent support 12 may be formed of a glass film. When the first transparent support 11 and the second transparent support 12 are made of a glass film, the user of the dimming member 10 is injured when the first transparent support 11 and the second transparent support 12 are damaged. It is preferable to provide a shatterproof sheet on the surface in order to reduce the risk of causing the film.

The first transparent support 11 and the second transparent support 12 have a thickness of 0.05 mm or more and 10 mm or less, preferably 0.5 mm or more and 3 mm or less. With such a thickness, the first transparent support 11 and the second transparent support 12 having excellent strength and optical characteristics can be obtained. Further, the first dimming unit 20 and the second dimming unit 40 arranged between the first transparent support 11 and the second transparent support 12 are deteriorated by ultraviolet rays from the outside. In order to suppress such deterioration of the first dimming unit 20 and the second dimming unit 40, it is preferable that the first transparent support 11 and the second transparent support 12 contain an ultraviolet absorber. The first transparent support 11 and the second transparent support 12 may be made of the same material and may be the same, or may be different from each other in at least one of the materials and the composition. For example, as shown in FIG. 2, in order to reduce the weight of the dimming member 10 while appropriately supporting the first dimming unit 20 and the second dimming unit 40, the first transparent support 11 is made thicker. The second transparent support 12 may be thinned.

In addition, "transparent" means having transparency to the extent that one side of the transparent support can be seen through the first transparent support 11 and the second transparent support 12. Means. Specifically, it means that the first transparent support 11 and the second transparent support 12 have a visible light transmittance of, for example, 30% or more, more preferably 70% or more. Visible light transmittance is the transmittance at each wavelength when measured within the measurement wavelength range of 380 nm to 780 nm using a spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation, JIS K 0115 compliant product). Is specified as the average value of.

The first bonding layer 17 joins the first dimming unit 20 and the second dimming unit 40. The second bonding layer 18 joins the first transparent support 11 and the second dimming unit 40. In the present embodiment, the first bonding layer 17 and the second bonding layer 18 are so-called OCA (Optically Clear Adhesive) or OCR (Optically Clear Resin). That is, the first bonding layer 17 and the second bonding layer 18 are transparent and have adhesiveness. The thickness of the first bonding layer 17 and the second bonding layer 18 is preferably 25 μm or more and 1000 μm or less. If the thickness is thinner than 25 μm, the distortion of the dimming member cannot be absorbed by the joint surface, so that bubbles and defects of the dimming member (for example, color unevenness due to defective liquid crystal GAP) are likely to occur. On the other hand, if the thickness is thicker than 1000 μm, it is disadvantageous in terms of mass productivity, price and strength.

Further, as shown in FIG. 2, it is preferable that the second bonding layer 18 extends in the stacking direction dL at its end and covers the end of the second dimming unit 40. Here, the end portion of each component means an end portion in a direction orthogonal to the stacking direction dL. In other words, it means the peripheral edge of each component in the plan view of the dimming member 10. In the example shown in FIG. 2, the second bonding layer 18 is in contact with the first bonding layer 17 by extending in the stacking direction dL. However, the second bonding layer 18 does not have to be in contact with the first bonding layer 17 as long as it covers the end portion of the second dimming unit 40. Alternatively, the first junction layer 17 and the second junction layer 18 may be integrally formed to cover the end portion of the second dimming unit 40. However, not limited to the illustrated example, the first bonding layer 17 and the second bonding layer 18 do not have to cover the end portion of the second dimming unit 40.

The first dimming unit 20 can adjust the visible light transmittance. By adjusting the visible light transmittance of the first dimming unit 20 to be high, the light incident on the first dimming unit 20 can be transmitted or reflected. Further, by adjusting the visible light transmittance of the first dimming unit 20 to be low, it is possible to block the light incident on the first dimming unit 20. Here, if the visible light transmittance is 10 cm square or less, a spectrophotometer (for example, "UV-3100PC" manufactured by Shimadzu Corporation, JIS K 0115 compliant product) is used, and the visible light transmittance is 10 cm square or more. If so, it is specified as the average value of the transmittance at each wavelength when measured within the measurement wavelength range of 380 nm to 780 nm using a color brightness meter (for example, “CS-150” manufactured by Konica Minolta).

As shown in FIG. 2, the first dimming unit 20 has a first absorption type polarizing plate 21, a second absorption type polarizing plate 22, a first liquid crystal unit 30, a reflection type polarizing plate 23, and a first adhesion. It has a layer 27 and a second adhesive layer 28. The first liquid crystal unit 30 is arranged between the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22. The reflective polarizing plate 23 is arranged between the first absorbing polarizing plate 21 and the first liquid crystal unit 30. The first adhesive layer 27 adheres the reflective polarizing plate 23 and the first liquid crystal unit 30. The second adhesive layer 28 adheres the second absorption type polarizing plate 22 and the first liquid crystal unit 30. Even if the first dimming unit 20 is arranged so that the side on which the first absorption type polarizing plate 21 is arranged faces the second dimming unit 40 as shown in FIG. 2 and FIG. 7 described later. good. Alternatively, the first dimming unit 20 may be arranged so that the side on which the second absorption type polarizing plate 22 is arranged faces the second dimming unit 40 as shown in FIG. 12 described later. .. The thickness of such a first dimming unit 20 is, for example, 0.1 mm or more and 3 mm or less.

The first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 decompose the incident light into two orthogonal polarizing components (p-polarizing component and s-polarizing component), and one direction (direction parallel to the transmission axis). ), And absorbs the linearly polarized light component (for example, s-polarized light component) that vibrates in the other direction (direction parallel to the absorption axis) orthogonal to one direction. Has the function of Further, the reflective polarizing plate 23 decomposes the incident light into two orthogonal polarization components (p-polarization component and s-polarization component) and vibrates in one direction (direction parallel to the transmission axis) (linearly polarization component). For example, a function of transmitting a p-polarized light component) and reflecting a linearly polarized light component (for example, an s-polarized light component) that vibrates in the other direction (direction parallel to the absorption axis) orthogonal to one direction, particularly a function of mirror reflection. have. The transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the second absorption type polarizing plate 22 may be arranged in parallel Nicol, but are preferably arranged in Cross Nicole. Further, the transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the reflection type polarizing plate 23 are arranged in parallel Nicol. Therefore, when the transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the second absorption type polarizing plate 22 are arranged on the cross Nicol, the transmission axis of the second absorption type polarizing plate 22 and the reflection type polarizing plate 23 The transmission axis of is arranged in the cross Nicol. Cross Nicol means that the angle formed by the transmission axes of the two polarizing plates is 85 ° or more, preferably 86 ° or more, more preferably 87 ° or more, and most preferably 90 °. The parallel Nicol means that the angle formed by the transmission axes of the two polarizing plates is 5 ° or less, preferably 4 ° or less, more preferably 3 ° or less, and most preferably 0 °.

The first adhesive layer 27 adheres the reflective polarizing plate 23 and the first liquid crystal unit 30, and the second adhesive layer 28 adheres the second absorption type polarizing plate 22 and the first liquid crystal unit 30. The first adhesive layer 27 and the second adhesive layer 28 are so-called OCA (Optically Clear Adhesive) or OCR (Optically Clear Resin). That is, the first adhesive layer 27 and the second adhesive layer 28 are transparent and have adhesiveness. The thickness of the first adhesive layer 27 and the second adhesive layer 28 is preferably 25 μm or more and 500 μm or less. If the thickness is thinner than 25 μm, the distortion of the dimming member cannot be absorbed by the joint surface, so that bubbles and defects of the dimming member (for example, color unevenness due to defective liquid crystal GAP) are likely to occur. On the other hand, if the thickness is thicker than 1000 μm, it is disadvantageous in terms of mass productivity, price and strength.

By applying a voltage, the first liquid crystal unit 30 can switch between a state in which light is transmitted while maintaining the direction of polarized light and a state in which light is transmitted by changing the direction of polarized light. The first liquid crystal unit 30 is used by being arranged between two polarizing plates 21 and 22, for example, a VA (Vertical Polarized) method, a TN (Twisted Nematic) method, an IPS (In Plane Switching) method, or an FFS (Fringe). Field Switching) method.

The first liquid crystal unit 30 has a pair of first transparent base materials 31, 32, a pair of first electrodes 33, 34, a first liquid crystal layer 35, and a sealing material 37. The pair of first electrodes 33, 34 are arranged between the pair of first transparent substrates 31, 32. The first liquid crystal layer 35 is arranged between the pair of first electrodes 33 and 34. The sealing material 37 seals the first liquid crystal layer 35 between the pair of first transparent base materials 31 and 32. Further, the first liquid crystal unit 30 includes an alignment film (not shown). The alignment film regulates the orientation of the liquid crystal molecules in the first liquid crystal layer 35.

