JP7133142B2 - Light control unit, light control component - Google Patents

Description

The present invention relates to a light control unit and a light control member having the light control unit.

2. Description of the Related Art Conventionally, a light control member capable of controlling light transmittance is known, for example, as described in Patent Literatures 1 and 2. As a method for adjusting the light transmittance of the light control member, a method using liquid crystal as shown in Patent Documents 1 and 2 is known. A light control member that uses liquid crystal can be configured simply and can ensure a very high light shielding performance.

In such a light modulating member, the liquid crystal is arranged between two alignment films. Each alignment film is laminated to a transparent substrate. The thickness of the liquid crystal layer can be maintained at a desired thickness by arranging a spacer of a predetermined size between the transparent substrates. As spacers, spherical bead spacers are often used from the viewpoint of ease of handling.

Japanese Patent No. 6213653 JP 2018-17775 A

From the viewpoint of assembly efficiency, it has been studied to fix bead spacers to the alignment films of the respective substrates in advance before assembling the pair of substrates. By the way, the bead spacers fixed to each alignment film may be arranged at the same position of the light control member in plan view. That is, there is a possibility that the bead spacers may overlap in plan view. If the bead spacers overlap, the liquid crystal layer becomes thick at that portion. That is, the thickness of the liquid crystal layer becomes thick locally. If the liquid crystal layer is locally thick, there is a possibility that local differences in optical characteristics will occur at that portion, deteriorating the field of view through the light modulating member.

The present invention has been made in consideration of the above points, and an object of the present invention is to avoid local thickening of the liquid crystal layer.

The light control unit of the present invention is
a first laminate having a first resin base material and a first alignment film laminated on the first resin base material;
a second resin substrate and a second alignment film laminated on the second resin substrate, wherein the first alignment film and the second alignment film are arranged so as to face each other , a second laminate, and
Liquid crystal molecules arranged between the first laminate and the second laminate, the orientation of which is controlled by applying a voltage to electrodes provided on at least one of the first laminate and the second laminate. a liquid crystal layer comprising
a plurality of bead spacers arranged between the first laminate and the second laminate;
The bead spacers include first bead spacers fixed to the first alignment film, second bead spacers fixed to the second alignment film, and both the first alignment film and the second alignment film. Including free bead spacers and not.

In the light control unit of the present invention, the ratio of the number of free bead spacers to the number of bead spacers may be 0.1% or more and 5.0% or less.

In the light control unit of the present invention,
the first alignment film includes a plurality of first protrusions protruding toward the liquid crystal layer;
at least a portion of the first protrusion at least partially surrounds the first bead spacer to hold the first bead spacer;
the second alignment film includes a plurality of second protrusions protruding toward the liquid crystal layer;
at least a portion of the second protrusion at least partially surrounds the second bead spacer to hold the second bead spacer;
At least one of the protrusion height of the first protrusion holding the first bead spacer and the protrusion height of the second protrusion holding the second bead spacer is 0.2 μm or more and less than 0.5 μm. may

In the light control unit of the present invention,
the first alignment film includes a plurality of first protrusions protruding toward the liquid crystal layer;
at least a portion of the first protrusion at least partially surrounds the first bead spacer to hold the first bead spacer;
the second alignment film includes a plurality of second protrusions protruding toward the liquid crystal layer;
at least a portion of the second protrusion at least partially surrounds the second bead spacer to hold the second bead spacer;
The projection height of the first projections other than the first projections holding the first bead spacers and the projection height of the second projections other than the second projections holding the second bead spacers At least one may be 0.2 μm or more and less than 0.5 μm.

In the light control unit of the present invention, the ratio of the projection height of the first projection holding the first bead spacer and the second projection holding the second bead spacer to the diameter [μm] of the bead spacer At least one of the projection height [μm] ratios of the portions may be 2.2% or more and less than 5.5%.

In the light control unit of the present invention, at least one of the thickness of the first alignment film and the thickness of the second alignment film may be 60 nm or more and 150 nm or less.

The light modulating member of the present invention is
a pair of substrates;
any one of the light control units described above disposed between the pair of substrates.

According to the present invention, local thickening of the liquid crystal layer can be avoided.

FIG. 1 is a perspective view schematically showing an automobile as an example of a mobile body provided with a light control member. FIG. 2 is a plan view showing the light modulating member from the direction normal to its plate surface. 3 is a cross-sectional view of the light control member taken along line III-III in FIG. 2. FIG. FIG. 4 is a plan view showing an enlarged part of the light control member. FIG. 5 is a diagram for explaining an example of a method for manufacturing a light control member. FIG. 6 is a diagram for explaining an example of a method for manufacturing a light control member. FIG. 7 is a diagram for explaining an example of a method for manufacturing a light control member. FIG. 8 is a diagram for explaining an example of a method for manufacturing a light control member. FIG. 9 is a diagram for explaining an example of a method for manufacturing a light control member.

An embodiment will be described below with reference to the drawings. In the drawings attached to this specification, for the convenience of illustration and ease of understanding, the scale and the ratio of vertical and horizontal dimensions are changed and exaggerated from those of the real thing.

In this specification, the terms "layer", "sheet" and "film" are not to be distinguished from each other based only on the difference in designation. For example, the term "layer" is a concept that includes members that can be called sheets or films.

In addition, "plate surface (sheet surface, film surface)" refers to the target plate-shaped member (sheet-shaped member) when viewed from the whole and perspective. member, film-like member).

Furthermore, the terms used herein to specify shapes and geometric conditions and their degrees, such as "parallel", "perpendicular", "identical", length and angle values, etc., are not strictly defined. It shall be interpreted to include the extent to which similar functions can be expected without being bound by the meaning.

FIG. 1 is a diagram schematically showing an automobile as an example of a mobile body provided with a light control member. FIG. 2 is a diagram of the light control member viewed from the normal direction of the plate surface thereof. 3 is a diagram showing a cross section of the light control member along line III-III in FIG. 2. FIG. FIG. 4 is a plan view showing an enlarged part of the light control member.

As shown in FIG. 1, an automobile 1 as an example of a moving body has window glass such as a sunroof, a rear window, and side windows. Here, an example in which the sunroof 5 is composed of the light control member 10 is exemplified. The automobile 1 also has a power source such as a battery (not shown). The light modulating member 10 can change the visible light transmittance by applying a voltage. For example, the light modulating member 10 can change the visible light transmittance between 70% and 1%. By appropriately adjusting the visible light transmittance of the light control member 10, an appropriate amount of external light such as sunlight can be transmitted. In addition, the light control member 10 can also block external light.

