JP2020109441A - Dimming device and dimming sheet - Google Patents

Abstract

To provide a dimming sheet and a dimming device that have high design properties.SOLUTION: A dimming device comprises: a dimming sheet 10a that includes a dimming layer 11 containing liquid crystal molecules and a pair of transparent electrode layers 12A and 12B holding the dimming layer 11 therebetween; and a control unit that controls magnitude of a voltage applied between the transparent electrode layers 12A and 12B. The dimming sheet 10a includes a plurality of regions R1a and R2a that have such a configuration that a relation between the magnitude of the voltage and a polarization direction of the liquid crystal molecules is different between the regions. The control unit switches the magnitude of the voltage between magnitude making the polarization direction equal to each other in the regions R1a and R2a and magnitude making the polarization direction different from each other in the regions R1a and R2a.SELECTED DRAWING: Figure 6

Description

The present invention relates to a light control sheet having a variable light transmittance, and a light control device including the light control sheet.

The light control sheet includes a light control layer containing a liquid crystal composition and a pair of transparent electrode layers sandwiching the light control layer (see, for example, Patent Document 1). A light control device includes the light control sheet and a control unit that controls application of a drive voltage to the pair of transparent electrode layers. The light transmittance of the light control sheet is changed by changing the alignment state of the liquid crystal molecules according to the potential difference between the pair of transparent electrode layers. The light control sheet is attached to, for example, a building material such as a window glass or a glass wall, a window glass of an automobile, or the like, and functions as a partition member that partitions the two spaces.

JP, 2017-187775, A

For example, the function of the light control sheet also as a decoration of a space, such as a shoji screen to which shoji paper having a pattern such as a faint or shade is attached, can greatly expand the range of application as a partition member. However, the above-mentioned light control sheet shows only a state of being colorless and transparent over the entire area of the sheet, or a state of simply showing a plain cloudy color due to light scattering, depending on the magnitude of the driving voltage. Therefore, there is a strong demand for enhancing the decorativeness of the light control sheet, such as the decorative beauty.

An object of the present invention is to provide a light control sheet and a light control device having high designability.

A light control device for solving the above problems, a light control layer including liquid crystal molecules, and a light control sheet including a pair of transparent electrode layers sandwiching the light control layer, and the magnitude of the voltage applied between the transparent electrode layers. And a control unit for controlling. The light control sheet includes a plurality of regions configured such that the relationship between the voltage and the polarization direction of the liquid crystal molecules is different between the regions, and the controller controls the magnitude of the voltage and the polarization direction. The size is made equal between the regions, and the polarization direction is made different between the regions.

According to the above configuration, in a state where the polarization directions of the liquid crystal molecules are different between regions, a difference in light transmittance occurs between the regions, and a pattern resulting from such a difference in light transmittance is visually recognized on the light control sheet. As a result, a light control sheet having a pattern is realized, so that the design of the light control sheet is improved.

In the above configuration, the control unit controls the magnitude of the voltage so that the polarization direction is the same between the regions and the transparent mode in which the light control sheet is transparent, and the polarization direction is different between the regions. The mode of the light control sheet between the halftone mode in which the light control sheet exhibits a pattern caused by the difference in light transmittance and the opaque mode in which the polarization directions are equal between the regions and the light control sheet is opaque. May be changed.

According to the above configuration, it is possible to change the decoration of the space facing the light control sheet by changing the mode, and various decoration effects by the light control sheet can be obtained. Further, by changing the mode, it is possible to adjust the amount of light taken from one space divided by the light control sheet to the other space.

In the above structure, in the light control sheet, the relationship between the magnitude of the voltage and the polarization direction of the liquid crystal molecules may be different between the regions because the thickness of the light control layer is different between the regions.

In the above configuration, a pair of transparent support layers sandwiching the light control layer and the pair of transparent electrode layers are provided, and the thickness of the light control layer in the region where the light control layer is thickest is the thickness of the transparent support layer. May be 1/3 or more.

In the above configuration, in the light control sheet, in at least one of the pair of transparent electrode layers, the thickness of the transparent electrode layer is different between the regions, and thus the relationship between the magnitude of the voltage and the polarization direction of the liquid crystal molecules. May differ between the regions.

In the above configuration, the light control sheet includes a pair of alignment layers sandwiching the light control layer, the pair of transparent electrode layers sandwich the light control layer and the pair of alignment layers, of the pair of alignment layers. At least one of the regions may have a different relationship between the magnitude of the voltage and the polarization direction of the liquid crystal molecules due to the thickness of the alignment layer being different between the regions.

According to each of the above configurations, a light control sheet exhibiting a pattern due to a difference in light transmittance is preferably realized. Further, such a light control sheet can be formed by forming a multilayer body in which each layer is laminated in a flat state and then pressing the multilayer body with a mold according to a desired pattern. Therefore, the multi-layer body can be formed and stored as a member common to various patterns, and the multi-layer body for use can be shipped as a dimming sheet having no pattern. Therefore, even when the light control sheet having various patterns is manufactured, the inventory of the light control sheet can be compressed and the manufacturing cost can be reduced.

In the above structure, in the light control sheet, the relationship between the magnitude of the voltage and the polarization direction of the liquid crystal molecules may be different between the regions because the polymer density in the light control layer is different between the regions.

In the above configuration, the light control sheet includes a pair of alignment layers sandwiching the light control layer, the pair of transparent electrode layers sandwich the light control layer and the pair of alignment layers, of the pair of alignment layers. In at least one of the regions, the relationship between the magnitude of the voltage and the polarization direction of the liquid crystal molecules may be different between the regions because the cured state of the alignment layer is different between the regions.

According to the above configuration, a light control sheet that exhibits a pattern due to a difference in light transmittance is preferably realized.
A light control sheet for solving the above-mentioned problems includes a light control layer containing a polymer and liquid crystal molecules, and a pair of transparent electrode layers sandwiching the light control layer. At least one of the thickness of the light control layer, the thickness of the transparent electrode layer, and the density of the polymer is different between regions, so that the magnitude of the voltage applied between the transparent electrode layers and the polarization of the liquid crystal molecules can be increased. It has a plurality of regions having different relationships with directions.

The light control sheet for solving the above problems is a light control layer containing a polymer and liquid crystal molecules, a pair of alignment layers sandwiching the light control layer, and a pair of transparent electrodes sandwiching the light control layer and the pair of alignment layers. And layers. Since the thickness of the alignment layer and at least one of the cured states of the alignment layer are different between regions, a plurality of different relations between the magnitude of the voltage applied between the transparent electrode layers and the polarization direction of the liquid crystal molecules are obtained. Area.

According to each of the above configurations, in the state where a voltage is applied to the transparent electrode layer so that the polarization directions of the liquid crystal molecules are different between the regions, a difference in the light transmittance occurs between the regions, which is caused by the difference in the light transmittance. The formed pattern is visually recognized on the light control sheet. As a result, a light control sheet having a pattern is realized, so that the design of the light control sheet is improved.

According to the present invention, the design of the light control sheet can be enhanced.

The figure which shows the structure of the light control apparatus provided with the normal type light control sheet about one Embodiment of a light control apparatus centering on the cross-section of a light control sheet. The figure which shows the structure of the light control apparatus provided with the reverse type light control sheet about one Embodiment of a light control apparatus centering on the cross-section of a light control sheet. The figure which shows an example of the light control sheet of a transparent mode about the light control device of one Embodiment. The figure which shows an example of the light control sheet of a halftone mode about the light control device of one Embodiment. The figure which shows an example of the light control sheet of an opaque mode about the light control device of one Embodiment. The figure which shows the cross-section of the light control sheet|seat of 1st form about the light control apparatus of one Embodiment. The figure which shows the relationship between an applied voltage and haze when the thickness of a light control layer differs. The figure which shows the cross-section of the multilayer body for light control sheets used for manufacture of the light control sheet of 1st form. The figure which shows the cross-section of the light control sheet of 2nd form about the light control device of one Embodiment. The figure which shows the cross-section of the light control sheet of 3rd form about the light control device of one Embodiment. The figure which shows the cross-section of the light control sheet|seat of 4th form about the light control apparatus of one Embodiment. The figure which shows the cross-section of the light control sheet|seat of 5th Embodiment about the light control apparatus of one Embodiment. The figure which shows the modification of a light control sheet about the light control device of one Embodiment. The figure which shows the modification of a light control sheet about the light control device of one Embodiment.