The pair of first transparent base materials 31 and 32 are members that support each component of the first liquid crystal unit 30. As the material of the pair of first transparent substrates 31, 32, it is preferable to use a material having a high visible light transmittance. Specifically, when the first transparent base materials 31 and 32 are required to have high strength and reduction of liquid crystal unevenness, it is preferable to use glass as the first transparent base materials 31 and 32. On the other hand, when the first transparent base materials 31 and 32 are required to be lightweight and workable in shape, it is preferable to use a resin as the first transparent base materials 31 and 32. Examples of the resin used for the first transparent substrates 31 and 32 include an acetyl cellulose resin such as triacetyl cellulose (TAC), a polyester resin such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and polyethylene (PE). , Polypropylene (PP), Polystyrene, Polymethylpentene, EVA and other polyolefin resins, Polyvinyl chloride, Polyvinylidene chloride and other vinyl resins, Acrylic resins, Polyurethane resins, Polysulfone (PEF), Polyether sulfone ( Examples of resins such as PES), polycarbonate (PC), polysulfone, polyether (PE), polyether ketone (PEK), (meth) acronitrile, cycloolefin polymer (COP), cycloolefin copolymer, etc. can be exemplified, in particular. , Polycarbonate, cycloolefin polymer, polyethylene terephthalate and other resins are preferred. The visible light transmittance of the first transparent substrates 31 and 32 is preferably 90% or more. Further, the first transparent substrates 31 and 32 preferably have a thickness of 300 μm or more and 1200 μm or less in the case of glass, and have a thickness of 30 μm or more and 250 μm or less in the case of polyethylene terephthalate, for example. Is preferable. With such a thickness, the first transparent substrates 31 and 32 having excellent strength and optical characteristics can be obtained. The first transparent substrates 31 and 32 may be made of the same material and may be the same, or may be different from each other in at least one of the materials and the composition.

The first electrodes 33 and 34 are connected to a control device or the like and provide driving power and control signals to the first liquid crystal layer 35. The first electrodes 33 and 34 are preferably formed of a transparent conductor such as indium tin oxide (ITO). In this case, the first electrodes 33 and 34 are substantially invisible from the outside, and the appearance of the dimming member 10 can be improved. By applying a voltage to the first electrodes 33 and 34, the orientation of the liquid crystal molecules described later contained in the first liquid crystal layer 35 can be controlled.

The first liquid crystal layer 35 contains liquid crystal molecules. The orientation direction of the liquid crystal molecules contained in the first liquid crystal layer 35 is controlled by applying a voltage to an alignment film (not shown) or the first electrodes 33 and 34. That is, when a voltage is applied to the first electrodes 33 and 34, the orientation of the liquid crystal molecules changes. For example, the liquid crystal molecules contained in the first liquid crystal layer 35 are oriented in the direction according to the alignment film when no voltage is applied to the first liquid crystal layer 35, and the voltage is applied to the first electrodes 33 and 34. In this state, it is oriented in a direction that follows the direction of the electric field due to the applied voltage.

The sealing material 37 surrounds the first liquid crystal layer 35 in a circumferential shape. That is, the sealing material 37 partitions the first liquid crystal layer 35. Further, as shown in FIG. 2, the sealing material 37 is provided between the pair of transparent base materials 31 and 32. The sealing material 37 plays a role of preventing the liquid crystal molecules constituting the first liquid crystal layer 35 from leaking from between the pair of the first transparent base materials 31 and 32, and the pair of first transparent base materials 31, It adheres to 32 and plays a role of fixing both to each other. The sealing material 37 can be formed from, for example, a thermosetting resin such as an epoxy resin or an acrylic resin, an ultraviolet curable resin, or the like.

The first dimming unit 20 can change the orientation of the liquid crystal molecules of the first liquid crystal layer 35 in the first liquid crystal unit 30 by applying a voltage via the first electrodes 33 and 34. The polarization direction of the light transmitted through the first liquid crystal unit 30 can change depending on the orientation of the liquid crystal molecules. As an example, consider the case where the first liquid crystal unit 30 is of the TN method and the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 are arranged by cross Nicol. The TN type first liquid crystal unit 30 rotates the polarization direction of the transmitted light by 90 ° when no voltage is applied. Therefore, when light having a polarization component in a specific direction transmitted through the first absorption type polarizing plate 21 and the reflection type polarizing plate 23 passes through the first liquid crystal unit 30, the polarization direction of the first liquid crystal unit 30 is rotated by 90 °. .. As a result, light can pass through the second absorption type polarizing plate 22. On the other hand, the first liquid crystal unit 30 does not rotate the polarization direction of the transmitted light when a voltage is applied. Therefore, when light having a polarization component in a specific direction transmitted through the first absorption type polarizing plate 21 and the reflection type polarizing plate 23 passes through the first liquid crystal unit 30, the first liquid crystal unit 30 does not rotate the polarization direction. .. Therefore, light cannot pass through the second absorption type polarizing plate 22. In this way, by changing the orientation of the liquid crystal molecules of the first liquid crystal layer 35 in the first liquid crystal unit 30 by applying a voltage, it is possible to control the transmission and shading of light in the first dimming unit 20. By applying such a voltage, the first dimming unit 20 can be adjusted to a state in which the visible light transmittance is high and a state in which the visible light transmittance is low.

The visible light transmittance of the first dimming unit 20 can be adjusted to be 20% or more at the maximum so that the area within 1 m can be sufficiently visually recognized even at night. Is preferable. Further, the visible light transmittance of the first dimming unit 20 can be adjusted to be 27.5% or more so that the area within 5 m can be sufficiently visually recognized even at night. Is more preferable. Further, in order to maintain good visibility through the dimming member 10 even at night, it is more preferable that the visible light transmittance of the first dimming unit 20 can be adjusted to be 30% or more. By sufficiently increasing the visible light transmittance of the first dimming unit 20, it is possible for the first dimming unit 20 to sufficiently transmit or reflect light. Further, in order to block the outside light by the dimming member 10 at night, it is preferable that the visible light transmittance of the first dimming unit 20 can be adjusted to be 2% or less at the minimum. Further, in order to block the outside light by the dimming member 10 in the evening, it is more preferable that the visible light transmittance of the first dimming unit 20 can be adjusted to 1% or less. Further, it is more preferable that the visible light transmittance of the first dimming unit 20 can be adjusted to 0.5% or less in order to sufficiently block the outside light by the dimming member 10 in the daytime. By sufficiently lowering the visible light transmittance of the first dimming unit 20, it is possible to sufficiently block the light in the first dimming unit 20.

The second dimming unit 40 can adjust the haze value. By adjusting the haze value of the second dimming unit 40 to a high value, the light incident on the second dimming unit 40 can be transmitted while being diffused. Further, by adjusting the haze value of the second dimming unit 40 to a low value, the light incident on the second dimming unit 40 can be transmitted with almost no diffusion. Here, the haze value is expressed by the ratio of the diffusion transmittance to the total light transmittance of the target object, and means the diffusion rate of the light transmitted through the target object. The total light transmittance is the ratio of the amount of light transmitted through the target object to the amount of light entering the target object. The diffuse transmittance is the ratio of the amount of light that passes through the target object in a direction other than the straight direction, that is, the amount of light that is diffused and transmitted to the light that enters the target object. The total light transmittance and the diffuse transmittance can be measured by a haze meter conforming to JIS K 7361 (for example, manufactured by Murakami Color Technology Laboratory, product number: HM-150).

As shown in FIG. 1, the second dimming unit 40 has a pair of second transparent base materials 41 and 42, second electrodes 43 and 44, and a second liquid crystal layer 50. The second electrodes 43 and 44 are arranged between the pair of second transparent substrates 41 and 42. The second liquid crystal layer 50 is arranged between the second electrodes 43 and 44. The thickness of such a second dimming unit 40 is, for example, 100 μm or more and 500 μm or less.

The pair of second transparent base materials 41 and 42 are members that support each component of the second dimming unit 40. As the material of the pair of second transparent substrates 41 and 42, it is preferable to use a material having flexibility and high visible light transmittance. Examples of such second transparent substrates 41 and 42 include acetyl cellulose-based resins such as triacetyl cellulose (TAC), polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and polyethylene (PE). Polypropylene (PP), polystyrene, polymethylpentene, EVA and other polyolefin resins, polyvinyl chloride, polyvinylidene chloride and other vinyl resins, acrylic resins, polyurethane resins, polysulphon (PEF), polyether sulfone (PES) ), Polycarbonate (PC), polysulfone, polyether (PE), polyether ketone (PEK), (meth) acronitrile, cycloolefin polymer (COP), cycloolefin copolymer and other resins. Resins such as polycarbonate, cycloolefin polymer, and polyethylene terephthalate are preferable. However, the pair of second transparent substrates 41 and 42 may be thin-film glass. The visible light transmittance of the second transparent substrates 41 and 42 is preferably 90% or more. At least one of the second transparent substrates 41 and 42 is not limited to colorless and transparent, and may be colored and transparent. Alternatively, a colored transparent layer (for example, a hard coat layer) (not shown) may be laminated on at least one of the second transparent substrates 41 and 42. Here, colored transparency means that the transmittance of light in a specific wavelength range is intentionally low, but the transmittance of visible light as a whole is high, specifically, that the wavelength is 380 nm to 780 nm. It means that the average transmittance is 50% or more, preferably 60% or more. Further, in the case of polyethylene terephthalate, for example, the second transparent substrates 41 and 42 preferably have a thickness of 30 μm or more and 250 μm or less. With such a thickness, the second transparent substrates 41 and 42 having excellent strength and optical characteristics can be obtained. The second transparent substrates 41 and 42 may be made of the same material and may be the same, or may be different from each other in at least one of the materials and the composition.

The second electrodes 43 and 44 are connected to a control device or the like and provide driving power and control signals to the second liquid crystal layer 50. The second electrodes 43 and 44 are colored transparent such as a transparent conductor such as indium tin oxide (ITO) or poly (3,4-ethylenedioxythiophene): poly (styrene sulfonic acid) (PEDOT: PSS). It is preferably formed of a suitable conductor. In this case, the second electrodes 43 and 44 are substantially invisible from the outside, and the appearance of the dimming member 10 can be improved. Further, particularly when the second electrodes 43 and 44 are formed by PEDOT: PSS, the second electrodes 43 and 44 are formed by applying the material forming the second electrodes 43 and 44 to the second transparent base materials 41 and 42. Can be formed. That is, the second electrodes 43 and 44 can be easily manufactured.