Here, the visible light transmittance is measured using a spectrophotometer ("UV-3100PC" manufactured by Shimadzu Corporation, compliant with JIS K 0115) within a range of measurement wavelengths of 380 nm to 780 nm. is specified as the mean value of the transmittance at

FIG. 2 shows the light modulating member 10 from the direction normal to its plate surface. 3 shows a cross-sectional view corresponding to line III-III of the light control member 10 of FIG. In the example shown in FIGS. 2 and 3, the light control member 10 is arranged between a first substrate 11 and a second substrate 12, which are a pair of substrates, and between the first substrate 11 and the second substrate 12. It has a light control unit 20, a first bonding layer 13 that bonds the first substrate 11 and the light control unit 20, and a second bonding layer 14 that bonds the second substrate 12 and the light control unit 20. there is Further, the light control member 10 has a wiring 15 for connecting with an external power supply. A voltage can be applied from a power supply to the light control member 10 via the wiring 15 . As shown in FIG. 2, the light control member 10 has a flat rectangular shape in plan view, but the light control member 10 may be curved. The dimming member 10 can have any suitable shape and size depending on the application.

Each component of the light control member 10 will be described below.

First, the first substrate 11 and the second substrate 12 are described. When the first substrate 11 and the second substrate 12 are used for the sunroof 5 of the automobile 1 as in the example shown in FIG. It is preferable to use a material having a high visible light transmittance, for example, a material having a visible light transmittance of 90% or more. Examples of materials for the first substrate 11 and the second substrate 12 include inorganic glass such as soda lime glass and soda lime glass, and resin glass such as polycarbonate and acrylic. When inorganic glass is used for the first substrate 11 and the second substrate 12, the light control member 10 having excellent heat resistance and scratch resistance can be obtained. When resin glass is used for the first substrate 11 and the second substrate 12, the light control member 10 can be made lightweight.

Moreover, it is preferable that the first substrate 11 and the second substrate 12 have a thickness of 1 mm or more and 5 mm or less. With such a thickness, the first substrate 11 and the second substrate 12 having excellent strength and optical properties can be obtained. The first substrate 11 and the second substrate 12 may be made of the same material and identically, or may be different from each other in at least one of the material and the configuration.

Next, the first bonding layer 13 and the second bonding layer 14 will be described. A first bonding layer 13 is disposed between the first substrate 11 and the light control unit 20 to bond the first substrate 11 and the light control unit 20 to each other. A second bonding layer 14 is disposed between the second substrate 12 and the light control unit 20 to bond the second substrate 12 and the light control unit 20 to each other.

As the first bonding layer 13 and the second bonding layer 14, it is possible to use layers made of materials having various adhesiveness or tackiness. Moreover, it is preferable that the first bonding layer 13 and the second bonding layer 14 have a high visible light transmittance. As a typical bonding layer, a layer made of polyvinyl butyral (PVB) can be exemplified. Alternatively, the joining layer may be a layer made of EVA (ethylene-vinyl acetate copolymer), COP (cycloolefin polymer), or the like. The thicknesses of the first bonding layer 13 and the second bonding layer 14 are preferably 0.15 mm or more and 1.5 mm or less. The first bonding layer 13 and the second bonding layer 14 may be configured identically with the same material, or may be different from each other in at least one of the material and the configuration.

It should be noted that the light control member 10 is not limited to the illustrated example, and may be provided with other functional layers that are expected to exhibit specific functions. Also, one functional layer may exhibit two or more functions. At least one of the first laminate 30 and the second laminate 40 of the light control unit 20, which will be described later, may be provided with some function. Examples of functions that can be imparted to the light control member 10 include an antireflection (AR) function, a scratch-resistant hard coat (HC) function, an infrared shielding (reflection) function, an ultraviolet shielding (reflection) function, and an anti-reflection function. A dirt function etc. can be illustrated.

Next, the dimming unit 20 will be explained. The light control unit 20 is formed in a flexible film shape. The light control unit 20 can change the visible light transmittance by applying a voltage. That is, the light control unit 20 provides the light control member 10 with a light control function. The light control unit 20 includes a first laminate 30 and a second laminate 40, a liquid crystal layer 25 disposed between the first laminate 30 and the second laminate 40, and a first laminate 30 and a second laminate. and a bead spacer 50 positioned between the bodies 40 . Further, the light control unit 20 has a sealing material 27 surrounding the liquid crystal layer 25 between the first laminate 30 and the second laminate 40 .

The first laminate 30 includes a first resin substrate 31 , a first alignment film 33 laminated on the first resin substrate 31 , and disposed between the first resin substrate 31 and the first alignment film 33 . and a first electrode 37 . Similarly, the second laminate 40 includes a second resin substrate 41 , a second alignment film 43 laminated on the second resin substrate 41 , and between the second resin substrate 41 and the second alignment film 43 . and a second electrode 47 disposed thereon. The first laminate 30 and the second laminate 40 are arranged such that the first alignment film 33 and the second alignment film 43 of the second laminate 40 face each other.

The first resin base material 31 is a member for appropriately supporting the first alignment film 33 and the first electrode 37 . Similarly, the second resin base material 41 is a member for appropriately supporting the second alignment film 43 and the second electrode 47 . Materials for the first resin base material 31 and the second resin base material 41 preferably have flexibility and high visible light transmittance. Examples of the first resin base material 31 and the second resin base material 41 include acetylcellulose resins such as triacetylcellulose (TAC), polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), Polyolefin resins such as polyethylene (PE), polypropylene (PP), polystyrene, polymethylpentene, and EVA, vinyl resins such as polyvinyl chloride and polyvinylidene chloride, acrylic resins, polyurethane resins, polysulfone (PEF), poly Examples of resins include ether sulfone (PES), polycarbonate (PC), polysulfone, polyether (PE), polyether ketone (PEK), (meth)acrylonitrile, cycloolefin polymer (COP), cycloolefin copolymer, etc. Resins such as polycarbonate, cycloolefin polymer, and polyethylene terephthalate are particularly preferred. The visible light transmittance of the first resin base material 31 and the second resin base material 41 is preferably 90% or more. Moreover, in the case of polyethylene terephthalate, for example, the first resin base material 31 and the second resin base material 41 preferably have a thickness of 30 μm or more and 250 μm or less. With such a thickness, the first resin base material 31 and the second resin base material 41 having excellent strength and optical properties can be obtained. The first resin base material 31 and the second resin base material 41 may be made of the same material in the same manner, or may be different from each other in at least one of the material and the construction.

The first alignment film 33 and the second alignment film 43 are layers adjacent to the liquid crystal layer 25 and regulate the alignment of liquid crystal molecules in the liquid crystal layer 25 . The method of manufacturing the first alignment film 33 and the second alignment film 43 is not particularly limited. The first alignment film 33 and the second alignment film 43 having liquid crystal alignment ability can be produced by any method. For example, the first alignment film 33 and the second alignment film 43 may be produced by performing a rubbing treatment on a resin layer such as polyimide, or a polymer film may be irradiated with linearly polarized ultraviolet rays to increase the polarization direction. The first alignment film 33 and the second alignment film 43 may be produced based on a photo-alignment method in which molecular chains are selectively reacted. Instead of the first alignment film 33 and the second alignment film 43 formed by such a rubbing process, the first alignment film 33 and the second alignment film 43 are formed by forming a fine line-shaped concave-convex shape formed by a rubbing process by a molding process. 43 may be made. Further, when the GH method is used for the liquid crystal layer 25, which will be described later, the rubbing treatment may not be performed.