An embodiment of a light control sheet and a light control device will be described with reference to the drawings.
[Basic structure of dimmer]
With reference to FIGS. 1 and 2, the basic structure of the light control device will be described centering on the structure of the light control sheet included in the light control device.

As shown in FIG. 1, the light control device includes a light control sheet 10 and a control unit 20 that controls application of a drive voltage to the light control sheet 10. The light control sheet 10 has either a normal type structure or a reverse type structure. FIG. 1 shows a cross-sectional structure of a normal type light control sheet 10N.

The normal type light control sheet 10N includes a light control layer 11, a first transparent electrode layer 12A and a second transparent electrode layer 12B which are a pair of transparent electrode layers, and a first transparent support layer 13A which is a pair of transparent support layers. And a second transparent support layer 13B. The first transparent electrode layer 12A and the second transparent electrode layer 12B sandwich the light control layer 11, and the first transparent support layer 13A and the second transparent support layer 13B include the light control layer 11 and the transparent electrode layers 12A and 12B. Sandwiched between. The first transparent support layer 13A supports the first transparent electrode layer 12A, and the second transparent support layer 13B supports the second transparent electrode layer 12B.

12 A of 1st transparent electrode layers are connected to the control part 20 through the wiring extended from 15 A of 1st terminal parts connected to the surface of 12 A of 1st transparent electrode layers. The 2nd transparent electrode layer 12B is connected to the control part 20 through the wiring extended from the 2nd terminal part 15B connected to the surface of the 2nd transparent electrode layer 12B. In the first terminal portion 15A, the first transparent electrode layer 12A is exposed from the light control layer 11, the second transparent electrode layer 12B, and the second transparent support layer 13B at the end of the light control sheet 10N. It is located in the area. In the second terminal portion 15B, the second transparent electrode layer 12B is exposed from the light control layer 11, the first transparent electrode layer 12A, and the first transparent support layer 13A at the end of the light control sheet 10N. It is located in the area. The terminal portions 15A and 15B form a part of the light control sheet 10N.

The control unit 20 generates a driving voltage that is an AC voltage and applies the driving voltage to the first transparent electrode layer 12A and the second transparent electrode layer 12B. The magnitude of the drive voltage is variable and controlled by the controller 20.

The light control layer 11 includes a polymer and liquid crystal molecules. The light control layer 11 is formed of, for example, a polymer network liquid crystal (PNLC), a polymer dispersed liquid crystal (PDLC), a capsule nematic liquid crystal (NCAP) or the like. Composed. For example, the polymer network type liquid crystal includes a polymer network having a three-dimensional network shape and holds liquid crystal molecules in the voids of the polymer network. The liquid crystal molecules included in the light control layer 11 have, for example, positive dielectric anisotropy, and the dielectric constant in the major axis direction of the liquid crystal molecules is larger than the dielectric constant in the minor axis direction of the liquid crystal molecules. The light control layer 11 may include a dye having a predetermined color, which does not hinder the movement of liquid crystal molecules. With such a configuration, the light control sheet 10 having a predetermined color is realized.

Each of the first transparent electrode layer 12A and the second transparent electrode layer 12B is a transparent layer having conductivity. Examples of the material forming the transparent electrode layers 12A and 12B include indium tin oxide (ITO), fluorine-doped tin oxide (FTO), tin oxide, zinc oxide, carbon nanotube (CNT), poly(3,4-ethylenediethylene). Examples thereof include polymers containing oxythiophene) (PEDOT) and multilayer films containing Ag alloy thin films.

Each of the first transparent support layer 13A and the second transparent support layer 13B is a transparent base material. As the transparent support layers 13A and 13B, for example, a glass substrate or a silicon substrate, or a high material made of polyethylene, polystyrene, polyethylene terephthalate, polyvinyl alcohol, polycarbonate, polyvinyl chloride, polyimide, polysulfone, cycloolefin polymer, triacetyl cellulose, or the like. Molecular films are used.

Each of the first terminal portion 15A and the second terminal portion 15B includes, for example, a conductive adhesive layer such as a metal tape, a conductive film, or a conductive paste, a wiring board such as an FPC, a lead wire, or the like.

FIG. 2 shows a cross-sectional structure of the reverse type light control sheet 10R. The reverse type light control sheet 10R includes, in addition to the light control layer 11, the transparent electrode layers 12A and 12B, the transparent support layers 13A and 13B, a first alignment layer 14A and a first alignment layer 14A which are a pair of alignment layers sandwiching the light control layer 11. The two alignment layers 14B are provided. The first alignment layer 14A is located between the light control layer 11 and the first transparent electrode layer 12A, and the second alignment layer 14B is located between the light control layer 11 and the second transparent electrode layer 12B. That is, the first transparent electrode layer 12A and the second transparent electrode layer 12B sandwich the light control layer 11 and the alignment layers 14A and 14B.

The alignment layers 14A and 14B are vertical alignment films. When the first transparent electrode layer 12A and the second transparent electrode layer 12B are equipotential, the alignment layers 14A and 14B are arranged along the alignment layers 14A and 14B so that the long axis direction of the liquid crystal molecules included in the light control layer 11 is aligned with the alignment layers 14A and 14B. The liquid crystal molecules are aligned so as to be along the normal direction of the surface that spreads. On the other hand, the alignment layers 14A and 14B can change the major axis direction of the liquid crystal molecules included in the light control layer 11 to a direction other than the normal direction when a potential difference is generated between the transparent electrode layers 12A and 12B. ..

Examples of the material forming the alignment layers 14A and 14B include polyamide, polyimide, polycarbonate, polystyrene, polysiloxane, polyester such as polyethylene terephthalate and polyethylene naphthalate, and polyacrylate such as polymethyl methacrylate.

[Method of manufacturing light control sheet]
A standard manufacturing method of the light control sheet 10 will be described. The case where the light control layer 11 is composed of a polymer network liquid crystal will be described below. First, a method of manufacturing the normal type light control sheet 10N will be described.

First, the first transparent electrode layer 12A is formed on the surface of the first transparent support layer 13A, and the second transparent electrode layer 12B is formed on the surface of the second transparent support layer 13B. The transparent electrode layers 12A and 12B are formed by a known thin film forming method such as sputtering, vacuum deposition, coating or the like depending on the material.

Then, the coating layer which is the precursor of the light control layer 11 is formed so as to be sandwiched between the first transparent electrode layer 12A and the second transparent electrode layer 12B. For forming the coating layer, for example, known coating methods such as an inkjet method, a gravure coating method, a spin coating method, a slit coating method, a bar coating method, a flexo coating method, a die coating method, a dip coating method, and a roll coating method. Used.

The coating liquid for forming the coating layer contains a monomer or oligomer of a polymer forming a polymer network in the light control layer 11, an ultraviolet ray reactive polymerization initiator, and a liquid crystal composition containing liquid crystal molecules. .. The coating liquid further secures various additives such as a defoaming agent and an antioxidant, and a space where the light control layer 11 is located between the first transparent electrode layer 12A and the second transparent electrode layer 12B. Particles serving as a support for forming may be included.

Then, the laminated body including the coating layer, the transparent electrode layers 12A and 12B, and the transparent support layers 13A and 13B is irradiated with ultraviolet rays. As a result, the monomers and oligomers contained in the coating layer are polymerized to form a polymer network, and the light control layer 11 in which liquid crystal molecules are held in the voids of the polymer network is formed.