The second liquid crystal layer 50 contains liquid crystal molecules. The orientation direction of the liquid crystal molecules contained in the second liquid crystal layer 50 is controlled by applying a voltage to the second electrodes 43 and 44. That is, when a voltage is applied to the second liquid crystal layer 50, the orientation of the liquid crystal molecules changes. For example, when no voltage is applied to the second liquid crystal layer 50, the liquid crystal molecules contained in the second liquid crystal layer 50 are not oriented. On the other hand, when a voltage is applied to the second liquid crystal layer 50, the liquid crystal molecules contained in the second liquid crystal layer 50 are oriented in a direction following the direction of the electric field due to the applied voltage.

The second dimming unit 40 can change the orientation of the liquid crystal molecules of the second liquid crystal layer 50 by applying a voltage via the second electrodes 43 and 44. The degree of diffusion of light transmitted through the second liquid crystal layer 50 can change depending on the orientation of the liquid crystal molecules. Thereby, the haze value of the second dimming unit 40 can be adjusted by applying a voltage. The second liquid crystal layer 50 is, for example, a polymer dispersed liquid crystal layer (PDLC) having liquid crystal molecules 52 dispersed in the polymer 55 shown in FIGS. 3 and 4, or shown in FIGS. 5 and 6. It is a polymer network type liquid crystal layer (PNLC) having liquid crystal molecules 52 arranged in voids formed inside a polymer network 56 made of a resin formed in a three-dimensional network. In addition, the polymer dispersion type liquid crystal layer and the polymer network type liquid crystal layer have a normal type in which the haze value is low when no voltage is applied and a reverse type in which the haze value is low when a voltage is applied. There is. The second liquid crystal layer 50 is not particularly limited, and either a normal type or a reverse type can be adopted.

The second liquid crystal layer 50 shown in FIGS. 3 and 4 is a normal type polymer-dispersed liquid crystal layer. The second liquid crystal layer 50 has a polymer 55 and a liquid crystal material 51. The polymer 55 is made of a cured resin product. The liquid crystal material 51 is arranged in the space formed in the polymer 55. The space in which the liquid crystal material 51 is housed is dispersed in the polymer 55. In this example, in the state where the voltage shown in FIG. 3 is not applied, the liquid crystal molecules 52 follow the wall surface of the polymer 55 forming the accommodation space of the liquid crystal material 51. That is, the liquid crystal molecules 52 are not oriented. The refractive index of the liquid crystal molecule 52 in the lateral direction is different from the refractive index of the liquid crystal material 51. Therefore, the light transmitted through the second liquid crystal layer 50 is refracted by the difference in refractive index between the liquid crystal material 51 and the liquid crystal molecules 52. Since the interface between the liquid crystal material 51 and the liquid crystal molecules 52 is irregularly formed, light is also refracted in an irregular direction. That is, the light transmitted through the second liquid crystal layer 50 is diffused. In this way, in a state where no voltage is applied, the second liquid crystal layer 50 is in a high haze state, and the transmitted light is diffused to make it opaque. On the other hand, in the state where the voltage shown in FIG. 4 is applied, the liquid crystal molecules 52 follow the direction of the electric field generated by the application of the voltage in the accommodation space of the liquid crystal material 51. That is, the liquid crystal molecules 52 are oriented. The refractive index of the liquid crystal molecule 52 in the longitudinal direction is the same as the refractive index of the liquid crystal material 51. Therefore, the light that passes through the second liquid crystal layer 50 passes through the second liquid crystal layer 50 without being refracted and therefore diffused. In this way, in the state where the voltage is applied, the second liquid crystal layer 50 is in a low haze state and becomes transparent. By applying such a voltage, the second dimming unit 40 can be adjusted to a state in which the haze value is high and a state in which the haze value is low.

The second liquid crystal layer 50 shown in FIGS. 5 and 6 is a normal type polymer network type liquid crystal layer. The second liquid crystal layer 50 has a polymer network 56 and a liquid crystal material 51. The polymer network 56 is made of a cured resin product. The liquid crystal material 51 is arranged in the space formed in the polymer network 56. In this example, in the state where the voltage shown in FIG. 5 is not applied, the liquid crystal molecules 52 follow the wall surface of the polymer network 56 forming the accommodation space of the liquid crystal material 51. That is, the liquid crystal molecules 52 are not oriented. The refractive index of the liquid crystal molecule 52 in the lateral direction is different from the refractive index of the liquid crystal material 51. Therefore, the light transmitted through the second liquid crystal layer 50 is refracted by the difference in refractive index between the liquid crystal material 51 and the liquid crystal molecules 52. Since the interface between the liquid crystal material 51 and the liquid crystal molecules 52 is irregularly formed, light is also refracted in an irregular direction. That is, the light transmitted through the second liquid crystal layer 50 is diffused. In this way, in a state where no voltage is applied, the second liquid crystal layer 50 is in a high haze state, and the transmitted light is diffused to make it opaque. On the other hand, in the state where the voltage shown in FIG. 6 is applied, the liquid crystal molecules 52 follow the direction of the electric field generated by the application of the voltage in the accommodation space of the liquid crystal material 51. That is, the liquid crystal molecules 52 are oriented. The refractive index of the liquid crystal molecule 52 in the longitudinal direction is the same as the refractive index of the liquid crystal material 51. Therefore, the light that passes through the second liquid crystal layer 50 passes through the second liquid crystal layer 50 without being refracted and therefore diffused. In this way, in the state where the voltage is applied, the second liquid crystal layer 50 is in a low haze state and becomes transparent. By applying such a voltage, the second dimming unit 40 can be adjusted to a state in which the haze value is high and a state in which the haze value is low.

In the normal type second liquid crystal layer 50, a positive type liquid crystal molecule 52 is used. On the other hand, in the reverse type second liquid crystal layer 50, a negative type liquid crystal molecule 52 is used, and a pair of alignment films capable of exerting an orientation regulating force with respect to the liquid crystal molecule 52 and maintaining vertical orientation are used for the second. The liquid crystal layer 50 is sandwiched.

In order to block the outside light by the dimming member 10 at night, the haze value of the second dimming unit 40 is preferably adjustable so as to be 80% or more at the maximum. Further, in order to block the outside light by the dimming member 10 in the evening, it is more preferable that the haze value of the second dimming unit 40 can be adjusted to be 85% or more. Further, it is more preferable that the haze value of the second dimming unit 40 can be adjusted to be 90% or more in order to sufficiently block the outside light by the dimming member 10 in the daytime. By sufficiently increasing the haze value of the second dimming unit 40, it is possible to diffuse the light and make the second dimming unit 40 opaque. Further, it is preferable that the haze value of the second dimming unit 40 can be adjusted to be 15% or less at the minimum so that the area within 1 m can be sufficiently visually recognized via the dimming member 10. .. Further, it is more preferable that the haze value of the second dimming unit 40 can be adjusted to be 10% or less so that the region within 5 m can be sufficiently visually recognized via the dimming member 10. Further, it is more preferable that the haze value of the second dimming unit 40 can be adjusted to 5% or less in order to maintain good visibility through the dimming member 10. By sufficiently lowering the haze value of the second dimming unit 40, it is possible to make the second dimming unit 40 sufficiently transparent.

Further, the difference between the maximum haze value and the minimum haze value of the second dimming unit 40 is preferably 80% or more, preferably 85% or more so that the haze value is clearly switched in the second dimming unit 40. Is more preferable.

Here, in the normal type second liquid crystal layer 50, the maximum haze value of the second dimming unit 40 is the haze value in the state where no voltage is applied to the second electrodes 43 and 44 (state of 0V). The minimum haze value refers to a haze value in a state where a voltage of 50 V is applied to the second electrodes 43 and 44 as a rectangular alternating current wave having a duty ratio of 50% and 110 Hz. On the other hand, in the reverse type second liquid crystal layer 50, the maximum haze value of the second dimming unit 40 is a voltage of 50 V, which is a rectangular alternating current wave having a duty ratio of 50% and 110 Hz on the second electrodes 43 and 44. The haze value in the applied state, and the minimum haze value means the haze value in the state where no voltage is applied to the second electrodes 43 and 44 (0V state).

The second dimming unit 40 preferably has a reflectance of 10% or less, and more preferably 8% or less in a state where the haze value is maximized. Here, the reflectance of the second dimming unit 40 is a reflectance (SCI) including specular reflection and diffuse reflection. The reflectance of the second dimming unit 40 can be measured by using, for example, a spectrocolorimeter / color difference meter (CM-700d manufactured by Konica Minolta).

The reflectance of the second dimming unit 40 can be reduced by coloring the second dimming unit 40 in a state where the haze value is maximized, preferably black. The second dimming unit 40 can be colored, for example, by having a colored transparent layer. The colored transparent layer may be at least one of the second transparent base materials 41 and 42, or may be a hard coat layer laminated on at least one of the second transparent base materials 41 and 42. Further, the second electrodes 43 and 44 may be colored and transparent.