The thickness T of the first alignment film 33 is, for example, 60 nm or more and 150 nm or less. Similarly, the thickness T of the second alignment film 43 is, for example, 60 nm or more and 150 nm or less. It should be noted that the thickness of the first alignment film 33 and the thickness of the second alignment film 43 are each the thickness of the first alignment film 33 at the number of measurement positions (for example, 30 points) that can reflect the overall tendency. It can be specified as an average thickness and an average thickness of the second alignment film 43 . In particular, the thickness of the first alignment film 33 and the thickness of the second alignment film 43, which are produced by the manufacturing method described later and have the specific configuration described here, are specified by the average value of the measured values of 30 points. can do. The thicknesses of the first alignment film 33 and the second alignment film 43 are the thicknesses of the portions excluding the first protrusions 35 and the second protrusions 45 described later, specifically the thicknesses of the first protrusions 35 and the second protrusions 45 . Measured at points on the part spaced apart by 6 μm or more. The thicknesses of the first alignment film 33 and the second alignment film 43 can be measured, for example, from images of cross sections of the first laminate 30 and the second laminate 40 captured by a scanning electron microscope (SEM).

As shown in FIG. 3, the first alignment film 33 includes a plurality of first projections 35 projecting toward the liquid crystal layer 25 . As shown in FIG. 3, at least a portion of the first protrusion 35 at least partially surrounds the first bead spacer 51, which is part of the bead spacer 50, to hold the first bead spacer 51. . The first protrusions 35 hold the first bead spacers 51 so that the first bead spacers 51 are fixed to the first alignment film 33 . Of the first protrusions 35, the other first protrusions 35 that do not hold the first bead spacers 51 have, as shown in FIG. extended. In the example shown in FIG. 4, the first protrusions 35 that do not hold the first bead spacers 51 extend over the entire circumferential pattern in plan view.

Similarly, the second alignment film 43 includes a plurality of second projections 45 projecting toward the liquid crystal layer 25 . As shown in FIG. 3, at least a portion of the second convex portion 45 at least partially surrounds the second bead spacer 52, which is part of the bead spacer 50, to hold the second bead spacer 52. . The second protrusions 45 hold the second bead spacers 52 so that the second bead spacers 52 are fixed to the second alignment film 43 . Some of the second protrusions 45 that do not hold the second bead spacers 52 linearly extend through at least a portion of the circumferential pattern in plan view.

The protrusion height Ha of the first convex portion 35 that holds the first bead spacer 51 is 0.2 μm or more and less than 0.5 μm. Similarly, the protrusion height Ha of the second protrusion 45 that holds the second bead spacer 52 is 0.2 μm or more and less than 0.5 μm. Moreover, the protrusion height Hb of the first protrusions 35 that do not hold the first bead spacers 51, that is, the protrusion height Hb of the first protrusions 35 other than the first protrusions 35 that hold the first bead spacers 51, is 0.5. It is 2 μm or more and less than 0.5 μm. Similarly, the protrusion height Hb of the second protrusions 45 that do not hold the second bead spacers 52, that is, the second protrusions 45 other than the second protrusions 45 that hold the second bead spacers 52, is 0.2 μm or more. .5 μm or less. Here, the protrusion heights of the first protrusions 35 and the second protrusions 45 are the number (for example, 30) of the first protrusions 35 and the second protrusions that are considered to reflect the overall tendency. It can be specified as the average of 45 protrusion heights. The protrusion heights of the first protrusions 35 and the second protrusions 45 are defined by the protrusion heights (thicknesses) at the highest points of the first protrusions 35 and the second protrusions 45 . In particular, the protrusion height of the first protrusion 35 and the protrusion height of the second protrusion 45, which are manufactured by the manufacturing method described later and have the specific configuration described here, are determined by the average value of 30 measurement values. , can be specified. The protrusion height of the first protrusion 35 and the protrusion heights Ha and Hb of the second protrusion 45 can be measured by, for example, a scanning white light interferometer (“Zygo” manufactured by Zygo Corporation).

For the first electrode 37 and the second electrode 47, for example, tin oxide-based, indium oxide-based, or zinc oxide-based transparent metal thin films can be applied. Examples of tin oxide (SnO ₂ )-based materials include Nesa (tin oxide SnO ₂ ), ATO (Antimony Tin Oxide), and fluorine-doped tin oxide. Examples of indium oxide (In ₂ O ₃ )-based materials include indium oxide, ITO (Indium Tin Oxide), and IZO (Indium Zinc Oxide). Examples of zinc oxide (ZnO) systems include zinc oxide, AZO (aluminum-doped zinc oxide), and gallium-doped zinc oxide. In this embodiment, the first electrode 37 and the second electrode 47 are formed as transparent electrodes using ITO. The manner in which the first electrode 37 and the second electrode 47 are arranged is not particularly limited, and the electrodes may be arranged only at predetermined locations by patterning, or the electrodes may be arranged in a solid pattern. An electric field acting on the liquid crystal layer 25 arranged between the first electrode 37 and the second electrode 47 is formed in accordance with the voltage applied to the first electrode 37 and the second electrode 47 , and the voltage included in the liquid crystal layer 25 is generated. The orientation of the liquid crystal molecules is controlled. The visible light transmittance of the first electrode 37 and the second electrode 47 is preferably 50% or more, for example. The thickness of the first electrode 37 and the second electrode 47 is, for example, 50 μm or more and 200 μm or less.

For the liquid crystal layer 25, for example, a VA (Vertical Alignment) method, a TN (Twisted Nematic) method, an IPS (In Plane Switching) method, an FFS (Fringe Field Switching) method, or a GH (Guest Host) method can be used. In this embodiment, as an example, the liquid crystal layer 25 uses the GH system. When using the GH system, the liquid crystal layer 25 contains liquid crystal molecules and a dichroic dye composition.

By applying a voltage to at least one of the electrodes 37 and 47 via the wiring 15, an electric field is formed, and the orientation of the liquid crystal molecules in the liquid crystal layer 25 can be changed by the action of the electric field. The orientation of the liquid crystal molecules can change the polarization direction of light passing through the liquid crystal layer 25 . For example, when a GH liquid crystal is used, when no voltage is applied, the liquid crystal molecules and the dichroic dye composition are arranged perpendicular to the first alignment film 33 and the second alignment film 43, and light is transmitted. do. As the voltage is applied, the liquid crystal molecules and the dichroic dye composition become horizontal to the first alignment film 33 and the second alignment film 43, and the visible light transmittance decreases. When a voltage is sufficiently applied, the liquid crystal molecules and the dichroic dye composition are aligned horizontally with respect to the first alignment film 33 and the second alignment film 43, blocking light. In this way, the light control unit 20 can change the orientation of the liquid crystal molecules of the liquid crystal layer 25 by controlling the voltage application, and adjust the visible light transmittance.