The multilayer body for a light control sheet, which includes the light control layer 11, the transparent electrode layers 12A and 12B, and the transparent support layers 13A and 13B, is formed into a large-sized sheet by using a roll-to-roll method, for example. The light control sheet multilayer body is cut into a desired shape according to the application target of the light control sheet 10N, and the terminal portions 15A and 15B are formed on the cut out light control sheet multilayer body, thereby adjusting the light control sheet. The light sheet 10N is formed.

Next, a method of manufacturing the reverse type light control sheet 10R will be described. In the manufacturing process of the reverse type light control sheet 10R, the first alignment layer 14A is formed on the surface of the first transparent electrode layer 12A formed on the first transparent support layer 13A, and on the second transparent support layer 13B. The second alignment layer 14B is formed on the surface of the formed second transparent electrode layer 12B. For forming the alignment layers 14A and 14B, known methods such as an inkjet method, a gravure coating method, a spin coating method, a slit coating method, a bar coating method, a flexo coating method, a die coating method, a dip coating method, a roll coating method and the like are known. A coating method is used. The process for causing the alignment layers 14A and 14B to function as a vertical alignment film is, for example, a rubbing process, a polarized light irradiation process, or a fine processing process.

Then, the coating layer which is the precursor of the light control layer 11 is formed so as to be sandwiched between the first alignment layer 14A and the second alignment layer 14B. The method for forming the coating layer and the configuration of the coating liquid for forming the coating layer are the same as those for manufacturing the normal type light control sheet 10N. When the coating layer is sandwiched between the first alignment layer 14A and the second alignment layer 14B, the liquid crystal molecules contained in the coating layer are vertically aligned.

Then, the laminated body including the coating layer, the transparent electrode layers 12A and 12B, and the transparent support layers 13A and 13B is irradiated with ultraviolet rays. As a result, the monomers and oligomers contained in the coating layer are polymerized to form a polymer network, and the light control layer 11 in which liquid crystal molecules are held in the voids of the polymer network is formed.

The multilayer body for a light control sheet, which includes the light control layer 11, the transparent electrode layers 12A and 12B, the transparent support layers 13A and 13B, and the alignment layers 14A and 14B, is formed into a large-sized sheet by using a roll-to-roll method, for example. It is formed. The light control sheet multilayer body is cut out into a desired shape according to the application target of the light control sheet 10R, and the terminal portions 15A and 15B are formed on the cut out light control sheet multilayer body, whereby the light control sheet is formed. 10R is formed.

[Driving sheet drive mode]
The drive mode of the light control sheet 10 will be described with reference to FIGS. 3 to 5. The light control device has three drive modes for the light control sheet 10, which are a transparent mode, an opaque mode, and a halftone mode. The feature of the light control device of the present embodiment is that it has a halftone mode, and the light control sheet 10 of the present embodiment realizes a halftone mode in addition to the basic structure and manufacturing method described above. It has a feature to make it. This feature will be described later.

In the normal type, when the driving voltage is not applied to the transparent electrode layers 12A and 12B, that is, when the first transparent electrode layer 12A and the second transparent electrode layer 12B have the same potential, the light control layer 11 includes The orientation of the liquid crystal molecules in the long axis direction is irregular. Therefore, the light incident on the light control layer 11 is scattered and the light control sheet 10 becomes opaque. On the other hand, when a drive voltage is applied to the transparent electrode layers 12A and 12B and a potential difference is generated between the first transparent electrode layer 12A and the second transparent electrode layer 12B, liquid crystal molecules are aligned according to the potential difference, The major axis direction is along the electric field direction between the transparent electrode layers 12A and 12B. As a result, light is easily transmitted through the light control layer 11. The transparency of the light control sheet 10 increases as the applied drive voltage increases within a predetermined range.

In the reverse type, when the drive voltage is not applied to the transparent electrode layers 12A and 12B, the liquid crystal molecules are aligned by the alignment layers 14A and 14B, and the long axis direction of the liquid crystal molecules is in the normal direction of the alignment layers 14A and 14B. It will be along the direction. As a result, the light control sheet 10 becomes transparent. On the other hand, when a drive voltage is applied to the transparent electrode layers 12A and 12B, the liquid crystal molecules are different from the normal direction depending on the potential difference between the first transparent electrode layer 12A and the second transparent electrode layer 12B. It becomes difficult for light to pass through the light control layer 11 because The transparency of the light control sheet 10 decreases as the applied drive voltage increases within a predetermined range.

The transparent mode is a mode in which the light control sheet 10 is uniformly transparent. In the transparent mode, the light transmittance of the light control sheet 10, that is, the parallel light transmittance is near the maximum value, and the haze of the light control sheet 10 is near the minimum value. That is, in the transparent mode, a high-voltage drive voltage is applied in the normal type, and a low-voltage drive voltage is applied or the drive voltage is not applied in the reverse type. It is in a state.

The opaque mode is a mode in which the light control sheet 10 is uniformly opaque. In the opaque mode, the light transmittance of the light control sheet 10 is near the minimum value, and the haze of the light control sheet 10 is near the highest value. That is, the opaque mode is a state in which a low drive voltage is applied or a drive voltage is not applied in the normal type, and a high drive voltage is applied in the reverse type. It is in a state.

The halftone mode is a mode in which the light control sheet 10 includes a plurality of regions having light transmittances different from each other and exhibits a pattern resulting from the difference in light transmittance between these regions. In the halftone mode, the light transmittance of the light control sheet 10 has a magnitude between the light transmittance in the transparent mode and the light transmittance in the opaque mode. In other words, in the halftone mode, the haze of the light control sheet 10 has a size between the haze in the transparent mode and the haze in the opaque mode, and a partial difference in the haze occurs to cause a light control sheet. 10 presents the pattern.

In the halftone mode, the light transmittance of at least one of the region with the highest light transmittance and the region with the lowest light transmittance of the light control sheet 10 is the light transmittance in the transparent mode and the light transmittance in the opaque mode. The size may be between and. In both the normal type and the reverse type, the magnitude of the driving voltage applied to the transparent electrode layers 12A and 12B in the halftone mode is between the driving voltage in the transparent mode and the driving voltage in the opaque mode. That's it.

3 shows an example of the transparent mode light control sheet 10, FIG. 4 shows an example of the intermediate mode light control sheet 10, and FIG. 5 shows an example of the opaque mode light control sheet 10. In each of the transparent mode and the opaque mode, the light control sheet 10 does not exhibit a pattern. The pattern that the light control sheet 10 presents in the halftone mode is not particularly limited, and is, for example, a picture, a regular or irregular pattern, a figure, a character, a symbol, or a combination thereof. FIG. 4 exemplifies a shoji-tone pattern showing how fibers are dispersed.

In the halftone mode, the light control sheet 10 may be composed of two regions, a region having a high light transmittance and a region having a low light transmittance, or may be composed of three or more regions having different light transmittances. .. In other words, in the light control sheet 10, the light transmittance may be changed in two steps, or may be changed stepwise or continuously in three or more steps.

The control unit 20 of the light control device drives between the transparent mode, the halftone mode, and the opaque mode by changing the magnitude of the drive voltage applied to the light control sheet 10, that is, the effective value of the AC voltage. Change the mode. These modes may be switched instantaneously, or the modes may be continuously transitioned such that the light transmittance of the light control sheet 10 is gradually changed by gradually increasing or decreasing the driving voltage. .. Further, in the halftone mode, by changing the magnitude of the driving voltage and changing the light transmittance of each region in two or more steps, the halftone mode shows the same pattern due to the difference in light transmittance. , A plurality of states having different overall transparency may be included.