Alternatively, the second liquid crystal layer 50 may contain a dichroic dye 53. In the examples shown in FIGS. 3 to 6, the dichroic dye 53 is arranged in the voids formed in the polymer 55 or inside the polymer network 56, similarly to the liquid crystal molecules 52. Like the liquid crystal molecule 52, the dichroic dye 53 follows the wall surface of the polymer 55 and the wall surface of the polymer network 56 in a state where no voltage is applied. At this time, the second liquid crystal layer 50 is in a high haze state and further exhibits the color of the dichroic dye 53. The dichroic dye 53 can have various colors depending on the material thereof, but is preferably black. On the other hand, in the state where the voltage is applied, the dichroic dye 53 follows the direction of the electric field generated by the application of the voltage. At this time, the second liquid crystal layer 50 is in a low haze state and does not exhibit the color of the dichroic dye 53. That is, the second liquid crystal layer 50 becomes transparent.

When the second liquid crystal layer 50 does not contain the dichroic dye 53, the total light transmittance of the second dimming unit 40 is transmitted in a state where a voltage is applied to the second liquid crystal layer 50, that is, in a low haze state. The ratio is preferably 70% or more, and the total light transmittance of the second dimming unit 40 is 50% or more in a state where no voltage is applied to the second liquid crystal layer 50, that is, in a high haze state. It is preferable that When the second liquid crystal layer 50 contains the dichroic dye 53, the second liquid crystal layer 50 is in a state where a voltage is applied to the second liquid crystal layer 50, that is, in a state where the haze is low and the dichroic dye 53 does not exhibit color. The total light transmittance of the two dimming unit 40 is preferably 20% or more. Further, in a state where no voltage is applied to the second liquid crystal layer 50, that is, in a state of high haze and a state in which the dichroic dye 53 exhibits color, the total light transmittance of the second dimming unit 40 is 10% or more. It is preferable that

Here, as shown in FIG. 2, in the dimming member 10, the end portion of the second liquid crystal layer 50 is the end portion of the first absorption type polarizing plate 21, the end portion of the second absorption type polarizing plate 22, and the reflection type. It is located outside the end of the polarizing plate 23. In other words, the second liquid crystal layer 50 covers the entire first absorption type polarizing plate 21, the second absorption type polarizing plate 22, and the reflection type polarizing plate 23. Further, the end portion of the second liquid crystal layer 50 is located inside the end portion of the first liquid crystal layer 35. In other words, the second liquid crystal layer 50 does not overlap with the sealing material 37. Here, the outside means a side separated from the center of the dimming member 10 in a direction orthogonal to the stacking direction dL. Further, the inside means a side approaching the center of the dimming member 10 in a direction orthogonal to the stacking direction dL. The end portion of the first liquid crystal layer 35 is a contact surface with the sealing material 37. The end of the second liquid crystal layer 50 is a portion along the outer peripheral edge of the polymer 55 or the polymer network 56. However, the end portion of the second liquid crystal layer 50 is located excessively outside the end portion of the first absorption type polarizing plate 21, the end portion of the second absorption type polarizing plate 22, and the end portion of the reflection type polarizing plate 23. In this case, or when the end portion of the second liquid crystal layer 50 is located excessively inward from the end portion of the first liquid crystal layer 35, the non-functional region of the dimming member 10 becomes large. Therefore, the length at which the end of the second liquid crystal layer 50 is located outside the end of the first absorption-type polarizing plate 21, the end of the second absorption-type polarizing plate 22, and the end of the reflection-type polarizing plate 23. The length at which the end of the second liquid crystal layer 50 is located inside the end of the first liquid crystal layer 35 is preferably short. Specifically, the end portion of the second liquid crystal layer 50 is 0.4 mm or less from the end portion of the first absorption type polarizing plate 21, the end portion of the second absorption type polarizing plate 22, and the end portion of the reflection type polarizing plate 23. It is preferable that the end portion of the second liquid crystal layer 50 is located only 0.4 mm or less inside the end portion of the first liquid crystal layer 35. In FIG. 2, the position of the end portion of the second liquid crystal layer 50 is indicated by the dotted line A, and the end portion of the first absorption type polarizing plate 21, the end portion of the second absorption type polarizing plate 22, and the reflective polarized light. The end of the plate 23 is shown by the dotted line B, and the end of the first liquid crystal layer 35 is shown by the dotted line C.

Next, an example of the dimming member 10 and the operation of the other examples will be described with reference to FIGS. 7 to 16. FIG. 7 is a cross-sectional view of an example of the dimming member 10. FIG. 12 is a cross-sectional view of an example of the dimming member 10. In FIGS. 7 and 12, components that can act on the incident light in the dimming member 10 are taken out and shown schematically. In FIGS. 8 to 11 and 13 to 16, the one-way arrow indicates the traveling direction of the light, and the two-way arrow surrounded by a circle indicates the polarization state of the light. In an example of the action of the dimming member 10 described below, the first liquid crystal layer 35 of the first dimming unit 20 is of the TN method, and the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 are Arranged in cross Nicol. Further, the second liquid crystal layer 50 of the second dimming unit 40 is a normal type polymer dispersion type liquid crystal layer.

First, as shown in FIG. 7, the adjustment when the first dimming unit 20 is arranged so that the side on which the first absorption type polarizing plate 21 is arranged faces the second dimming unit 40. The operation of the optical member 10 will be described. As shown in FIG. 7, when the first dimming unit 20 is arranged so that the side on which the first absorption type polarizing plate 21 is arranged faces the second dimming unit 40, the dimming member 10 Is assumed to be observed from the side of the first dimming unit 20. For example, when such a dimming member 10 is used as a sun visor as shown in FIG. 1, a car in which the side of the first dimming unit 20 is arranged inside the vehicle and the side of the second dimming unit 40 faces the windshield 5. Placed on the outside.

First, a case where no voltage is applied to both the first liquid crystal layer 35 and the second liquid crystal layer 50 will be described with reference to FIG. The light L1 incident on the dimming member 10 from the side of the first dimming unit 20 is external light or the like and is unpolarized light. That is, it contains a polarization component in any direction. The light L1 incident on the second absorption type polarizing plate 22 of the first dimming unit 20 transmits only the linearly polarized light component vibrating in the other direction. After that, in the first liquid crystal layer 35, the light L1 is rotated by 90 ° in the polarization direction. As a result, the light L1 passes through the second absorption type polarizing plate 22, the reflection type polarizing plate 23 arranged on the cross Nicol, and the first absorption type polarizing plate 21 without being reflected or absorbed. The light L1 transmitted through the first dimming unit 20 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a high haze state. Therefore, the light L1 is transmitted through the second liquid crystal layer 50 while being diffused. In this way, the light L1 incident on the dimming member 10 from the side of the first dimming unit 20 is emitted in a diffused state from the side of the second dimming unit 40.

The light L2 incident on the dimming member 10 from the side of the second dimming unit 40 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a high haze state. Therefore, the light L2 is transmitted through the second liquid crystal layer 50 while being diffused. The light L2 transmitted through the second dimming unit 40 is incident on the first dimming unit 20. This light L2 is diffused unpolarized light. That is, it contains a polarization component in any direction. The light L2 incident on the first absorption type polarizing plate 21 is transmitted only by a linearly polarized light component that oscillates in one direction. Since the transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the reflection type polarizing plate 23 are arranged in parallel Nicol, the light L2 transmitted through the first absorption type polarizing plate 21 is directly transmitted to the reflection type polarizing plate 23. Is transparent. After that, in the first liquid crystal layer 35, the light L1 is rotated by 90 ° in the polarization direction. As a result, the light L2 passes through the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 arranged on the cross Nicol without being absorbed. In this way, the light L2 incident on the dimming member 10 from the side of the second dimming unit 40 is emitted in a diffused state from the side of the first dimming unit 20.

From the above, when the dimming member 10 is observed from the side of the first dimming unit 20 when no voltage is applied to both the first liquid crystal layer 35 and the second liquid crystal layer 50, the dimming member 10 is light. It is understood that the dimming member 10 is observed to be cloudy and opaque due to the diffusion of light even when the dimming member 10 is observed from the side of the second dimming unit 40. Will be done. When the reflectance of the second dimming unit 40 is 10% or less in the state where the haze value is maximized, the side of the first dimming unit 20 and the side of the second dimming unit 40 are dark. Observed.

Next, a case where a voltage is applied to the first liquid crystal layer 35 and no voltage is applied to the second liquid crystal layer 50 will be described with reference to FIG. The light L3 incident on the dimming member 10 from the side of the first dimming unit 20 is external light or the like and is unpolarized light. That is, it contains a polarization component in any direction. The light L3 incident on the second absorption type polarizing plate 22 of the first dimming unit 20 transmits only the linearly polarized light component vibrating in the other direction. After that, the light L3 is transmitted through the first liquid crystal layer 35 without being rotated in the polarization direction. Therefore, the light L3 is reflected by the second absorption type polarizing plate 22 and the reflection type polarizing plate 23 arranged on the cross Nicol. The light L3 reflected by the reflective polarizing plate 23 passes through the first liquid crystal layer 35 and the second absorption type polarizing plate 22 again, and is emitted from the side of the first dimming unit 20. In this way, the light L3 incident on the dimming member 10 from the side of the first dimming unit 20 is emitted from the side of the first dimming unit 20.