The thickness of the liquid crystal layer 25 is, for example, 6 μm or more and 9 μm or less. The thickness of the liquid crystal layer 25 is equal to the size of the space between the first stack 30 and the second stack 40 secured by the bead spacers 50 . Here, the thickness of the liquid crystal layer 25 can be specified as the average thickness of the liquid crystal layer 25 at the number of measurement positions (for example, 30 points) that can reflect the overall trend. In particular, the thickness of the liquid crystal layer 25, which is manufactured by the manufacturing method described later and has the specific configuration described here, can be specified by the average value of 30 measured values. Also, the thickness of the liquid crystal layer 25 is substantially constant throughout the light control unit 20 . The fact that the thickness of the liquid crystal layer 25 is substantially constant means, for example, that the difference between the maximum and minimum diameters of the thirty bead spacers 50 is 0.1 μm or less.

The sealing material 27 surrounds the liquid crystal layer 25 in a circumferential shape, as shown in FIG. That is, the sealing material 27 partitions the liquid crystal layer 25 . Also, the sealing material 27 is provided between the first laminate 30 and the second laminate 40, as shown in FIG. The sealing material 27 serves to prevent the liquid crystal molecules forming the liquid crystal layer 25 from leaking from between the first laminate 30 and the second laminate 40, and also prevents the first laminate 30 and the second laminate 40 from leaking out. It plays a role of adhering to and fixing both to each other. The sealing material 27 can be made of, for example, a thermosetting resin such as an epoxy resin or an acrylic resin, an ultraviolet curable resin, or the like.

The bead spacer 50 is arranged between the first laminate 30 and the second laminate 40 to secure a space between the first laminate 30 and the second laminate 40 . A liquid crystal layer 25 is formed by filling this space with a liquid crystal material containing liquid crystal molecules. The liquid crystal layer 25 described above controls the amount of phase modulation of transmitted light, and therefore has a somewhat constant thickness between the first laminate 30 and the second laminate 40. is required. For this reason, the bead spacers 50 are preferably spherical. The diameter of the bead spacer 50 is, for example, 6 μm or more and 9 μm or less. Here, the diameter of the bead spacers 50 can be specified as the average of the diameters of a number (eg, 30) of bead spacers that can be considered to reflect the overall trend. Specifically, the diameter of the bead spacers 50 described herein can be specified as an average of thirty measurements.

Also, the ratio of the projection height [μm] of the first projection 35 holding the first bead spacer 51 to the diameter [μm] of the bead spacer 50 and the projection of the second projection 45 holding the second bead spacer 52 The height [μm] ratio is preferably 2.2% or more and less than 5.5%. As described above, the diameter [μm] of the bead spacers 50 can be specified as the average value of a sufficient number that can reflect the overall trend, and the protrusion height of the first protrusions 35 is also the overall A sufficient number of mean values can be identified that can be considered to reflect trends.

The diameter of the bead spacer 50 can be measured by, for example, dynamic light scattering method or laser diffraction method.

Further, the surface density of the bead spacers 50 in plan view is, for example, 30 [pieces/mm ² ] or more and 160 [pieces/mm ² ] or less. When the bead spacers are uniformly distributed over the entire light control unit 20, the surface density of the bead spacers can be obtained by counting the number of the bead spacers 50 included in an area (for example, 1 mm square) of the light control unit 20. can be specified. In particular, the surface density of the bead spacers 50 in the light control unit 20 manufactured by the manufacturing method described later can be defined by the number of the bead spacers 50 included in 1 mm square. When the bead spacers 50 are agglomerated, that is, when a plurality of bead spacers 50 form a clump, the agglomerate of the bead spacers 50, that is, the clump of the bead spacers 50, is counted as one bead spacer 50. FIG.

A plurality of bead spacers 50 are discretely arranged between the first laminate 30 and the second laminate 40 . The bead spacer 50 is formed of an inorganic material such as silica, an organic material, or a core-shell structure combining these materials.

The bead spacers 50 consist of a first bead spacer 51 fixed to the first alignment film 33, a second bead spacer 52 fixed to the second alignment film 43, or any of the first alignment film 33 and the second alignment film 43. and a free bead spacer 53 that is not attached to either. In other words, the number of bead spacers 50 arranged between the first laminate 30 and the second laminate 40 is equal to the number of the first bead spacers 51 fixed to the first alignment film 33 and the number of the second alignment film 43 . It is more than the sum of the number of the second bead spacers 52 fixed to the base. The first bead spacer 51 is fixed to the first alignment film 33 by being at least partially surrounded and held by the first protrusions 35 . Similarly, the second bead spacer 52 is fixed to the second alignment film 43 by being at least partially surrounded and held by the second convex portion 45 .

A first bead spacer 51 is fixed to the first alignment film 33 and a second bead spacer 52 is fixed to the second alignment film 43 . That is, in the liquid crystal layer 25 , the movement of the first bead spacers 51 with respect to the first alignment film 33 is restricted, and the movement of the second bead spacers 52 with respect to the second alignment film 43 is restricted. Therefore, it is possible to prevent deterioration of the field of view through the light control member 10 due to the generation of air bubbles in the liquid crystal layer 25 due to the movement of the first bead spacers 51 and the second bead spacers 52 . On the other hand, the free bead spacers 53 are movable in the liquid crystal layer 25 . That is, the free bead spacers 53 are movable with respect to the first bead spacers 51 and the second bead spacers 52 . In other words, the free bead spacer 53 is movable with respect to the first alignment film 33 and the second alignment film 43 .

The ratio of the number of free bead spacers 53 to the total number of bead spacers 50 is preferably 0.1% or more and 5.0% or less. The free bead spacers 53 are generated by dropping off the bead spacers 50 fixed to the first alignment film 33 or the second alignment film 43 in the manufacturing process of the light control unit 20, which will be described later.

The ratio of the number of free bead spacers 53 to the total number of bead spacers 50 is, for example, the number of bead spacers 50 and free bead spacers 50 in a partial area (for example, 1 mm square) of the light control unit 20 that can reflect the overall trend. It can be defined by counting the number of bead spacers 53 . In particular, the ratio of the free bead spacers 53 to the total number of bead spacers 50 in the light control unit 20 manufactured by the manufacturing method described later is defined by the number of the bead spacers 50 and the number of the free bead spacers 53 included in 1 mm square. can be done.