The plurality of regions having different light transmittances are configured such that the relationship between the driving voltage and the polarization direction of the liquid crystal molecules included in the light control layer 11 is different between these regions. The polarization direction of the liquid crystal molecules is the average direction of the major axis directions of many liquid crystal molecules included in the light control layer 11. In the transparent mode and the opaque mode, the control unit 20 sets the magnitude of the driving voltage to a value that makes the polarization direction equal between the regions, and in the halftone mode, makes the polarization direction different between the regions. .. As a result, in the halftone mode, a difference in light transmittance occurs between the regions, and the light control sheet 10 exhibits a pattern caused by the difference in light transmittance.

Hereinafter, five modes will be described with respect to a specific configuration for producing a difference in light transmittance in the light control sheet 10 and a manufacturing method thereof. In the following description, the light control sheets 10a to 10e of the respective embodiments have the same layer structure as the normal type light control sheet 10N or the reverse type light control sheet 10R described above, and light in the intermediate tone mode. Each form has different characteristics for producing a difference in transmittance. These features will be described in detail in the following description of each embodiment.

[First form]
As shown in FIG. 6, in the light control sheet 10a of the first embodiment, the thickness of the light control layer 11 is partially different. Then, in the halftone mode, due to the difference in the thickness of the light control layer 11, a difference in light transmittance occurs in the light control sheet 10a, and the pattern is visually recognized.

As an example, a case where the light control sheet 10a has a first region R1a in which the light control layer 11 is relatively thick and a second region R2a in which the light control layer 11 is relatively thin will be described. Although the reverse type is illustrated in FIG. 6, the first form is also applicable to the normal type.

FIG. 7 is a graph showing the relationship between the applied voltage and the haze in the first region R1a and the second region R2a for the reverse type light control sheet 10a including the light control layer 11 composed of the polymer network liquid crystal. .. The applied voltage indicates the magnitude of the drive voltage applied by the control unit 20 to the terminal portions 15A and 15B.

As shown in FIG. 7, in the region where the applied voltage is 0 V or more and less than the first threshold value V1, there is a difference in haze between the first region R1a where the dimming layer 11 is thick and the second region R2a where the dimming layer 11 is thin. Even if the applied voltage is increased/decreased, the haze is almost unchanged near the minimum value. That is, the polarization directions of the liquid crystal molecules included in the light control layer 11 are the same in the first region R1a and the second region R2a. Therefore, the transparent mode is realized by applying a drive voltage of 0 V or more and less than the first threshold V1. In the transparent mode, there is no visible difference in light transmittance between the first region R1a and the second region R2a, and the pattern is not visible.

In the region where the applied voltage is equal to or more than the first threshold value V1 and less than the second threshold value V2, a difference in haze occurs between the first region R1a and the second region R2a. That is, the polarization directions of the liquid crystal molecules included in the light control layer 11 are different between the first region R1a and the second region R2a. In both the first region R1a and the second region R2a, the haze increases as the applied voltage increases.

Since the light control layer 11 in the second region R2a is thinner than in the first region R1a, the diffusion of light transmitted through the light control sheet 10a is small in the second region R2a. Further, even if the common drive voltage is applied to the first region R1a and the second region R2a, the effective voltage applied to the light control layer 11 in the second region R2a is larger than that in the first region R1a. In the reverse type, the larger the effective voltage, the greater the force that directs the long axis direction of the liquid crystal molecules in a direction different from the normal direction of the alignment layers 14A and 14B. Therefore, with respect to the rise of the common drive voltage, the haze rises earlier in the second region R2a than in the first region R1a. The decrease in light diffusion in the second region R2a and the increase in effective voltage have contradictory effects on the increase and decrease in light transmittance and haze in the second region R2a, but the effective voltage is large. The effect of becoming larger is greater. Therefore, in the reverse type, when the driving voltage of the first threshold value V1 or more and less than the second threshold value V2 is applied, the second region R2a has a lower light transmittance than the first region R1a and has a haze. Becomes higher. Thereby, the halftone mode is realized, and the pattern resulting from the difference in the light transmittance between the first region R1a and the second region R2a is visually recognized.

In the region where the applied voltage is equal to or higher than the second threshold value V2, there is no difference in the haze between the first region R1a and the second region R2a, and even if the applied voltage increases or decreases, the haze is saturated and almost changes near the maximum value. Absent. That is, the polarization directions of the liquid crystal molecules included in the light control layer 11 are the same in the first region R1a and the second region R2a. Therefore, the opaque mode is realized by applying the drive voltage equal to or higher than the second threshold value V2. In the opaque mode, there is no visible difference in light transmittance between the first region R1a and the second region R2a, and the pattern is not visible.

On the other hand, in the case of the normal type, the opaque mode is realized by applying a drive voltage of 0 V or more and less than the first threshold V1 in which the haze is almost unchanged near the maximum value. In the opaque mode, there is no visible difference in light transmittance between the first region R1a and the second region R2a, and the pattern is not visible.

In the region where the applied voltage is equal to or more than the first threshold value V1 and less than the second threshold value V2, a difference in haze occurs between the first region R1a and the second region R2a. In both the first region R1a and the second region R2a, the haze decreases as the applied voltage increases. In the normal type, the larger the effective voltage, the larger the force for orienting the long axis direction of the liquid crystal molecules in the direction of the electric field between the transparent electrode layers 12A and 12B, that is, the normal direction of the light control layer 11. Therefore, the haze of the second region R2a is reduced faster than that of the first region R1a with respect to the increase of the common drive voltage. Therefore, since the diffusion of light in the second region R2a is small and the effective voltage is large, the second region R2a has a higher light transmittance and a lower haze than the first region R1a. Become. Therefore, by applying the drive voltage that is equal to or more than the first threshold value V1 and less than the second threshold value V2, the halftone mode is realized, and the pattern caused by the difference in the light transmittance between the first region R1a and the second region R2a is visually recognized. To be done.

Then, the transparent mode is realized by applying a drive voltage equal to or higher than the second threshold V2 at which the haze is almost unchanged near the minimum value. In the transparent mode, there is no visible difference in light transmittance between the first region R1a and the second region R2a, and the pattern is not visible.

It should be noted that by applying drive voltages of the first threshold value V1 or more and less than the second threshold value V2 and different magnitudes from each other, a plurality of pixels having different patterns of different transparency while exhibiting the same pattern due to the difference in light transmittance. State can be expressed. For example, the dimming sheet 10a exhibits the same pattern when the voltage Va shown in FIG. 7 is applied and when the voltage Vb larger than the voltage Va is applied, but the first region R1a and the second region R2a. In both cases, the haze is higher when the voltage Vb is applied. That is, the transparency becomes lower when the voltage Vb is applied.

A method of manufacturing the light control sheet 10a of the first embodiment will be described. The light control sheet 10a of the first embodiment is formed by pressing the above-described light control sheet multilayer body with a plate having irregularities corresponding to a desired pattern. By the pressing with the plate, a difference in thickness of the light control layer 11 is formed. Specifically, a multilayer body for a light control sheet is provided between a first roll having irregularities corresponding to the above pattern and a second roll arranged so as to face the first roll and having no irregularities on the surface. Then, the multilayer body for light control sheet is pressed by these two rolls. As a result, the unevenness of the first roll is transferred to the multilayer body for a light control sheet. That is, the light control layer 11 of the multilayer body for a light control sheet is crushed at the portion that contacts the convex portion of the first roll, and the second region R2a is formed.

Here, the structure of the multilayer body for a light control sheet, which is suitable for manufacturing the light control sheet 10a of the first embodiment, will be described.
FIG. 8 shows a light control sheet multilayer body 30 used to form the reverse type light control sheet 10a of the first embodiment. The light control sheet multilayer body 30 is a laminated body before the difference in thickness of the light control layer 11 is formed, and includes the light control layer 11, the transparent electrode layers 12A and 12B, the transparent support layers 13A and 13B, and , Alignment layers 14A and 14B.

When a polymer film such as polyethylene terephthalate is used as the transparent support layers 13A and 13B, the thickness Ts of each of the first transparent support layer 13A and the second transparent support layer 13B is usually 50 μm or more and 200 μm or less. is there. The thickness Tl of the light control layer 11 made of the polymer network type liquid crystal is usually about 10 μm or more and 15 μm or less.