The light L4 incident on the dimming member 10 from the side of the second dimming unit 40 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a high haze state. Therefore, the light L4 is transmitted through the second liquid crystal layer 50 while being diffused. The light L4 transmitted through the second dimming unit 40 is diffused unpolarized light. That is, it contains a polarization component in any direction. A part of the light L4 is incident on the first dimming unit 20, and the other part of the light L4 is an interface between the second dimming unit 40 and the first dimming unit 20, for example, the first dimming unit 20. Reflection occurs at the interface between the optical unit 20 and the first bonding layer 17 and at the interface between the second dimming unit 40 and the first bonding layer 17. A part of the light L4 incident on the first absorption type polarizing plate 21 is transmitted only by a linearly polarized light component oscillating in one direction. Since the transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the reflection type polarizing plate 23 are arranged in parallel Nicol, a part of the light L4 transmitted through the first absorption type polarizing plate 21 is a reflection type as it is. It passes through the polarizing plate 23. After that, a part of the light L4 is transmitted through the first liquid crystal layer 35 without being rotated in the polarization direction. Therefore, a part of the light L4 is absorbed by the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 arranged on the cross Nicol. As described above, a part of the light L4 incident on the dimming member 10 from the side of the second dimming unit 40 is absorbed by the dimming member 10 and is not emitted. On the other hand, the other part of the light L4 reflected at the interface between the second dimming unit 40 and the first dimming unit 20 is again incident on the second dimming unit 40 and diffused. In this way, the other part of the light L4 incident on the dimming member 10 from the side of the second dimming unit 40 is emitted from the second dimming unit 40 in a diffused state.

From the above, when a voltage is applied to the first liquid crystal layer 35 and no voltage is applied to the second liquid crystal layer 50, when the dimming member 10 is observed from the side of the first dimming unit 20, it is adjusted. The light member 10 is observed as a reflecting surface that reflects light, and when the light control member 10 is observed from the side of the second light control unit 40, the light control member 10 is observed to be cloudy and opaque due to the diffusion of light. Understood. When the reflectance of the second dimming unit 40 is 10% or less in the state where the haze value is maximized, the side of the second dimming unit 40 is observed dark.

Next, a case where a voltage is not applied to the first liquid crystal layer 35 and a voltage is applied to the second liquid crystal layer 50 will be described with reference to FIG. The light L5 incident on the dimming member 10 from the side of the first dimming unit 20 is external light or the like and is unpolarized light. That is, it contains a polarization component in any direction. The light L5 incident on the second absorption type polarizing plate 22 of the first dimming unit 20 transmits only the linearly polarized light component vibrating in the other direction. After that, in the first liquid crystal layer 35, the light L5 is rotated by 90 ° in the polarization direction. As a result, the light L5 passes through the second absorption type polarizing plate 22, the reflection type polarizing plate 23 arranged on the cross Nicol, and the first absorption type polarizing plate 21 without being reflected or absorbed. The light L5 transmitted through the first dimming unit 20 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a low haze state. Therefore, the light L5 passes through the second liquid crystal layer 50 without being diffused. In this way, the light L5 incident on the dimming member 10 from the side of the first dimming unit 20 is emitted from the side of the second dimming unit 40.

The light L6 incident on the dimming member 10 from the side of the second dimming unit 40 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a low haze state. Therefore, the light L6 passes through the second liquid crystal layer 50 without being diffused. The light L6 transmitted through the second dimming unit 40 is incident on the first dimming unit 20. The light L6 transmitted through the second dimming unit 40 is unpolarized light such as external light. That is, it contains a polarization component in any direction. The light L6 incident on the first absorption type polarizing plate 21 is transmitted only by a linearly polarized light component that oscillates in one direction. Since the transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the reflection type polarizing plate 23 are arranged in parallel Nicol, the light L6 transmitted through the first absorption type polarizing plate 21 is directly transmitted to the reflection type polarizing plate 23. Is transparent. After that, in the first liquid crystal layer 35, the light L6 is rotated by 90 ° in the polarization direction. As a result, the light L6 passes through the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 arranged on the cross Nicol without being absorbed. In this way, the light L6 incident on the dimming member 10 from the side of the second dimming unit 40 is emitted from the side of the first dimming unit 20.

From the above, when a voltage is not applied to the first liquid crystal layer 35 and a voltage is applied to the second liquid crystal layer 50, the dimming member 10 is observed from the side of the first dimming unit 20. It is understood that the dimming member 10 is observed transparently, and even if the dimming member 10 is observed from the side of the second dimming unit 40, the dimming member 10 is observed transparently.

Finally, a case where a voltage is applied to both the first liquid crystal layer 35 and the second liquid crystal layer 50 will be described with reference to FIG. The light L7 incident on the dimming member 10 from the side of the first dimming unit 20 is external light or the like and is unpolarized light. That is, it contains a polarization component in any direction. The light L7 incident on the second absorption type polarizing plate 22 of the first dimming unit 20 transmits only the linearly polarized light component vibrating in the other direction. After that, the light L7 is transmitted through the first liquid crystal layer 35 without being rotated in the polarization direction. Therefore, the light L7 is reflected by the second absorption type polarizing plate 22 and the reflection type polarizing plate 23 arranged on the cross Nicol. The light L7 reflected by the reflective polarizing plate 23 passes through the first liquid crystal layer 35 and the second absorption type polarizing plate 22 again, and is emitted from the side of the first dimming unit 20. In this way, the light L7 incident on the dimming member 10 from the side of the first dimming unit 20 is emitted from the side of the first dimming unit 20.

The light L8 incident on the dimming member 10 from the side of the second dimming unit 40 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a low haze state. Therefore, the light L8 passes through the second liquid crystal layer 50 without being diffused. The light L8 transmitted through the second dimming unit 40 is incident on the first dimming unit 20. The light L8 transmitted through the second dimming unit 40 is unpolarized light such as external light. That is, it contains a polarization component in any direction. The light L8 incident on the first absorption type polarizing plate 21 transmits only the linearly polarized light component that vibrates in one direction. Since the transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the reflection type polarizing plate 23 are arranged in parallel Nicol, the light L8 transmitted through the first absorption type polarizing plate 21 is directly transmitted to the reflection type polarizing plate 23. Is transparent. After that, the light L8 is transmitted through the first liquid crystal layer 35 without being rotated in the polarization direction. Therefore, the light L8 is absorbed by the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 arranged on the cross Nicol. As described above, the light L8 incident on the dimming member 10 from the side of the first dimming unit 20 is absorbed by the dimming member 10 and is not emitted.

From the above, when a voltage is applied to both the first liquid crystal layer 35 and the second liquid crystal layer 50, when the dimming member 10 is observed from the side of the first dimming unit 20, the dimming member 10 is light. When the dimming member 10 is observed from the side of the second dimming unit 40, it is understood that the dimming member 10 is observed as being shaded in black.

As described above, by applying a voltage to the first dimming unit 20 and the second dimming unit 40, the state observed from the side of the first dimming unit 20 and the state observed from the side of the second dimming unit 40. The state can be controlled as shown in Table 1 below.

That is, in the dimming member 10, the transparent state, the opaque state, and the reflective state are observed from the side of the first dimming unit 20 depending on whether or not a voltage is applied to the first liquid crystal layer 35 and the second liquid crystal layer 50. It is understood that it is switchable. Further, in the observation from the side of the second dimming unit 40, it is understood that the transparent state and the opaque state are switched, but there is no reflection state and the reflection of light is suppressed.

Next, as shown in FIG. 12, the operation of the dimming member 10 when the side on which the second absorption type polarizing plate 22 is arranged is arranged so as to face the second dimming unit 40 will be described. do. As shown in FIG. 12, when the side where the second absorption type polarizing plate 22 is arranged is arranged so as to face the second dimming unit 40, the dimming member 10 is the second dimming unit. It is supposed to be observed from the side of 40. For example, when such a dimming member 10 is used as a sun visor as shown in FIG. 1, the side of the first dimming unit 20 is arranged on the outside of the vehicle facing the windshield 5, and the side of the second dimming unit 40 is the vehicle. Placed inside.

First, a case where no voltage is applied to both the first liquid crystal layer 35 and the second liquid crystal layer 50 will be described with reference to FIG. The light L9 incident on the dimming member 10 from the side of the first dimming unit 20 is external light or the like and is unpolarized light. That is, it contains a polarization component in any direction. The light L9 incident on the first absorption type polarizing plate 21 transmits only a linearly polarized light component that vibrates in one direction. Since the transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the reflection type polarizing plate 23 are arranged in parallel Nicol, the light L9 transmitted through the first absorption type polarizing plate 21 is directly transmitted to the reflection type polarizing plate 23. Is transparent. After that, in the first liquid crystal layer 35, the light L9 is rotated by 90 ° in the polarization direction. As a result, the light L9 passes through the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 arranged on the cross Nicol without being absorbed. The light L9 transmitted through the first dimming unit 20 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a high haze state. Therefore, the light L9 transmits through the second liquid crystal layer 50 while being diffused. In this way, the light L9 incident on the dimming member 10 from the side of the first dimming unit 20 is emitted in a diffused state from the side of the second dimming unit 40.

The light L10 incident on the dimming member 10 from the side of the second dimming unit 40 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a high haze state. Therefore, the light L10 is transmitted through the second liquid crystal layer 50 while being diffused. The light L10 transmitted through the second dimming unit 40 is incident on the first dimming unit 20. This light L10 is diffused unpolarized light. That is, it contains a polarization component in any direction. The light L10 incident on the second absorption type polarizing plate 22 of the first dimming unit 20 transmits only the linearly polarized light component vibrating in the other direction. After that, in the first liquid crystal layer 35, the light L10 is rotated by 90 ° in the polarization direction. As a result, the light L10 passes through the second absorption type polarizing plate 22, the reflection type polarizing plate 23 arranged on the cross Nicol, and the first absorption type polarizing plate 21 without being reflected or absorbed. In this way, the light L10 incident on the dimming member 10 from the side of the second dimming unit 40 is emitted in a diffused state from the side of the first dimming unit 20.