The number of free bead spacers 53 is equal to the number of traces of the bead spacers 50 falling off from the first alignment film 33 or the second alignment film 43 . The drop traces of the bead spacers 50 are the first protrusions 35 or the second protrusions 45 left by the drop of the bead spacers 50 , and the first protrusions 35 and the second protrusions 35 that do not hold the first bead spacers 51 . It means the second convex portion 45 that does not hold the two-bead spacer 52 . For example, as shown in FIG. 4 , the first protrusions 35 linearly extending through at least a portion of the circumferential pattern in plan view are traces of the bead spacers 50 . It should be noted that the first convex portion 35 as a dropout trace of the bead spacer 50 shown in FIG. 4 extends along the entire length of the circular pattern.

In addition to the bead spacers 50 , a columnar spacer or the like may be arranged between the first laminate 30 and the second laminate 40 . The pillar-shaped spacers can be formed at desired positions using a photolithographic technique or screen printing.

Next, an example of a method for manufacturing the light control member 10 and the light control unit 20 will be described with reference to FIGS. 5 to 9. FIG.

First, as shown in FIG. 5, a second plate member 40a in which the bead spacers 50 are uniformly dispersed is prepared. The second plate member 40a is a member that forms the second laminate 40 by being trimmed. The second plate member 40a in which the bead spacers 50 are uniformly dispersed can be produced, for example, as follows. First, the second electrode 47 is formed on the second resin base material 41 by sputtering or the like. Bead spacers 50 are then sprinkled over the second electrode 47 . After that, a composition that will form the second alignment film 43 is applied onto the second resin substrate 41 . At this time, the viscosity of the composition that forms the second alignment film 43 and the surface tension between the bead spacer 50 and the composition that forms the second alignment film 43 form the second protrusions 45 . A second skirt portion 45 a is formed between the bead spacer 50 and the second resin base material 41 . Alternatively, the spacer beads 50 may be dispersed in the composition forming the second alignment film 43 , and the composition containing the spacer beads 50 may be applied onto the second resin substrate 41 . After that, the composition is volatilized and dried in a drying oven. Next, the second alignment film 43 is formed by imparting an alignment regulating force to the coating film by rubbing, optical alignment, or the like. As described above, the second plate member 40a with the bead spacers 50 scattered thereon is obtained.

By drying the composition that forms the second alignment film 43 , the second skirt portion 45 a hardens and becomes the second convex portion 45 . The second protrusion 45 holds the bead spacer 50 . The protrusion height of the second protrusions 45 is sufficiently high, 0.2 μm or more, so that the second protrusions 45 can reliably hold the bead spacers 50 . The ratio of the projection height [μm] of the second convex portion 45 holding the second bead spacer 52 to the diameter [μm] of the bead spacer 50 is 2.2% or more. The bead spacers 50 held by the second protrusions 45 become the second bead spacers 52 fixed to the second alignment film 43 .

By adjusting the amount of polyimide or the like contained in the composition that forms the second alignment film 43, the viscosity of the composition can be adjusted. Thereby, the height of the second skirt portion 45a can be adjusted. That is, the height of the second convex portion 45 formed from the second skirt portion 45a can be adjusted.

Next, as shown in FIG. 6, a sealing material 27a is applied circumferentially. The sealing material 27a is a viscous liquid material having adhesiveness or cohesiveness. The sealing material 27a forms the sealing material 27 by hardening. Thereafter, as shown in FIG. 7, a liquid crystal material 25a containing liquid crystal molecules is supplied to the area on the second plate member 40a surrounded by the sealing material 27a.

Next, as shown in FIG. 8, under reduced pressure, the first plate member 30a in which the bead spacers 50 are uniformly dispersed is stacked on the second plate member 40a. When laminating the first plate member 30a on the second plate member 40a, a roller or the like may be used to squeeze. The first plate member 30a is a member that forms the first laminate 30 by being trimmed, and can be produced, for example, in the same process as the second plate member 40a. That is, the first plate member 30a is formed by first forming the first electrode 37 on the first resin base material 31, scattering the bead spacers 50 on the first electrode 37, and then forming the first alignment film 33. The first alignment film 33 is produced by applying a composition that becomes similar to the first resin substrate 31, volatilizing it in a drying oven, and then imparting an orientation regulating force to the coating film. obtain. In the same manner as the second plate member 40a already described, the spacer beads 50 are dispersed in the composition that forms the first alignment film 33, and the composition containing the spacer beads 50 is applied to the first resin substrate 31. You may make it apply|coat to. A first protrusion 35 is formed on the first alignment film 33 , and the first protrusion 35 holds the bead spacer 50 . The bead spacers 50 held by the first projections 35 become the first bead spacers 51 fixed to the first alignment film 33 .

When the first plate member 30a is stacked on the second plate member 40a, if the first bead spacers 51 and the second bead spacers 52 overlap each other, the first bead spacers 51 and the second bead spacers 52 may is under pressure. By this pressure, at least one of the first bead spacer 51 and the second bead spacer 52 which are positioned overlapping each other is peeled off from the corresponding alignment films 33 and 43 and dropped. The degree of fixation of the bead spacers to the alignment film is adjusted so that the bead spacers fall off when the first bead spacers 51 and the second bead spacers 52 overlap each other. Specifically, the protrusion height of the first protrusion 35 and the protrusion height of the second protrusion 45 are sufficiently low as less than 0.5 μm. Also, the ratio of the projection height [μm] of the first protrusion 35 holding the first bead spacer 51 to the diameter [μm] of the bead spacer 50 and the second bead spacer 52 to the diameter [μm] of the bead spacer 50 are shown. The ratio of the protrusion height [μm] of the second protrusion 45 to the second protrusion 45 is less than 5.5%.

The dropped bead spacer 50 is not held by either the first protrusion 35 or the second protrusion 45 . That is, the dropped bead spacers 50 become free bead spacers 53 that are not fixed to either the first alignment film 33 or the second alignment film 43 .

The first projection 35 or the second projection 45 spaced apart from the bead spacer 50 is left as a trace of the drop of the bead spacer 50 . As shown in FIG. 4, the first convex portion 35 or the second convex portion 45 as a trace of the bead spacer 50 falling off is at least part of the circular pattern having a shape that held the bead spacer 50 in plan view. It has a shape that extends linearly.

The liquid crystal material 25 a filled in the space secured by the bead spacers 50 between the first plate member 30 a and the second plate member 40 a forms the liquid crystal layer 25 . After that, the sealing material 27a is deformed and hardened by ultraviolet irradiation and heat treatment to become the sealing material 27, which joins the first plate member 30a and the second plate member 40a. Through the above steps, a laminate including the first plate member 30a, the second plate member 40a, and the liquid crystal layer 25 arranged between the first plate member 30a and the second plate member 40a is prepared.

Next, the first plate material 30a and the second plate material 40a are partly cut to remove the outer peripheries of the first plate material 30a and the second plate material 40a, which are excess regions, that is, the first plate material 30a and the second plate material 40a are trimmed. do. This cutting is preferably performed at least partially on the sealing material 27 . The trimming of the first plate material 30a and the second plate material 40a can be performed by using tools such as punching blades and cutters. In this manner, the first plate member 30a becomes the first laminate 30, and the second plate member 40a becomes the second laminate 40, whereby the light control unit 20 is obtained.