In the light control sheet multilayer body 30 used for manufacturing the light control sheet 10a of the first embodiment, in order to easily form a difference in thickness of the light control layer 11 by pressing with the above-mentioned plate, in other words, pressing force is applied. It is preferable to use the thin transparent support layers 13A and 13B in the above range and the thick light control layer 11 in the above range so that the light can easily act on the light control layer 11. Specifically, for example, the thickness Ts of the transparent support layers 13A and 13B is 50 μm, and the thickness Tl of the light control layer 11 is 15 μm. When the thin transparent support layers 13A and 13B and the thick light control layer 11 are used in terms of the thickness of these layers, the thickness Tl of the light control layer 11 is equal to the thickness of the transparent support layers 13A and 13B. It is preferably 1/3 or more of the length Ts.

The thickness relationship between the light control layer 11 and the transparent support layers 13A and 13B is also applied to the light control sheet multilayer body 30 used to form the normal type first light control sheet 10a. ..

As described above, in the first embodiment, a region in which the relationship between the drive voltage and the polarization direction of the liquid crystal molecules included in the light control layer 11 is different due to the difference in the thickness of the light control layer 11, specifically, the drive voltage is increased. In this case, a region in which the magnitude of the voltage at which the light transmittance and the haze start to change when they are made different is generated. The thickness of the light control layer 11 is not limited to two levels and may be changed in three or more levels. Note that the light control sheet 10 is not limited to the case where the light control layer 11 includes the polymer network liquid crystal, and the light transmission can be achieved by changing the direction of liquid crystal molecules included in the light control layer 11 by applying a driving voltage. With the light control sheet 10 that changes the ratio, the light control sheet 10 having a pattern can be realized by applying the first embodiment.

[Second form]
As shown in FIG. 9, the light control sheet 10b of the second embodiment is a reverse type, and the thicknesses of the alignment layers 14A and 14B are partially different. Then, in the halftone mode, due to the difference in thickness of the alignment layers 14A and 14B, a difference in light transmittance occurs in the light control sheet 10b, and the pattern is visually recognized.

As an example, a case where the light control sheet 10b has a first region R1b in which the alignment layers 14A and 14B are relatively thick and a second region R2b in which the alignment layers 14A and 14B are relatively thin will be described. In the second region R2b, at least one of the first alignment layer 14A and the second alignment layer 14B is thinner than the first region R1b.

The thinner the alignment layers 14A and 14B, the smaller the regulation force of the liquid crystal molecules by the alignment layers 14A and 14B. That is, in the second region R2b, the force for aligning the long axis direction of the liquid crystal molecules in the normal direction of the alignment layers 14A and 14B is smaller than that in the first region R1b. Therefore, with respect to the rise of the common drive voltage, the haze rises earlier in the second region R2b than in the first region R1b.

Similar to the first embodiment, the transparent mode is realized by applying the drive voltage in the low voltage region in which the haze is almost unchanged near the minimum value even if the applied voltage is increased or decreased. Further, even if the applied voltage is increased or decreased, the haze is saturated, and the opaque mode is realized by applying the drive voltage in a high voltage region where the haze is almost unchanged near the maximum value. In the transparent mode and the opaque mode, there is no visible difference in light transmittance between the first region R1b and the second region R2b, and the pattern is not visible.

On the other hand, by applying the drive voltage in the region between the low voltage region and the high voltage region, a difference in haze occurs between the first region R1b and the second region R2b, and the halftone mode is realized. That is, as described above, due to the difference in the thickness of the alignment layers 14A and 14B, the haze increases faster in the second region R2b than in the first region R1b with respect to the increase in the applied voltage. , The second region R2b has a lower light transmittance and a higher haze than the first region R1b. Thereby, the pattern resulting from the difference in light transmittance between the first region R1b and the second region R2b is visually recognized.

The light control sheet 10b of the second mode is formed by pressing the multilayer body for a light control sheet described above with a plate having irregularities corresponding to a desired pattern, as in the first mode.
In the light control sheet multilayer body used for manufacturing the light control sheet 10b of the second embodiment, in order to easily form a difference in thickness between the alignment layers 14A and 14B by pressing with the plate, in other words, pressing force is applied. It is preferable to use thin transparent support layers 13A and 13B having a thickness of, for example, about 50 μm so that the film easily acts on the alignment layers 14A and 14B.

In addition, in which layer the difference in thickness is formed by pressing, in addition to adjusting the material and thickness of each layer, by sealing the end of the multilayer body for light control sheet, the pressure inside each layer It can also be controlled by adjustment or the like.

As described above, in the second embodiment, a region where the relationship between the drive voltage and the polarization direction of the liquid crystal molecules included in the light control layer 11 is different due to the difference in the thickness of the alignment layers 14A and 14B, specifically, the drive voltage is changed. Regions with different voltage magnitudes at which the light transmittance and haze start to change when raised are created. The thickness of each of the first alignment layer 14A and the second alignment layer 14B is not limited to two levels, but may be changed in three or more levels.

[Third mode]
As shown in FIG. 10, in the light control sheet 10c of the third embodiment, the transparent electrode layers 12A and 12B have partially different thicknesses. Then, in the halftone mode, due to the difference in thickness of the transparent electrode layers 12A and 12B, a difference in light transmittance occurs in the light control sheet 10c, and the pattern is visually recognized.

As an example, the case where the light control sheet 10c has a first region R1c in which the transparent electrode layers 12A and 12B are relatively thick and a second region R2c in which the transparent electrode layers 12A and 12B are relatively thin will be described. In the second region R2c, at least one of the first transparent electrode layer 12A and the second transparent electrode layer 12B is thinner than the first region R1c. Although the reverse type is illustrated in FIG. 10, the third mode is also applicable to the normal type.

The thinner the transparent electrode layers 12A and 12B, the smaller the effective voltage applied to the light control layer 11 due to the increase in the resistance of the transparent electrode layers 12A and 12B. Therefore, in the case of the reverse type, in the second region R2c, the force that directs the major axis direction of the liquid crystal molecules in a direction different from the normal direction of the alignment layers 14A and 14B is smaller than that in the first region R1c. Therefore, the increase in haze occurs later in the second region R2c than in the first region R1c with respect to the increase in the common drive voltage.

In the case of the reverse type, the transparent mode is realized by applying the driving voltage in the low voltage region, and the opaque mode is realized by applying the driving voltage in the high voltage region. In the transparent mode and the opaque mode, there is no visible difference in light transmittance between the first region R1c and the second region R2c, and the pattern is not visible.

Then, by applying the drive voltage in a region between the low voltage region and the high voltage region, a difference in haze occurs between the first region R1c and the second region R2c, and the halftone mode is realized. That is, as described above, due to the difference in the thickness of the transparent electrode layers 12A and 12B, the increase in haze is slower in the second region R2c than in the first region R1c with respect to the increase in applied voltage. , The second region R2c has a higher light transmittance and a lower haze than the first region R1c. Thereby, the pattern resulting from the difference in light transmittance between the first region R1c and the second region R2c is visually recognized.

On the other hand, in the case of the normal type, the effective voltage applied to the light control layer 11 in the second region R2c is smaller than that in the first region R1c, so that the long axis direction of the liquid crystal molecules is directed to the transparent electrode layers 12A and 12B. The force along the electric field direction, that is, the normal direction of the light control layer 11 becomes small. Therefore, the decrease in haze occurs later in the second region R2c than in the first region R1c with respect to the increase in the common drive voltage.

In the case of the normal type, the opaque mode is realized by applying the driving voltage in the low voltage region, and the transparent mode is realized by applying the driving voltage in the high voltage region. In the transparent mode and the opaque mode, there is no visible difference in light transmittance between the first region R1c and the second region R2c, and the pattern is not visible.