From the above, when the dimming member 10 is observed from the side of the first dimming unit 20 when no voltage is applied to both the first liquid crystal layer 35 and the second liquid crystal layer 50, the dimming member 10 is light. It is understood that the dimming member 10 is observed to be cloudy and opaque due to the diffusion of light even when the dimming member 10 is observed from the side of the second dimming unit 40. Will be done. When the reflectance of the second dimming unit 40 is 10% or less in the state where the haze value is maximized, the side of the first dimming unit 20 and the side of the second dimming unit 40 are dark. Observed.

Next, a case where a voltage is applied to the first liquid crystal layer 35 and no voltage is applied to the second liquid crystal layer 50 will be described with reference to FIG. The light L11 incident on the dimming member 10 from the side of the first dimming unit 20 is external light or the like and is unpolarized light. That is, it contains a polarization component in any direction. The light L11 incident on the first absorption type polarizing plate 21 transmits only a linearly polarized light component that vibrates in one direction. Since the transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the reflection type polarizing plate 23 are arranged in parallel Nicol, the light L11 transmitted through the first absorption type polarizing plate 21 is directly transmitted to the reflection type polarizing plate 23. Is transparent. After that, the light L11 is transmitted through the first liquid crystal layer 35 without being rotated in the polarization direction. Therefore, the light L11 is absorbed by the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 arranged on the cross Nicol. As described above, the light L11 incident on the dimming member 10 from the side of the first dimming unit 20 is absorbed by the dimming member 10 and is not emitted.

The light L12 incident on the dimming member 10 from the side of the second dimming unit 40 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a high haze state. Therefore, the light L12 transmits through the second liquid crystal layer 50 while being diffused. The light L12 transmitted through the second dimming unit 40 is incident on the first dimming unit 20. This light L12 is diffused unpolarized light. That is, it contains a polarization component in any direction. The light L12 incident on the second absorption type polarizing plate 22 of the first dimming unit 20 transmits only the linearly polarized light component vibrating in the other direction. After that, the light L12 is transmitted through the first liquid crystal layer 35 without being rotated in the polarization direction. Therefore, the light L12 is reflected by the second absorption type polarizing plate 22 and the reflection type polarizing plate 23 arranged on the cross Nicol. The light L12 reflected by the reflective polarizing plate 23 passes through the first liquid crystal layer 35 and the second absorption type polarizing plate 22 again, and is incident on the second dimming unit 40 from the first dimming unit 20. The light L12 is diffused and transmitted through the second liquid crystal layer 50 of the second dimming unit 40, and is emitted from the side of the second dimming unit 40. In this way, the light L12 incident on the dimming member 10 from the side of the second dimming unit 40 is emitted in a diffused state from the side of the second dimming unit 40.

From the above, when a voltage is applied to the first liquid crystal layer 35 and no voltage is applied to the second liquid crystal layer 50, when the dimming member 10 is observed from the side of the first dimming unit 20, the dimming member 10 is adjusted. It is understood that the light member 10 is observed to be shaded black, and when the light control member 10 is observed from the side of the second light control unit 40, the light control member 10 is observed to be cloudy and opaque due to the diffusion of light. .. When the reflectance of the second dimming unit 40 is 10% or less in the state where the haze value is maximized, the side of the second dimming unit 40 is observed dark.

Next, a case where a voltage is not applied to the first liquid crystal layer 35 and a voltage is applied to the second liquid crystal layer 50 will be described with reference to FIG. The light L13 incident on the dimming member 10 from the side of the first dimming unit 20 is external light or the like and is unpolarized light. That is, it contains a polarization component in any direction. The light L13 incident on the first absorption type polarizing plate 21 transmits only a linearly polarized light component that vibrates in one direction. Since the transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the reflection type polarizing plate 23 are arranged in parallel Nicol, the light L13 transmitted through the first absorption type polarizing plate 21 is directly transmitted to the reflection type polarizing plate 23. Is transparent. After that, in the first liquid crystal layer 35, the light L13 is rotated by 90 ° in the polarization direction. As a result, the light L13 passes through the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 arranged on the cross Nicol without being absorbed. The light L13 transmitted through the first dimming unit 20 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a low haze state. Therefore, the light L13 passes through the second liquid crystal layer 50 without being diffused. In this way, the light L13 incident on the dimming member 10 from the side of the first dimming unit 20 is emitted from the side of the second dimming unit 40.

The light L14 incident on the dimming member 10 from the side of the second dimming unit 40 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a low haze state. Therefore, the light L14 passes through the second liquid crystal layer 50 without being diffused. The light L14 transmitted through the second dimming unit 40 is incident on the first dimming unit 20. The light L14 transmitted through the second dimming unit 40 is unpolarized light such as external light. That is, it contains a polarization component in any direction. The light L14 incident on the second absorption type polarizing plate 22 of the first dimming unit 20 transmits only the linearly polarized light component vibrating in the other direction. After that, in the first liquid crystal layer 35, the light L14 is rotated by 90 ° in the polarization direction. As a result, the light L14 passes through the second absorption type polarizing plate 22, the reflection type polarizing plate 23 arranged on the cross Nicol, and the first absorption type polarizing plate 21 without being reflected or absorbed. In this way, the light L14 incident on the dimming member 10 from the side of the second dimming unit 40 is emitted from the side of the first dimming unit 20.

From the above, when a voltage is not applied to the first liquid crystal layer 35 and a voltage is applied to the second liquid crystal layer 50, the dimming member 10 is observed from the side of the first dimming unit 20. It is understood that the dimming member 10 is observed transparently, and even if the dimming member 10 is observed from the side of the second dimming unit 40, the dimming member 10 is observed transparently.

Finally, a case where a voltage is applied to both the first liquid crystal layer 35 and the second liquid crystal layer 50 will be described with reference to FIG. The light L15 incident on the dimming member 10 from the side of the first dimming unit 20 is external light or the like and is unpolarized light. That is, it contains a polarization component in any direction. The light L15 incident on the first absorption type polarizing plate 21 transmits only a linearly polarized light component that vibrates in one direction. Since the transmission axis of the first absorption type polarizing plate 21 and the transmission axis of the reflection type polarizing plate 23 are arranged in parallel Nicol, the light L15 transmitted through the first absorption type polarizing plate 21 is directly transmitted to the reflection type polarizing plate 23. Is transparent. After that, the light L15 is transmitted through the first liquid crystal layer 35 without being rotated in the polarization direction. Therefore, the light L15 is absorbed by the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 arranged on the cross Nicol. As described above, the light L15 incident on the dimming member 10 from the side of the first dimming unit 20 is absorbed by the dimming member 10 and is not emitted.

The light L16 incident on the dimming member 10 from the side of the second dimming unit 40 is incident on the second liquid crystal layer 50 of the second dimming unit 40. The second liquid crystal layer 50 is in a low haze state. Therefore, the light L16 passes through the second liquid crystal layer 50 without being diffused. The light L16 transmitted through the second dimming unit 40 is incident on the first dimming unit 20. The light L16 transmitted through the second dimming unit 40 is unpolarized light such as external light. That is, it contains a polarization component in any direction. The light L16 incident on the second absorption type polarizing plate 22 of the first dimming unit 20 transmits only the linearly polarized light component vibrating in the other direction. After that, the light L16 is transmitted through the first liquid crystal layer 35 without being rotated in the polarization direction. Therefore, the light L16 is reflected by the second absorption type polarizing plate 22 and the reflection type polarizing plate 23 arranged on the cross Nicol. The light L16 reflected by the reflective polarizing plate 23 passes through the first liquid crystal layer 35 and the second absorption type polarizing plate 22 again, and is incident on the second dimming unit 40 from the first dimming unit 20. The light L16 passes through the second liquid crystal layer 50 and is emitted from the side of the second dimming unit 40. In this way, the light L16 incident on the dimming member 10 from the side of the second dimming unit 40 is emitted from the side of the second dimming unit 40.

From the above, when a voltage is applied to both the first liquid crystal layer 35 and the second liquid crystal layer 50, when the dimming member 10 is observed from the side of the first dimming unit 20, the dimming member 10 is black. It is understood that when the dimming member 10 is observed from the side of the second dimming unit 40 while being shielded from light, the dimming member 10 is observed as a reflecting surface that reflects light.

As described above, by applying a voltage to the first dimming unit 20 and the second dimming unit 40, the state observed from the side of the first dimming unit 20 and the state observed from the side of the second dimming unit 40. The state can be controlled as shown in Table 2 below.

That is, in the dimming member 10, the transparent state, the opaque state, and the reflective state are observed from the side of the second dimming unit 40 depending on whether or not a voltage is applied to the first liquid crystal layer 35 and the second liquid crystal layer 50. It is understood that it is switchable. Further, in the observation from the side of the first dimming unit 20, it is understood that the transparent state and the opaque state are switched, but there is no reflection state and the reflection of light is suppressed.

In the above description of the operation, the first liquid crystal layer 35 of the first dimming unit 20 is of the TN method. However, for example, the first liquid crystal layer 35 of the first dimming unit 20 may be of the VA method. When the first liquid crystal layer 35 is of the VA method, the light transmitted through the first liquid crystal layer 35 rotates its polarization direction by 90 ° when a voltage is applied. Therefore, the state of the light transmitted through the first dimming unit 20 when the voltage is applied to the first liquid crystal layer 35 and when the voltage is not applied is opposite to the case where the liquid crystal of the first liquid crystal layer 35 is of the TN method.