Finally, as shown in FIG. 9, the first bonding layer 13 and the first substrate 11 are laminated on the first laminate 30 side of the light control unit 20 to bond the light control unit 20 and the first substrate 11. do. Similarly, the second bonding layer 14 and the second substrate 12 are laminated on the side of the second laminate 40 of the light control unit 20 to bond the light control unit 20 and the second substrate 12 together. Thereby, the light control member 10 shown in FIG. 3 is manufactured.

By the way, in the conventional light control member, the first bead spacers fixed to the first alignment film of the first laminate partly overlap with the second bead spacers fixed to the second alignment film of the second laminate partly. there is a possibility. When the first bead spacer and the second bead spacer partially overlap, the space between the first stack and the second stack at the overlapping position is the same as the first stack and the second stack at the non-overlapping position. It becomes larger than the space between the laminates. Therefore, the thickness of the liquid crystal layer in the space where the first bead spacer and the second bead spacer overlap is equal to the thickness of the liquid crystal layer in the space where the first bead spacer and the second bead spacer do not overlap. It becomes thicker than thicker. If a part of the liquid crystal layer is locally thickened, it causes a local difference in optical properties. That is, in the conventional light control member, overlapping of the bead spacers causes an optical singular point, which may deteriorate the field of view through the light control member.

In particular, as in the present embodiment, when the GH method is used for the liquid crystal layer, if the liquid crystal layer is thick in a part of the light control member, the thickness is proportional to the thickness in the thick part of the light control member. As a result, the number of dichroic dye compositions increases. That is, a darker color can be observed in a portion where the liquid crystal layer is thicker. For this reason, in the field of view through the light control member, color unevenness is likely to be visually recognized, which may further deteriorate the field of view.

On the other hand, in the present embodiment, when pressure is applied in the manufacturing process of the light control unit 20, the first bead spacers 51 are separated from the first alignment film 33, or the second bead spacers 52 are separated from the second alignment film 43. The fixing strength of the first bead spacers 51 to the first alignment film 33 and the fixing strength of the second bead spacers 52 to the second alignment film 43 are adjusted so that they fall off. Specifically, by appropriately designing the thickness of the first alignment film 33 and the second alignment film 43 and the protrusion height of the first protrusion 35 and the second protrusion 45, the alignment films of the bead spacers 51 and 52 are Adhesion strength to 33 and 43 is adjusted. Therefore, when pressure is applied, the first bead spacers 51 and the second bead spacers 52 are easily removed from the first alignment film 33 and the second alignment film 43, respectively.

In the manufacturing process of the light control unit 20, when the first plate member 30a and the second plate member 40a are laminated, if the first bead spacer 51 and the second bead spacer 52 are positioned so as to overlap each other, the first bead Pressure is applied to spacer 51 and second bead spacer 52 . By this pressure, at least one of the overlapping first bead spacers 51 and second bead spacers 52 can be removed from the fixation by the first alignment film 33 or the fixation by the second alignment film 43 . The dropped first bead spacers 51 or second bead spacers 52 become free bead spacers 53 that are not fixed to either the first alignment film 33 or the second alignment film 43 .

In the light control unit 20 of the present embodiment, the bead spacers 50 include the first bead spacers 51 fixed to the first alignment film 33 and the second bead spacers 52 fixed to the second alignment film 43. A free bead spacer 53 is included. As described above, the free bead spacers 53 are formed by at least one of the first bead spacers 51 and the second bead spacers 52 that may be positioned overlapping in the thickness direction of the light control unit 20 in the manufacturing process of the light control unit 20. Fall off and be created. Therefore, in the light control unit 20 , the first bead spacer 51 and the second bead spacer 52 are less likely to be positioned while overlapping each other in the thickness direction of the light control unit 20 . As a result, local increase in the thickness of the liquid crystal layer 25 due to the overlapping positions of the first bead spacers 51 and the second bead spacers 52 can be suppressed. That is, the thickness of the liquid crystal layer 25 can be made substantially constant. Specifically, the difference between the maximum and minimum diameters of the bead spacers 50 can be 0.1 μm or less. Therefore, the liquid crystal layer 25 is less likely to be thickened locally, and deterioration of visibility through the light control member 10 having the light control unit 20 can be prevented.

Further, in the light control unit 20 of the present embodiment, the ratio of the number of free bead spacers 53 to the total number of bead spacers 50 is 0.1% or more and 5.0% or less. That is, the number of bead spacers 50 that are not fixed to either the first alignment film 33 or the second alignment film 43 is sufficiently reduced. In other words, most of the bead spacers 50 are fixed to the first alignment film 33 or the second alignment film 43 . Therefore, it is possible to effectively prevent the movement of the bead spacers 50 from causing air bubbles or the like in the liquid crystal layer 25 and deteriorating the visibility through the light control member 10 .

Furthermore, in the light control unit 20 of the present embodiment, the projection height of the first convex portion 35 holding the first bead spacer 51 and the second convex portion 45 holding the second bead spacer 52 is 0.2 μm or more. It is less than 0.5 μm, the height of the projection of the first projections 35 other than the first projections 35 holding the first bead spacers 51 and the projection height of the second projections other than the second projections 45 holding the second bead spacers 52 The protrusion height of the portion 45 is 0.2 μm or more and less than 0.5 μm. In such a case, while the first convex portion 35 and the second convex portion 45 securely hold the first bead spacer 51 and the second bead spacer 52, the first convex portion 35 and the second convex portion 45 are displaced when pressure is applied. The first bead spacers 51 and the second bead spacers 52 can be easily removed from the grooves. Therefore, even if the first bead spacers 51 and the second bead spacers 52 overlap each other in the manufacturing process of the light control unit 20, the first bead spacers 51 or the second bead spacers 52 can be removed. . Since the thickness of the liquid crystal layer 25 can be kept substantially constant, it is possible to prevent deterioration of visibility through the light control member 10 due to local thickening of the liquid crystal layer 25 .

Also, the thickness of the first alignment film 33 and the second alignment film 43 is 60 nm or more and 150 nm or less. In such a case, the bead spacers 50 can be easily removed from the first alignment film 33 and the second alignment film 43 . Therefore, the bead spacers 50 are fixed to the first alignment film 33, the second bead spacers 52 to the second alignment film 43, and the first alignment film 33 and the second alignment film 43. It is easier to include free bead spacers 53 that are not attached. Therefore, the thickness of the liquid crystal layer 25 can be kept substantially constant, and deterioration of visibility through the light control member 10 due to local thickening of the liquid crystal layer 25 can be prevented.