Then, by applying the drive voltage in a region between the low voltage region and the high voltage region, a difference in haze occurs between the first region R1c and the second region R2c, and the halftone mode is realized. That is, as described above, due to the difference in thickness of the transparent electrode layers 12A and 12B, the haze in the second region R2c is slower than that in the first region R1c with respect to the increase in the applied voltage. , The second region R2c has a lower light transmittance and a higher haze than the first region R1c. Thereby, the pattern resulting from the difference in light transmittance between the first region R1c and the second region R2c is visually recognized.

The light control sheet 10c of the third mode is formed by pressing the multilayer body for a light control sheet with a plate having irregularities corresponding to a desired pattern, as in the first mode.
In the light control sheet multilayer body used for manufacturing the third embodiment of the light control sheet 10c, in order to easily form a difference in thickness between the transparent electrode layers 12A and 12B by pressing with the plate, in other words, pressing It is preferable to use thin transparent support layers 13A and 13B having a thickness of, for example, about 50 μm so that the pressure easily acts on the transparent electrode layers 12A and 12B. Further, it is preferable that the transparent electrode layers 12A and 12B have high flexibility so that the transparent electrode layers 12A and 12B are easily deformed by pressing with the plate. Specifically, the transparent electrode layers 12A and 12B are preferably made of an organic material such as PEDOT.

As described above, in the third embodiment, a region where the relationship between the driving voltage and the polarization direction of the liquid crystal molecules included in the light control layer 11 is different due to the difference in the thickness of the transparent electrode layers 12A and 12B, specifically, the driving voltage. Causes a region in which the magnitude of the voltage at which the light transmittance and the haze start to change when is increased. The thickness of each of the first transparent electrode layer 12A and the second transparent electrode layer 12B is not limited to two levels, but may be changed in three or more levels.

[Fourth form]
As shown in FIG. 11, the light control sheet 10d of the fourth embodiment includes a light control layer 11 composed of a polymer network type liquid crystal, and in the light control layer 11, the density of the polymer forming the polymer network is partially. Differently. Then, in the halftone mode, a difference in light transmittance occurs in the light control sheet 10d due to a difference in polymer density, and the pattern is visually recognized.

As an example, the case where the light control sheet 10d has a first region R1d having a relatively high polymer density and a second region R2d having a relatively low polymer density will be described. Although the reverse type is illustrated in FIG. 10, the fourth mode is also applicable to the normal type.

The polymer that constitutes the polymer network may have no regulating power for the alignment of the liquid crystal molecules or may have a regulating power for the alignment. When the polymer does not have the above-mentioned regulation power, the polymer has no directionality and forms a disordered network network. When the polymer has the above-mentioned regulation force, the polymer forms a network so that the polymer chains extend along a specific direction. Such regulatory force can be controlled by the presence or absence of polarity in the polymer.

First, the case where the polymer does not have the regulation power will be described. In this case, the lower the density of the polymer, the larger the network of the polymer network, and the liquid crystal molecules held in the voids are likely to change the direction. Therefore, the change in haze occurs faster in the second region R2d than in the first region R1d with respect to the increase in the common drive voltage.

In the case of the reverse type, the transparent mode is realized by applying the driving voltage in the low voltage region, and the opaque mode is realized by applying the driving voltage in the high voltage region. In the transparent mode and the opaque mode, there is no visible difference in light transmittance between the first region R1d and the second region R2d, and the pattern is not visible.

Then, by applying the drive voltage in a region between the low voltage region and the high voltage region, a difference in haze occurs between the first region R1d and the second region R2d, and the halftone mode is realized. That is, as described above, due to the difference in polymer density in the light control layer 11, the haze rises faster in the second region R2d than in the first region R1d with respect to the increase in the applied voltage. The second region R2d has a lower light transmittance and a higher haze than the first region R1d. Thereby, the pattern resulting from the difference in light transmittance between the first region R1d and the second region R2d is visually recognized.

In the case of the normal type, the opaque mode is realized by applying the driving voltage in the low voltage region, and the transparent mode is realized by applying the driving voltage in the high voltage region. In the transparent mode and the opaque mode, there is no visible difference in light transmittance between the first region R1d and the second region R2d, and the pattern is not visible.

Then, by applying the drive voltage in a region between the low voltage region and the high voltage region, a difference in haze occurs between the first region R1d and the second region R2d, and the halftone mode is realized. That is, as described above, due to the difference in the polymer densities in the light control layer 11, the haze in the second region R2d decreases earlier than in the first region R1d with respect to the increase in the applied voltage. The second region R2d has a higher light transmittance and a lower haze than the first region R1d. Thereby, the pattern resulting from the difference in light transmittance between the first region R1d and the second region R2d is visually recognized.

Next, the case where the polymer has a regulation force will be described. The polymer has a restricting force in the direction in which the long axis direction of the liquid crystal molecules is oriented as the applied voltage rises. That is, in the case of the reverse type, the polymer is designed so that the polymer chain extends in a direction different from the normal direction of the alignment layers 14A and 14B, for example, a direction orthogonal to the normal direction. In the case of the normal type, the polymer is designed so that the polymer chain extends in the direction of the electric field between the transparent electrode layers 12A and 12B, that is, the normal direction of the light control layer 11. In these cases, the lower the density of the polymer, the weaker the regulation force of the polymer becomes, and it becomes difficult for the liquid crystal molecules to turn in the direction in which the regulation force works. Therefore, the change in the haze occurs more slowly in the second region R2d than in the first region R1d with respect to the rise in the common drive voltage.

In the case of the reverse type, similar to the case where the above-mentioned polymer does not have the regulation force, the transparent mode is applied when the driving voltage is applied in the low voltage region, and the opaque mode is applied when the driving voltage is applied in the high voltage region. ..

Then, by applying the drive voltage in a region between the low voltage region and the high voltage region, a difference in haze occurs between the first region R1d and the second region R2d, and the halftone mode is realized. That is, due to the difference in the polymer density in the light control layer 11, the haze increase occurs in the second region R2d later than in the first region R1d with respect to the increase in the applied voltage. The second region R2d has higher light transmittance and lower haze than R1d. Thereby, the pattern resulting from the difference in light transmittance between the first region R1d and the second region R2d is visually recognized.

In the case of the normal type, as in the case where the above-mentioned polymer does not have the restriction force, the opaque mode is set when the driving voltage is applied in the low voltage region, and the transparent mode is set when the driving voltage is applied in the high voltage region. ..

Then, by applying the drive voltage in a region between the low voltage region and the high voltage region, a difference in haze occurs between the first region R1d and the second region R2d, and the halftone mode is realized. That is, due to the difference in the polymer density in the light control layer 11, the decrease in haze occurs later in the second region R2d than in the first region R1d with respect to the increase in the applied voltage. The second region R2d has a lower light transmittance and a higher haze than the R1d. Thereby, the pattern resulting from the difference in light transmittance between the first region R1d and the second region R2d is visually recognized.

A method for manufacturing the light control sheet 10d according to the fourth mode will be described. In the light control sheet 10d of the fourth embodiment, in the step of irradiating the coating layer with the ultraviolet light described in the method for manufacturing the light control sheet 10 described above, the cumulative light amount of the ultraviolet light irradiated per unit area is partially different. It is formed. In the portion where the integrated light amount is relatively large, the polymerization proceeds and the density of the polymer becomes relatively large. As a result, the light control layer 11 having partially different polymer densities is formed, and as a result, the light control sheet 10d having the first region R1d and the second region R2d is formed. The first region R1d and the second region R2d have different ratios of the polymer to the monomer.

As described above, in the fourth embodiment, a region where the relationship between the drive voltage and the polarization direction of the liquid crystal molecules included in the light control layer 11 is different due to the difference in the polymer density in the light control layer 11, specifically, the drive voltage is changed. Regions with different voltage magnitudes at which the light transmittance and haze start to change when raised are created. The density of the polymer in the light control layer 11 may be changed in multiple stages. Not only the case where the light control layer 11 is composed of the polymer network type liquid crystal, but the light control sheet 10 including the light control layer 11 that holds liquid crystal molecules between the polymers can be obtained by applying the fourth embodiment. It is possible to realize the light control sheet 10 having a pattern.