Further, in the above description of the action, the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 are arranged by cross Nicols. However, the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 may be arranged by parallel Nicole. When the first absorption type polarizing plate 21 and the second absorption type polarizing plate 22 are arranged by parallel Nicols, when the polarization direction is rotated by 90 ° in the first liquid crystal layer 35, the first absorption type polarizing plate 21 and the second absorption type polarizing plate 21 and the second absorption type polarizing plate 22 are arranged. The light transmitted through one of the two-absorbing polarizing plates 22 is absorbed by the other. Therefore, the states of the light transmitted through the first dimming unit 20 depending on whether the polarization direction is rotated by 90 ° by applying a voltage to the first liquid crystal layer 35 are the first absorption type polarizing plate 21 and the first This is the opposite of the case where the two-absorbing polarizing plate 22 is arranged with a cross Nicol.

By the way, when a dimming member is used as a sun visor of an automobile or the like, especially on the side observed by the occupants of the automobile, it is in a transparent state in order to secure visibility through the sun visor and in an opaque state in order to block outside light. It is required to be in a reflective state in order to confirm the situation inside the vehicle. That is, the dimming member is required to be able to switch between a transparent state, an opaque state, and a reflective state. However, as described above, the optical member shown in Japanese Patent Application Laid-Open No. 2010-211084 can only be switched between a translucent state, an opaque state, and a reflective state, and is not expected to be observed. In observation, it is only possible to switch between the transparent state and the opaque state. That is, when the optical member of Japanese Patent Application Laid-Open No. 2010-211084 is applied to the sun visor as a dimming member, it can only be switched between the translucent state, the opaque state and the reflective state when observed from one side, or the transparent state. And can only be switched to the opaque state.

On the other hand, the dimming member 10 of the present embodiment has the second dimming member 10 in the observation from the side of the first dimming unit 20 in the example shown in FIG. 7 and in the example shown in FIG. 12, as described above for the explanation of the operation. When observing from the side of the dimming unit 40, it is possible to switch between a transparent state, an opaque state, and a reflective state. Further, in the observation from the side of the second dimming unit 40 in the example shown in FIG. 7 and in the observation from the side of the first dimming unit 20 in the example shown in FIG. 12, there is no reflection state and the reflection of light is suppressed. It is less likely to cause unintended reflections.

Further, as shown in FIGS. 2 and 7, when the first dimming unit 20 is arranged so that the side on which the first absorption type polarizing plate 21 is arranged faces the second dimming unit 40. The dimming member 10 can switch between a transparent state, an opaque state, and a reflective state without applying a voltage to both the first liquid crystal layer 35 and the second liquid crystal layer 50. Therefore, the dimming member 10 can be switched between a transparent state, an opaque state, and a reflective state with low power consumption.

Alternatively, as shown in FIG. 12, when the first dimming unit 20 is arranged so that the side on which the second absorption type polarizing plate 22 is arranged faces the second dimming unit 40, the dimming is performed. The first liquid crystal layer 35, which has a relatively large weight among the constituent elements of the member 10, can be arranged near the center of the dimming member 10. Therefore, the stability of the dimming member 10 can be improved.

When the transmission axis of the first absorption type polarizing plate 21 is arranged parallel to the transmission axis of the second absorption type polarizing plate 22, the transmission axis of the first absorption type polarizing plate 21 and the second absorption type polarizing plate If the transmission axis of 22 is slightly deviated from the arrangement of the parallel Nicol, the light transmitted through the first liquid crystal layer 35 will pass through the first dimming unit 20 even if the polarization direction is rotated by 90 °. Light is easily generated. This is because the rotation of the light transmitted through the first liquid crystal layer 35 in the polarization direction is not completely limited to 90 ° due to variations in the thickness of the first liquid crystal layer 35, but variations occur. It is believed that there is. That is, it becomes difficult for the first dimming unit 20 of the dimming member 10 to sufficiently block light. On the other hand, when the transmission axis of the first absorption type polarizing plate 21 is arranged on the transmission axis of the second absorption type polarizing plate 22 and the cross Nicol, the transmission axis of the first absorption type polarizing plate 21 and the second absorption type polarizing plate Even if the transmission axis of 22 deviates from the arrangement of the cross Nicol, it is difficult to generate light that passes through the first dimming unit 20. That is, when the transmission axis of the first absorption type polarizing plate 21 is arranged on the transmission axis of the second absorption type polarizing plate 22 and the cross Nicol, the dimming member 10 is arranged as compared with the case where it is arranged on the parallel Nicol. It is easy to sufficiently block light in the first dimming unit 20. Therefore, it is preferable that the transmission axis of the first absorption type polarizing plate 21 is arranged on the transmission axis of the second absorption type polarizing plate 22 and the cross Nicol.

Therefore, in order for the first dimming unit 20 to absorb more light, particularly when no voltage is applied to the first liquid crystal layer 35, the transmission axis of the first absorption type polarizing plate 21 is the second absorption type polarizing plate. The VA method is a drive method in which the liquid crystal molecules of the first liquid crystal layer 35 are arranged on the transmission shaft of 22 and the cross Nicol and do not rotate in the polarization direction in the first liquid crystal layer 35 in a state where no voltage is applied. preferable. In this case, the minimum visible light transmittance of the first dimming unit 20 can be set to 0.5% or less without applying a voltage to the first liquid crystal layer 35.

Further, the second dimming unit 40 has a reflectance of 10% or less in a state where the haze value is maximized. When such a second dimming unit 40 is observed, the second dimming unit 40 is observed dark. Therefore, it is suppressed that the second dimming unit 40 reflects the light from the outside and makes the dimming member 10 inconspicuous.

Further, the second liquid crystal layer 50 contains a dichroic dye 53. According to the dichroic dye 53, when the second dimming unit 40 is in a high haze state, the second dimming unit 40 can be colored in any color, for example, black. Since the second liquid crystal layer 50 contains the dichroic dye 53, the dimming member 10 can be made inconspicuous when the second dimming unit 40 is in a high haze state. Alternatively, when the second dimming unit 40 is in a high haze state, the appearance of the dimming member 10 can be harmonized with the surrounding environment.

In the portion where the first absorption type polarizing plate 21, the second absorption type polarizing plate 22 and the reflection type polarizing plate 23 overlap, for example, in the above-mentioned example, a voltage is applied to the first liquid crystal layer 35 of the first dimming unit 20. If so, it will not allow light to pass through and will turn black. When the end portion of the second liquid crystal layer 50 is located inside the end portion of the first absorption type polarizing plate 21, the end portion of the second absorption type polarizing plate 22, and the end portion of the reflection type polarizing plate 23, the first The absorption type polarizing plate 21, the second absorption type polarizing plate 22 and the reflection type polarizing plate 23 have a portion not covered by the second liquid crystal layer 50. For example, in the above example, when a voltage is applied to the first liquid crystal layer 35 but no voltage is applied to the second liquid crystal layer 50, the portion covered by the second liquid crystal layer 50 is observed to be cloudy. However, the portion not covered by the second liquid crystal layer 50 is observed in black. That is, in the dimming member 10, a cloudy portion and a black portion are observed in a mixed manner. In particular, when observing the dimming member 10, the black portion becomes conspicuous with respect to the cloudy portion, and the appearance of the dimming member 10 is impaired.

On the other hand, in the present embodiment, the end portion of the second liquid crystal layer 50 is outside the end portion of the first absorption type polarizing plate 21, the end portion of the second absorption type polarizing plate 22, and the end portion of the reflection type polarizing plate 23. Is located in. In other words, the second liquid crystal layer 50 covers the entire first absorption type polarizing plate 21, the second absorption type polarizing plate 22, and the reflection type polarizing plate 23. Therefore, for example, when a voltage is applied to the first liquid crystal layer 35 but no voltage is applied to the second liquid crystal layer 50 in the above-mentioned example, the black portion is not observed and the entire liquid crystal layer becomes cloudy. Observed. Therefore, the appearance of the dimming member 10 is not easily impaired.

When the end portion of the second liquid crystal layer 50 is located outside the end portion of the first liquid crystal layer 35, the second liquid crystal layer 50 overlaps with the sealing material 37. The encapsulant 37 can scatter the transmitted light. When the second liquid crystal layer 50 overlaps with the sealing material 37, for example, when no voltage is applied to the second liquid crystal layer 50 in the above example, the portion where the second liquid crystal layer 50 overlaps with the sealing material 37. Then, the light is scattered by the second liquid crystal layer 50 and the sealing material 37. Therefore, the portion where the second liquid crystal layer 50 overlaps with the sealing material 37 is observed to be particularly white and conspicuous, and the appearance of the dimming member 10 is impaired.

On the other hand, in the present embodiment, the end portion of the second liquid crystal layer 50 is located inside the end portion of the first liquid crystal layer 35. In other words, the second liquid crystal layer 50 does not overlap with the sealing material 37. Therefore, for example, when a voltage is not applied to the second liquid crystal layer 50 in the above-mentioned example, there is no portion where light is doubly scattered, and the entire liquid crystal layer 50 is uniformly clouded and observed. Since there is no conspicuously observed portion in white, the appearance of the dimming member 10 is not easily impaired.

Further, the second bonding layer 18 covers the end portion of the second dimming unit 40. By covering the end portion of the second dimming unit 40 with the second bonding layer 18, the end portions of the second transparent base materials 41 and 42 of the second dimming unit 40 and the end portion of the second liquid crystal layer 50 are seconded. 2 Can be covered by the junction layer 18. Therefore, it is possible to prevent the second transparent base materials 41 and 42 and the second liquid crystal layer 50 from peeling off from the ends of the second transparent base materials 41 and 42. In addition, it is possible to prevent moisture or the like from entering between the second transparent base materials 41 and 42 and the second liquid crystal layer 50. Therefore, deterioration of the second electrodes 43, 44 and the like arranged between the second transparent base materials 41 and 42 and the second liquid crystal layer 50 is suppressed. That is, deterioration of the performance of the dimming member 10 is suppressed.