Furthermore, the ratio of the projection height [μm] of the first projection 35 holding the first bead spacer 51 and the projection height [μm] of the second projection 45 holding the second bead spacer 52 to the diameter [μm] of the bead spacer 50 is It is 2.2% or more and 5.5% or less. In such a case, the first bead spacer 51 held by the first convex portion 35 and the second bead spacer 52 held by the second convex portion 45 are not pressed until pressure is applied in the manufacturing process of the light control unit 20. Not easy to fall off. Moreover, in the manufacturing process of the light control unit 20, it falls off due to the application of pressure. Therefore, when the first bead spacers 51 and the second bead spacers 52 overlap each other, the first bead spacers 51 and the second bead spacers 52 are easily removed, and the appropriate number of the first bead spacers 51 and the appropriate number of bead spacers 51 and 52 are removed. A second bead spacer 52 is held by the first protrusion 35 and the second protrusion 45 . Therefore, the thickness of the liquid crystal layer 25 can be kept substantially constant, and deterioration of visibility through the light control member 10 due to local thickening of the liquid crystal layer 25 can be prevented.

As described above, the light control unit 20 of the present embodiment includes the first laminate 30 having the first resin base material 31 and the first alignment film 33 laminated on the first resin base material 31, It has a second resin base material 41 and a second alignment film 43 laminated on the second resin base material 41, and is arranged such that the first alignment film 33 and the second alignment film 43 face each other. and electrodes 37 and 47 arranged between the first and second laminates 30 and 40 and provided on at least one of the first and second laminates 30 and 40 and a plurality of bead spacers 50 arranged between the first laminate 30 and the second laminate 40, and a bead spacer 50, a first bead spacer 51 fixed to the first alignment film 33, a second bead spacer 52 fixed to the second alignment film 43, and affixed to both the first alignment film 33 and the second alignment film 43; and free bead spacers 53 that are not free. The free bead spacers 53 of the light control unit 20 are formed by removing the first bead spacers 51 and the second bead spacers 52 that may have overlapped during the manufacturing process of the light control unit 20 . That is, in such a light control unit 20, the first bead spacers 51 and the second bead spacers 52 are less likely to overlap, and the thickness of the liquid crystal layer 25 can be made substantially constant. Therefore, the liquid crystal layer 25 is less likely to be thickened locally, and deterioration of visibility through the light control member 10 having the light control unit 20 can be suppressed.

Such a light control member 10 may be used not only for the sunroof of the automobile 1 as shown in FIG. 1, but also for the rear window and the side window. It may also be used for windows or doors of moving bodies other than automobiles, such as railway vehicles, aircraft, ships, and spaceships.

Furthermore, the light control member 10 can be used not only in moving objects, but also in places that separate indoors from outdoors, such as transparent parts of windows or doors of buildings, shops, houses, windows or doors of buildings, refrigerators, display boxes, and cupboards. It can also be used for transparent parts of windows or doors of storage or storage facilities such as.

In the embodiment described above, the light control member 10 is formed by placing the light control unit 20 between the first substrate 11 and the second substrate 12 . However, the light control member 10 may be formed by bonding the light control unit 20 to one substrate.

Moreover, in the above-described embodiment, the bead spacers 50 are uniformly dispersed in the alignment films 33 and 43 and manufactured. However, the bead spacers 50 may be unevenly distributed in the alignment films 33,43.

Furthermore, in the above-described embodiment, the protrusion height of the first protrusions 35 holding the first bead spacers 51 and the protrusion height of the second protrusions 45 holding the second bead spacers 52 are both 0.2 μm. The projection height of the first projections 35 other than the first projections 35 holding the first bead spacers 51 and the projection height of the second projections other than the second projections 45 holding the second bead spacers 52 are equal to or more than 0.5 μm and less than 0.5 μm. An example in which the protrusion heights of the protrusions 45 are both 0.2 μm or more and less than 0.5 μm is shown. However, at least one of the projection height of the first projections 35 holding the first bead spacers 51 and the projection height of the second projections 45 holding the second bead spacers 52 is between 0.2 μm and 0.5 μm. may be less than Also, the protrusion height of the first protrusions 35 other than the first protrusions 35 holding the first bead spacers 51 and the protrusion height of the second protrusions 45 other than the second protrusions 45 holding the second bead spacers 52 At least one of the thicknesses may be 0.2 μm or more and less than 0.5 μm. Even in this case, even if the first bead spacers 51 and the second bead spacers 52 overlap each other in the manufacturing process of the light control unit 20, the first bead spacers 51 or the second bead spacers 52 may be removed. It is possible to make the thickness of the liquid crystal layer 25 substantially constant.

In the above-described embodiment, the ratio of the projection height [μm] of the first projection 35 holding the first bead spacer 51 to the diameter [μm] of the bead spacer 50 and the second bead spacer 52 are held An example is shown in which the ratios of the protrusion heights [μm] of the second protrusions 45 are both 2.2% or more and 5.5% or less. However, the ratio of the projection height [μm] of the first projection 35 holding the first bead spacer 51 to the diameter [μm] of the bead spacer 50 and the projection of the second projection 45 holding the second bead spacer 52 At least one of the height [μm] ratios may be 2.2% or more and 5.5% or less. Even in this case, even if the first bead spacers 51 and the second bead spacers 52 overlap each other in the manufacturing process of the light control unit 20, the first bead spacers 51 or the second bead spacers 52 may be removed. It is possible to make the thickness of the liquid crystal layer 25 substantially constant.

Furthermore, in the embodiment described above, the thickness of the first alignment film 33 and the thickness of the second alignment film 43 are both 60 nm or more and 150 nm or less. However, at least one of the thickness of the first alignment film 33 and the thickness of the second alignment film 43 may be 60 nm or more and 150 nm or less. Even in this case, even if the first bead spacers 51 and the second bead spacers 52 overlap each other in the manufacturing process of the light control unit 20, the first bead spacers 51 or the second bead spacers 52 may be removed. It is possible to make the thickness of the liquid crystal layer 25 substantially constant.

EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

As examples and comparative examples, light control members having light control units with different projecting heights of the first and second protrusions and different thicknesses of the first alignment film 33 and the second alignment film were prepared. The above-described manufacturing method was adopted as the manufacturing method of the light control member having the light control unit, and it was common to the examples and the comparative examples. Elements other than the protrusion heights of the first protrusions and the second protrusions and the thicknesses of the first alignment film and the second alignment film are common to the example and the comparative example. In the light modulating members of Examples and Comparative Examples, the first resin base material and the second resin base material are made of a polycarbonate resin having a thickness of 100 μm, and the first alignment film and the second alignment film are made of a polyimide resin. A GH system is used for the liquid crystal layer. The bead spacer is made of acrylic resin with a diameter of 9.0 μm. The first substrate and the second substrate are made of polycarbonate resin with a thickness of 100 μm, and the first bonding layer and the second bonding layer are made of acrylic epoxy resin with a thickness of 20 μm.