[Fifth form]
As shown in FIG. 12, the light control sheet 10e of the fifth embodiment is a reverse type, and the cured states of the alignment layers 14A and 14B are partially different. Then, in the halftone mode, due to the difference in the cured state of the alignment layers 14A and 14B, a difference in light transmittance occurs in the light control sheet 10e, and the pattern is visually recognized.

As an example, the light control sheet 10e includes a first region R1e in which the alignment layers 14A and 14B have not been relatively cured, and a second region R2e in which the alignment layers 14A and 14B have been relatively cured. A case will be described. In the second region R2e, at least one of the first alignment layer 14A and the second alignment layer 14B is harder than the first region R1e.

The more the alignment layers 14A and 14B are dried and hardened, that is, the harder the alignment layers 14A and 14B are, the higher the density of molecules constituting the alignment layers 14A and 14B becomes, and the liquid crystal formed by the alignment layers 14A and 14B is increased. The regulatory power of the molecule increases. That is, in the second region R2e, the force that causes the long axis direction of the liquid crystal molecules to follow the normal direction of the alignment layers 14A and 14B is larger than that in the first region R1e. Therefore, the increase in haze occurs later in the second region R2e than in the first region R1e with respect to the increase in the common drive voltage.

Also in the fifth mode, the transparent mode is realized by applying the drive voltage in the low voltage region, and the opaque mode is realized by applying the drive voltage in the high voltage region. In the transparent mode and the opaque mode, there is no visible difference in light transmittance between the first region R1e and the second region R2e, and the pattern is not visible.

Then, by applying the drive voltage in the region between the low voltage region and the high voltage region, a difference in haze occurs between the first region R1e and the second region R2e, and the halftone mode is realized. That is, due to the difference in the cured state of the alignment layers 14A and 14B, the haze rise is slower in the second region R2e than in the first region R1e with respect to the applied voltage rise. Also, in the second region R2e, the light transmittance is higher and the haze is lower. Thereby, the pattern caused by the difference in light transmittance between the first region R1e and the second region R2e is visually recognized.

A method for manufacturing the light control sheet 10e of the fifth mode will be described. The light control sheet 10e of the fifth embodiment is a method for manufacturing the light control sheet 10 described above, in which when the alignment layers 14A and 14B are formed by drying the coating film, the heat quantity of the warm air supplied per unit area is partially adjusted. It is formed by making them different from each other. In a portion where the amount of heat is relatively large, curing by drying progresses more. As a result, the alignment layers 14A and 14B having partially different cured states are formed, and as a result, the light control sheet 10e having the first region R1e and the second region R2e is formed.

As described above, in the fifth embodiment, a region in which the relationship between the driving voltage and the polarization direction of the liquid crystal molecules included in the dimming layer 11 differs due to the difference in the curing state between the alignment layers 14A and 14B, specifically, the driving voltage is changed. Regions with different voltage magnitudes at which the light transmittance and haze start to change when raised are created. The hardening state of each of the first alignment layer 14A and the second alignment layer 14B may be changed in multiple stages.

[Other forms]
The above-described first to fifth forms may be combined with each other. For example, when the first mode and the third mode are combined, due to the difference in the thickness of the light control layer 11 and the difference in the thickness of the transparent electrode layers 12A and 12B, the driving voltage and the polarization direction of the liquid crystal molecules are caused. A region having a different relationship with is formed. This causes a difference in light transmittance in the light control sheet 10, and the pattern is visually recognized.

In addition, the light control device causes a difference in the light transmittance in the light control sheet 10 due to the difference in the relationship between the magnitude of the drive voltage applied to the transparent electrode layers 12A and 12B and the polarization direction of the liquid crystal molecules of the light control layer 11. The structure of the light control device may be different from that of the first to fifth modes as long as it is generated and exhibits a pattern. Furthermore, if the light control sheet 10 having the above configuration can be formed, the light control sheet 10 may be manufactured by a method different from the manufacturing method illustrated in each of the above-described embodiments.

For example, by orienting liquid crystal molecules using an orientation layer, a normal type, that is, a type of dimmer sheet that is opaque when a driving voltage is not applied and becomes transparent as the driving voltage increases is realized. May be.

Further, it is possible to enhance the designability of the light control sheet as long as it is a light control device that implements at least the halftone mode among the transparent mode, the opaque mode, and the halftone mode. Further, the driving mode of the light control sheet is not limited to a mode in which no pattern appears on the light control sheet in the state of lowest transparency. In a state where the transparency is the lowest, it is also possible to adopt a form having a design that allows the pattern to remain and be recognized while maximizing the function as a partition.

[Application example]
A configuration applicable when the above-mentioned light control sheet 10 is used as a partition member that partitions two spaces by adhering it to a window glass or the like will be described.

As shown in FIG. 13, the light control sheet 10 may include a partitioning member 40 on its surface that partitions a region of the surface of the light control sheet 10. The partitioning members 40 are arranged in a grid shape extending in the vertical and horizontal directions, for example, like a shoji frame, and partition the surface of the light control sheet 10 into a plurality of rectangular regions. The partition member 40 is made of, for example, a decorative tape made of resin or the like, and is attached to the surface of the light control sheet 10.

When the light control sheet 10 has a shoji pattern and the partition member 40 is arranged so as to form a shoji frame, the light control sheet 10 can be used as a substitute for the shoji. By switching between the transparent mode and the halftone mode, it is possible to realize a state in which the shoji screen is opened and a state in which the shoji screen is closed are alternatives.

In a house or the like, in order to place a real shoji at a place where there is a window, it is necessary to place a sill and a duck for a shoji adjacent to the sash of the window, or to provide an edge. Therefore, the construction for arranging shoji screens becomes large-scale work, and it is often difficult to secure a space for arranging shoji screens in modern houses. On the other hand, although the curtains can be easily arranged, it is difficult to match the atmosphere of a Japanese room.

On the other hand, since the light control sheet 10 can be used by being attached to the window glass, the load and space required for the placement are smaller than that of the shoji screen. Therefore, by using the light control sheet 10 as an alternative to the shoji, even in a place where the shoji is difficult to arrange, like the shoji, the dimming effect of taking in light while protecting the privacy and the decorative effect suitable for a Japanese-style room It is possible to arrange a partition member having a.

In addition, shoji paper is easy to tear and easily deteriorates. Therefore, in the shoji screen, it is necessary to replace the shoji paper for maintenance, but if the light control sheet 10 is used as a substitute for the shoji screen, the load required for such maintenance can be reduced.

Further, in one or more regions of the plurality of regions partitioned by the partition member 40, the drive mode may be controllable independently of the other regions. In the target area where the drive mode can be controlled independently, at least one of the first transparent electrode layer 12A and the second transparent electrode layer 12B is insulated from other areas, and is separate from the other areas. A drive voltage is applied. It is preferable that the terminal portion and the wiring for applying the drive voltage to the target region are arranged in a portion overlapping the partition member 40. If there is no problem in terms of dimensions, it is possible to provide an opening space in a frame, a braid or the like corresponding to the partitioning member 40, and dispose the wiring or the like in the space. As a result, it is possible to prevent the terminal portion and the wiring from being visually recognized when viewed from the position facing the surface of the light control sheet 10, so that the design of the light control sheet 10 is further enhanced.

For example, as shown in FIG. 14, the target region C1 at the bottom can control the drive mode independently of the other regions C2. In this case, for example, by setting the target region C1 in the transparent mode and setting the other region C2 in the halftone mode, the light control sheet 10 can be used as a substitute for the snow shoji. As described above, if independent drive modes can be controlled in one or more areas partitioned by the partitioning member 40, various decorative effects can be obtained by selecting the drive mode in each area. It is also possible to adjust the amount of light taken from one space divided by the light control sheet 10 into the other space by selecting the drive mode of each area.