As described above, the dimming member 10 of the present embodiment is laminated on the first dimming unit 20 and the first dimming unit 20 whose visible light transmission rate can be adjusted by applying a voltage, and by applying a voltage. A second dimming unit 40 whose haze value can be adjusted is provided, and the first dimming unit 20 includes a first absorption type polarizing plate 21 and a second absorption type polarizing plate 22, a first absorption type polarizing plate 21 and It has a first liquid crystal unit 30 arranged between the second absorption type polarizing plates 22, and a reflective polarizing plate 23 arranged between the first absorption type polarizing plate 21 and the first liquid crystal unit 30. By applying a voltage, the first liquid crystal unit 30 can switch between a state in which light is transmitted while maintaining the polarizing direction and a state in which light is transmitted by changing the polarizing direction. According to such a dimming member 10, it is possible to switch between a transparent state, an opaque state, and a reflective state when observing from the side of the second dimming unit 40.

Such a dimming member 10 is not limited to the sun visor as shown in FIG. 1, and can be applied to, for example, an opening or a transparent portion such as a window portion of a moving body such as a building or an automobile.

It is possible to make various changes to the above-described embodiment.

For example, the visible light transmittance of the first dimming unit 20 can be taken not only in a high state and a low state but also in an intermediate state by appropriately adjusting the voltage applied to the first dimming unit 20. May be adjustable. That is, the first dimming unit 20 may be capable of having at least three visible light transmittances. Taking a certain visible light transmittance means that the visible light transmittance can be maintained. By setting the visible light transmittance of the first dimming unit 20 to an intermediate state, a part of the light incident on the first dimming unit 20 is transmitted from the side of the first absorption type polarizing plate 21 and the other part is shielded from light. It is possible to partially transmit the light incident on the first dimming unit 20 from the side of the second absorption type polarizing plate 22 and reflect the other part. Therefore, in the observation from the side of the first dimming unit 20, the first dimming unit 20 can be semi-transmitted and semi-shielded, and in the observation from the side of the second dimming unit 40, the first dimming unit 20 can be translucent and semi-reflected. That is, the dimming member 10 can be in a translucent semi-reflective state.

Further, the haze value of the second dimming unit 40 is adjusted not only in a high state and a low state but also in an intermediate state by appropriately adjusting the voltage applied to the second dimming unit 40. It may be possible. That is, the second dimming unit 40 may be capable of taking at least three haze values. Taking one haze value means that the haze value can be maintained. By setting the haze value of the second dimming unit 40 to an intermediate state, it is possible to transmit a part of the light incident on the second dimming unit 40 and diffuse the other part. Therefore, the first dimming unit 20 can be semi-transmitted and semi-diffused in the observation from the side of the first dimming unit 20, and the first dimming unit can be observed from the side of the second dimming unit 40. 20 can be semi-transparent semi-diffused or semi-reflective semi-diffused. That is, the dimming member can be in a semi-transparent semi-opaque state or a semi-reflective semi-opaque state.

Further, in the example shown in FIG. 2, the second bonding layer 18 covers the end portion of the second dimming unit 40. However, instead of the second bonding layer 18, the first bonding layer 17 may cover the end of the second dimming unit 40 as shown in FIG. 17, and the first adhesive layer 27 may cover the end portion of the second dimming unit 40 as shown in FIG. May cover the end of the second dimming unit 40. Alternatively, the second adhesive layer 28 may cover the end portion of the second dimming unit 40, which is limited to the illustrated example. Further, a plurality of the first bonding layer 17, the second bonding layer 18, the first adhesive layer 27 and the second adhesive layer 28 may cover the end portion of the second dimming unit 40. That is, at least one of the first bonding layer 17, the second bonding layer 18, the first adhesive layer 27, and the second adhesive layer 28 may cover the end portion of the second dimming unit 40. Even in this case, it is possible to prevent the second transparent base materials 41, 42 and the second liquid crystal layer 50 from peeling from the ends of the second transparent base materials 41, 42, and the second transparent base material 41, It is possible to prevent moisture or the like from entering between the 42 and the second liquid crystal layer 50 from the outside. Therefore, deterioration of the second electrodes 43, 44 and the like arranged between the second transparent base materials 41 and 42 and the second liquid crystal layer 50 is suppressed. That is, deterioration of the performance of the dimming member 10 is suppressed.

10 Dimming member 11 1st transparent support 12 2nd transparent support 17 1st junction layer 18 2nd junction layer 20 1st dimming unit 21 1st absorption type polarizing plate 22 2nd absorption type polarizing plate 23 Reflective polarization Plate 27 1st adhesive layer 28 2nd adhesive layer 30 1st liquid crystal unit 31, 32 1st transparent base material 33, 34 1st electrode 35 1st liquid crystal layer 37 Encapsulant 40 2nd dimming unit 41, 42 2nd Transparent substrate 43, 44 Second electrode 50 Second liquid crystal layer 51 Liquid crystal material 52 Liquid crystal molecule 53 Dichroic dye 55 Polymer 56 Polymer network

Claims (18)

The first dimming unit whose visible light transmittance can be adjusted by applying a voltage,
A second dimming unit, which is laminated on the first dimming unit and whose haze value can be adjusted by applying a voltage, is provided.
The first dimming unit includes a first absorption type polarizing plate and a second absorption type polarizing plate, a first liquid crystal unit arranged between the first absorption type polarizing plate and the second absorption type polarizing plate, and the first liquid crystal unit. It has a 1-absorbing polarizing plate and a reflective polarizing plate arranged between the first liquid crystal units.
The first liquid crystal unit is a dimming member capable of switching between a state in which light is transmitted while maintaining the polarization direction and a state in which light is transmitted by changing the polarization direction by applying a voltage. The dimming member according to claim 1, wherein the first dimming unit is arranged so that the side on which the first absorption type polarizing plate is arranged faces the second dimming unit. The dimming member according to claim 1, wherein the first dimming unit is arranged so that the side on which the second absorption type polarizing plate is arranged faces the second dimming unit. The dimming member according to any one of claims 1 to 3, wherein the transmission axis of the first absorption type polarizing plate and the transmission axis of the second absorption type polarizing plate are arranged on a cross Nicol. The dimming member according to any one of claims 1 to 4, wherein the first dimming unit can have at least three visible light transmittances. The maximum visible light transmittance of the first dimming unit is 20% or more.
The dimming member according to any one of claims 1 to 5, wherein the minimum visible light transmittance of the first dimming unit is 2% or less. The dimming member according to any one of claims 1 to 6, wherein the second dimming unit can take at least three haze values. The maximum haze value of the second dimming unit is 80% or more, and is
The dimming member according to any one of claims 1 to 7, wherein the minimum haze value of the second dimming unit is 15% or less. The dimming member according to any one of claims 1 to 8, wherein the difference between the maximum haze value and the minimum haze value of the second dimming unit is 80% or more. The dimming member according to any one of claims 1 to 9, wherein the first liquid crystal unit is a TN system, a VA system, an IPS system, or an FFS system. The second dimming unit has a second liquid crystal layer containing liquid crystal molecules whose orientation changes when a voltage is applied.
The dimming member according to any one of claims 1 to 10, wherein the second liquid crystal layer is a polymer-dispersed liquid crystal layer or a polymer network-type liquid crystal layer. The dimming member according to any one of claims 1 to 11, wherein the second dimming unit has a reflectance of 10% or less in a state where the haze value is maximized. The dimming member according to claim 12, wherein the second dimming unit has a colored transparent layer. The second dimming unit includes a second liquid crystal layer containing liquid crystal molecules whose orientation changes with the application of a voltage, and a second electrode layer for applying a voltage to the second liquid crystal layer.
The dimming member according to claim 12 or 13, wherein the second electrode layer is colored. The second dimming unit has a second liquid crystal layer containing liquid crystal molecules whose orientation changes when a voltage is applied.
The dimming member according to any one of claims 1 to 14, wherein the second liquid crystal layer contains a dichroic dye. The second dimming unit has a second liquid crystal layer containing liquid crystal molecules whose orientation changes when a voltage is applied.
The end portion of the second liquid crystal layer is located outside the end portion of the first absorption type polarizing plate, the end portion of the second absorption type polarizing plate, and the end portion of the reflection type polarizing plate. The dimming member according to any one of 15 to 15. The first liquid crystal unit has a first liquid crystal layer containing liquid crystal molecules whose orientation changes when a voltage is applied.
The second dimming unit has a second liquid crystal layer containing liquid crystal molecules whose orientation changes when a voltage is applied.
The dimming member according to any one of claims 1 to 16, wherein the end portion of the second liquid crystal layer is located inside the end portion of the first liquid crystal layer. A transparent support that supports the first dimming unit and the second dimming unit, a first bonding layer that joins the first dimming unit and the second dimming unit, and the transparent support and the above. Further provided with a second bonding layer for bonding the second dimming unit,
The first dimming unit includes a first adhesive layer that adheres the reflective polarizing plate and the first liquid crystal unit, and a second adhesive layer that adheres the second absorption type polarizing plate and the first liquid crystal unit. And have more
Any one of claims 1 to 17, wherein at least one of the first bonding layer, the second bonding layer, the first adhesive layer, and the second adhesive layer covers the end portion of the second dimming unit. The dimming member described in the section.

Images