The protrusion height of the first protrusion and the second protrusion in the example is 0.3 μm, and the thickness of the first alignment film and the second alignment film is 100 nm. Therefore, the ratio of the thickness of the first alignment film and the second alignment film to the diameter of the bead spacer in the example is 5%. On the other hand, the protrusion height of the first protrusion and the second protrusion in the comparative example is 0.7 μm, and the thickness of the first alignment film and the second alignment film is 200 nm. Therefore, the ratio of the thickness of the first alignment film and the second alignment film to the diameter of the bead spacer in the comparative example is 8%.

In the light control unit of the example, the protrusion heights of the first protrusions and the second protrusions are lower than those of the light control unit of the comparative example, and the thicknesses of the first alignment film and the second alignment film are thinner. ing. Therefore, in the light control unit of the example, the bead spacers are more likely to come off from the first protrusion and the second protrusion than in the light control unit of the comparative example. When actually confirmed using an optical microscope, the alignment film of the light control unit of the example was confirmed to have a circular convex portion that did not hold the bead spacer as a trace of falling off. On the other hand, in the light control unit of the comparative example, no circumferential first convex portion separated from the bead spacer was observed.

No color unevenness was observed in the field of view through the light control member having the light control unit of the example. This is because one of the bead spacers fell off at the position where the first bead spacer and the second bead spacer overlapped in the manufacturing process of the light control unit, and the thickness of the liquid crystal layer became substantially constant. it is conceivable that. On the other hand, color unevenness was observed in the field of view through the light control member having the light control unit of the comparative example. It is thought that this is because in the manufacturing process of the light control unit, one of the bead spacers did not drop off at the position where the first bead spacer and the second bead spacer overlapped, and the liquid crystal layer was locally thickened. be done.

1 automobile 5 sunroof 10 light control member 11 first substrate 12 second substrate 13 first bonding layer 14 second bonding layer 15 wiring 20 light control unit 25 liquid crystal layer 27 sealing material 30 first laminate 31 first resin base material 33 First alignment film 35 First protrusion 37 First electrode 40 Second laminate 41 Second resin substrate 43 Second alignment film 45 Second protrusion 47 Second electrode 50 Bead spacer 51 First bead spacer 52 Second bead Spacer 53 Free bead spacer

Claims (8)

a first laminate having a first resin base material and a first alignment film laminated on the first resin base material;
a second resin substrate and a second alignment film laminated on the second resin substrate, wherein the first alignment film and the second alignment film are arranged so as to face each other , a second laminate, and
Liquid crystal molecules arranged between the first laminate and the second laminate, the orientation of which is controlled by applying a voltage to electrodes provided on at least one of the first laminate and the second laminate. a liquid crystal layer comprising
a plurality of bead spacers arranged between the first laminate and the second laminate;
The bead spacers include first bead spacers fixed to the first alignment film, second bead spacers fixed to the second alignment film, and both the first alignment film and the second alignment film. Includes, with no free bead spacers,
the first alignment film includes a plurality of first protrusions protruding toward the liquid crystal layer;
at least a portion of the first protrusion at least partially surrounds the first bead spacer to hold the first bead spacer;
the second alignment film includes a plurality of second protrusions protruding toward the liquid crystal layer;
at least a portion of the second protrusion at least partially surrounds the second bead spacer to hold the second bead spacer;
At least one of the protrusion height of the first protrusion holding the first bead spacer and the protrusion height of the second protrusion holding the second bead spacer is 0.2 μm or more and less than 0.5 μm. , dimming unit. the first alignment film includes a plurality of first protrusions protruding toward the liquid crystal layer;
at least a portion of the first protrusion at least partially surrounds the first bead spacer to hold the first bead spacer;
the second alignment film includes a plurality of second protrusions protruding toward the liquid crystal layer;
at least a portion of the second protrusion at least partially surrounds the second bead spacer to hold the second bead spacer;
The projection height of the first projections other than the first projections holding the first bead spacers and the projection height of the second projections other than the second projections holding the second bead spacers 2. The light control unit according to claim 1, wherein at least one is 0.2 [mu]m or more and less than 0.5 [mu]m. a first laminate having a first resin base material and a first alignment film laminated on the first resin base material;
a second resin substrate and a second alignment film laminated on the second resin substrate, wherein the first alignment film and the second alignment film are arranged so as to face each other , a second laminate, and
Liquid crystal molecules arranged between the first laminate and the second laminate, the orientation of which is controlled by applying a voltage to electrodes provided on at least one of the first laminate and the second laminate. a liquid crystal layer comprising
a plurality of bead spacers arranged between the first laminate and the second laminate;
The bead spacers include first bead spacers fixed to the first alignment film, second bead spacers fixed to the second alignment film, and both the first alignment film and the second alignment film. Includes, with no free bead spacers,
the first alignment film includes a plurality of first protrusions protruding toward the liquid crystal layer;
at least a portion of the first protrusion at least partially surrounds the first bead spacer to hold the first bead spacer;
the second alignment film includes a plurality of second protrusions protruding toward the liquid crystal layer;
at least a portion of the second protrusion at least partially surrounds the second bead spacer to hold the second bead spacer;
The projection height of the first projections other than the first projections holding the first bead spacers and the projection height of the second projections other than the second projections holding the second bead spacers At least one of the light control units is 0.2 μm or more and less than 0.5 μm. The light control unit according to any one of claims 1 to 3, wherein the ratio of the number of said free bead spacers to the number of said bead spacers is 0.1% or more and 5.0% or less. a first laminate having a first resin base material and a first alignment film laminated on the first resin base material;
a second resin substrate and a second alignment film laminated on the second resin substrate, wherein the first alignment film and the second alignment film are arranged so as to face each other , a second laminate, and
Liquid crystal molecules arranged between the first laminate and the second laminate, the orientation of which is controlled by applying a voltage to electrodes provided on at least one of the first laminate and the second laminate. a liquid crystal layer comprising
a plurality of bead spacers arranged between the first laminate and the second laminate;
The bead spacers include first bead spacers fixed to the first alignment film, second bead spacers fixed to the second alignment film, and both the first alignment film and the second alignment film. Includes, with no free bead spacers,
The ratio of the number of free bead spacers to the number of bead spacers is 0.1% or more and 5.0% or less ,
The free bead spacers are those in which the first bead spacers fall off from the first alignment film and/or the second bead spacers fall off due to the pressure applied by the first bead spacers overlapping the second bead spacers. A light control unit that is removed from the second alignment film . The ratio of the projection height [μm] of the first projection holding the first bead spacer to the diameter [μm] of the bead spacer and the projection height of the second projection holding the second bead spacer 5. The light control unit according to claim 1, wherein at least one of the [[mu]m] ratios is 2.2% or more and less than 5.5%. 7. The light control unit according to claim 1, wherein at least one of the thickness of said first alignment film and the thickness of said second alignment film is 60 nm or more and 150 nm or less. a pair of substrates;
The light control unit according to any one of claims 1 to 7 arranged between the pair of substrates.

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