Instead of the partition member 40, the pattern presented by the light control sheet 10 may include a portion imitating a shoji frame. In other words, the light control sheet 10 may exhibit a pattern including a grid-like pattern imitating a shoji frame, depending on the difference in light transmittance.

The surface to which the light control sheet 10 is attached may be a flat surface or a curved surface. The target to which the light control sheet 10 is attached is not limited to a building material such as a window glass or a glass wall, but may be a vehicle member such as a window glass of an automobile.

As described above, according to this embodiment, the effects listed below can be obtained.
(1) The light control sheet 10 has regions where the relationship between the magnitude of the drive voltage applied to the transparent electrode layers 12A and 12B and the polarization direction of the liquid crystal molecules included in the light control layer 11 is different. Then, when a driving voltage having a magnitude that makes the polarization direction different between these regions is applied, a difference in light transmittance occurs in the light control sheet 10. As a result, the light control sheet 10 exhibits a pattern due to the difference in light transmittance, so that the design of the light control sheet 10 is enhanced.

(2) A mode in which the difference in the relationship is caused by the difference in the thickness of the light control layer 11, a mode in which the difference in the relationship is caused by the difference in the thickness of the transparent electrode layers 12A and 12B, and the alignment layer 14A , 14B in each of the forms in which the difference in the relationship is caused by the difference in the thickness, the light control sheet 10 having the pattern caused by the difference in the light transmittance is preferably realized. Further, such a light control sheet 10 can be formed by pressing a multilayer body for a light control sheet with a mold. That is, the light control sheet 10 can be formed so as to exhibit a desired pattern after the layers are stacked. Therefore, the multilayer body for a light control sheet can be formed and stored as a member common to various patterns, and the multilayer body for a light control sheet can be shipped as a light control sheet without a pattern. Therefore, even when the light control sheet 10 having various patterns is manufactured, the inventory can be compressed and the manufacturing cost can be reduced.

(3) Each of the form in which the difference in the relationship is caused due to the difference in the polymer density in the light control layer 11 and the form in which the difference is caused due to the difference in the curing state in the alignment layers 14A and 14B. For example, the light control sheet 10 having a pattern caused by the difference in light transmittance is preferably realized.

(4) Drive mode between the halftone mode in which the light control sheet 10 exhibits a pattern and the transparent mode in which the light control sheet 10 is transparent and does not exhibit a pattern by controlling the magnitude of the drive voltage by the control unit 20. Can be changed. Further, by controlling the magnitude of the drive voltage by the control unit 20, the drive mode can be changed between the halftone mode and the opaque mode in which the light control sheet 10 is opaque and does not exhibit a pattern. According to these configurations, it is possible to change the decoration of the space facing the light control sheet 10 by changing the drive mode, and various light decoration effects by the light control sheet 10 can be obtained. Further, by changing the drive mode, it is possible to adjust the amount of light taken from one space divided by the light control sheet 10 to the other space. If the drive mode can be changed among the transparent mode, the halftone mode, and the opaque mode, the decorative effect and the dimming effect can be further diversified.

[Appendix]
Means for solving the above problems include the following supplementary notes as technical ideas derived from the above embodiments.

A light control layer containing liquid crystal molecules,
A pair of transparent electrode layers sandwiching the light control layer,
A pair of transparent support layers sandwiching the light control layer and the pair of transparent electrode layers,
A multilayer body for a light control sheet comprising:
The thickness of the light control layer is 1/3 or more of the thickness of the transparent support layer,
The multilayer body for a light control sheet is used for forming a light control sheet having a plurality of regions having different thicknesses of the light control layer by pressing the multilayer body.

According to the multilayer body for a light control sheet, since a thin transparent support layer and a thick light control layer are used as compared with a general thickness relationship between the light control layer and the transparent support layer, it is possible to adjust by pressing. A difference in the thickness of the optical layer is likely to be formed. Therefore, by forming a light control sheet using such a multilayer body for a light control sheet, a light control sheet exhibiting a pattern is produced by causing a difference in light transmittance due to a difference in the thickness of the light control layer. To be done. Therefore, it is possible to form a light control sheet having a high design property.

10, 10a, 10b, 10c, 10d, 10e, 10N, 10R... Light control sheet, 11... Light control layer, 12A, 12B... Transparent electrode layer, 13A, 13B... Transparent support layer, 14A, 14B... Alignment layer, 15A , 15B... Terminal part, 20... Control part, 30... Multilayer body for light control sheet, 40... Partitioning member.

Claims (10)

A light control layer including liquid crystal molecules, and a light control sheet including a pair of transparent electrode layers sandwiching the light control layer,
A control unit for controlling the magnitude of the voltage applied between the transparent electrode layers,
The light control sheet includes a plurality of regions configured such that the relationship between the voltage and the polarization direction of the liquid crystal molecules is different between the regions.
The control unit changes the magnitude of the voltage into a magnitude that makes the polarization directions equal between the regions and a magnitude that makes the polarization directions different between the regions. The control unit controls the magnitude of the voltage so that the polarization direction is the same between the regions and the light control sheet is transparent, and the polarization direction is different between the regions. Changing the mode of the light control sheet between a halftone mode in which the pattern is caused by a difference in light transmittance and an opaque mode in which the polarization directions are equal between the regions and the light control sheet is opaque. 1. The light control device according to 1. 3. The light control sheet according to claim 1, wherein in the light control sheet, the relationship between the magnitude of the voltage and the polarization direction of the liquid crystal molecules is different between the regions because the thickness of the light control layer is different between the regions. Light equipment. A pair of transparent support layers sandwiching the light control layer and the pair of transparent electrode layers are provided, and the thickness of the light control layer in the thickest region of the light control layer is 1/3 of the thickness of the transparent support layer. The above is the light control device according to claim 3. In the light control sheet, in at least one of the pair of transparent electrode layers, the relationship between the magnitude of the voltage and the polarization direction of the liquid crystal molecules is different between the regions because the thickness of the transparent electrode layers is different between the regions. The light control device according to claim 1 or 2, wherein The light control sheet comprises a pair of alignment layers sandwiching the light control layer, the pair of transparent electrode layers sandwich the light control layer and the pair of alignment layers, at least one of the pair of alignment layers, The light control device according to claim 1, wherein the relationship between the magnitude of the voltage and the polarization direction of the liquid crystal molecules differs between the regions because the thickness of the alignment layer differs between the regions. The said light control sheet WHEREIN: The relationship of the magnitude|size of the said voltage and the polarization direction of the said liquid crystal molecule differs between the said areas by the density of the polymer in the said light control layer differing between the said areas. Light control device. The light control sheet comprises a pair of alignment layers sandwiching the light control layer, the pair of transparent electrode layers sandwich the light control layer and the pair of alignment layers, at least one of the pair of alignment layers, The light control device according to claim 1 or 2, wherein the relationship between the magnitude of the voltage and the polarization direction of the liquid crystal molecules differs between the regions due to the different cured states of the alignment layer between the regions. A light control layer containing a polymer and liquid crystal molecules,
A pair of transparent electrode layers sandwiching the light control layer,
At least one of the thickness of the light control layer, the thickness of the transparent electrode layer, and the density of the polymer is different between regions, so that the magnitude of the voltage applied between the transparent electrode layers and the polarization of the liquid crystal molecules can be increased. A light control sheet that has a plurality of areas that have different relationships with directions. A light control layer containing a polymer and liquid crystal molecules,
A pair of alignment layers sandwiching the light control layer,
A pair of transparent electrode layers sandwiching the light control layer and the pair of alignment layers,
Since the thickness of the alignment layer and at least one of the cured states of the alignment layer are different between regions, a plurality of different relations between the magnitude of the voltage applied between the transparent electrode layers and the polarization direction of the liquid crystal molecules are obtained. Light control sheet with areas.