Optical modulation device

Abstract

The present application relates to an optical modulation device. The present application can provide an optical modulation device having excellent optical characteristics including a transmittance variable characteristic by compensating for the characteristics control and appropriate arrangement of a film, and being suitable for various uses by controlling the tilt angle light leakage in a black mode.

Description

Technical Field

[0001] This application relates to optical modulation devices. Background Technology

[0002] An optical modulation device refers to a device capable of switching between at least two or more different states. Such devices are used in a wide range of applications, including wearable devices such as eyeglasses or sunglasses, mobile devices, devices for virtual reality (VR) and augmented reality (AR), and vehicle sunroofs.

[0003] Optical modulation devices typically have a structure including an optical modulation film layer and a polarizing layer disposed on one or both sides of the optical modulation film layer, wherein the optical modulation film layer may include two substrates disposed opposite each other and an optical modulation layer disposed between the substrates.

[0004] Conventionally, inorganic substrates, such as glass substrates, have been used as the substrate. However, recently, considering the various applications described above, attempts have been made to use polymer films as the substrate. However, isotropic polymer films have problems such as weak mechanical strength during the manufacturing process and the tendency to crack or shrink due to heat.

[0005] Therefore, attempts have been made to address these problems by using anisotropic polymer films as substrates. However, anisotropic polymer films suffer from device driving performance issues due to the phase difference of the film, such as light leakage to the sides of the optical modulation device. Summary of the Invention

[0006] Technical issues

[0007] This application relates to an optical modulation device. One object of this application is to provide an optical modulation device that, while possessing excellent optical properties such as variable transmittance, controls omnidirectional light leakage in black mode, etc., has excellent mechanical properties and prevents the occurrence of cracks, etc., thus making it suitable for various applications.

[0008] Technical solution

[0009] The angles defined in this specification should be understood in light of errors such as manufacturing errors or variations. For example, in this specification, the terms vertical, parallel, orthogonal, horizontal, or any numerical value mean substantially vertical, parallel, or orthogonal, horizontal, or any numerical value to the extent that they do not impair the stated purpose and effect. For example, each case may include an error within approximately ±10 degrees, approximately ±5 degrees, approximately ±3 degrees, approximately ±2 degrees, approximately ±1 degree, or approximately ±0.5 degrees.

[0010] Unless otherwise stated, the physical properties mentioned in this specification, when the measurement temperature affects the relevant physical properties, are physical properties measured at room temperature.

[0011] In this specification, the term room temperature refers to the temperature under conditions where it is not specifically heated or cooled, and may mean any temperature in the range of about 10°C to 30°C, for example, about 15°C or greater, 18°C ​​or greater, 20°C or greater, or about 23°C or greater and about 27°C or less. Furthermore, unless otherwise stated, the unit of temperature mentioned in this specification is °C.

[0012] In this specification, the plane phase difference (R) in ) can refer to the value calculated by the following Equation 1, and the phase difference (R) in the thickness direction. th ) can refer to the value calculated using the following equation 2.

[0013] [Equation 1]

[0014] R in =dx(n x -n y )

[0015] [Equation 2]

[0016] R th =d×(n z -n y )

[0017] In Equations 1 and 2, R in It can be a planar phase difference, R th The phase difference can be in the thickness direction, where d can be the thickness of the layer, and n can be the phase difference in the thickness direction. x This can be the refractive index of the layer along the slow axis, and n y It can be the refractive index of the layer in the fast axis direction and the refractive index in the plane direction orthogonal to the slow axis direction, and n z It can be the refractive index of the layer in the thickness direction.

[0018] Here, the term "layer" refers to the layer used for measuring planar phase difference and / or thickness-direction phase difference. For example, a layer can be a polarizing layer, a polymer film substrate, an optical modulation layer, a -C plate, an adhesive layer (or a pressure-sensitive adhesive layer), or a liquid crystal alignment film, etc.

[0019] Unless otherwise stated, the term tilt angle used in this specification is defined as follows. Figure 6 In this context, when the plane formed by the x-axis and y-axis is used as the reference plane (for example, the reference plane can be the surface of a polarizing layer, polymer film substrate, optical modulation layer, -C plate, adhesive layer (or pressure-sensitive adhesive layer), or liquid crystal alignment film in an optical modulation device), it will be as follows: Figure 6 The angle formed by the z-axis relative to the normal to the reference plane is defined as the tilt angle (in Figure 6 In the equation, the angle of inclination at point P is Θ). Figure 6 In this process, when the plane formed by the x-axis and y-axis is used as the reference plane (for example, the reference plane can be the surface of a polarizing layer, polymer film substrate, optical modulation layer, -C plate, adhesive layer (or pressure-sensitive adhesive layer), or liquid crystal alignment film in an optical modulation device), the x-axis of the reference plane is set to 0 degrees, and then... Figure 6 The angle formed relative to the relevant x-axis is defined as the radial angle (in Figure 6 In this context, the radial angle at point P is Φ. Here, the x-axis of the reference plane can refer to, for example, the axis in the horizontal direction of the reference plane.

[0020] Unless otherwise stated, the phase difference, refractive index, refractive index anisotropy, etc. mentioned in this specification are physical quantities for light with a wavelength of approximately 550 nm.

[0021] Unless otherwise stated, the angles formed by any two directions mentioned herein can be acute angles ranging from acute to obtuse angles formed by the two directions, or they can be small angles from angles measured in the clockwise and counterclockwise directions. Therefore, unless otherwise stated, the angles mentioned herein are positive. However, if necessary, to indicate the direction of measurement between angles measured in the clockwise or counterclockwise direction, angles measured in the clockwise direction may be represented as positive numbers, and angles measured in the counterclockwise direction may be represented as negative numbers.

[0022] The optical modulation device of this application may include an optical modulation film layer in which a first substrate, an optical modulation layer, and a second substrate are sequentially formed. For example, the first substrate may be a first polymer film substrate with an adhesive layer or a pressure-sensitive adhesive layer formed on a first surface, and the second substrate may be a second polymer film substrate with a liquid crystal alignment film formed on a first surface. A polarizing layer may be attached to a second surface of the first substrate and / or a second surface of the second substrate.

[0023] In this specification, for convenience, the polarizing layer that can be attached to the second surface of the first substrate may be referred to as the first polarizing layer, and the polarizing layer that can be attached to the second surface of the second substrate may be referred to as the second polarizing layer.

[0024] In this specification, the first surface of the substrate refers to either the main surface or the opposite surface of the substrate, and the second surface refers to the other surface of the main surface or the opposite surface of the substrate.

[0025] The first polymer membrane substrate and the second polymer membrane substrate can be configured such that their first surfaces face each other.

[0026] The optical modulation device of this application may include a -C plate, for example, at at least one of the following locations: between the optical modulation layer and the first polymer film and / or between the optical modulation layer and the second polymer film substrate. Specifically, the -C plate may be present between the pressure-sensitive adhesive layer or adhesive layer and the first polymer film substrate, between the pressure-sensitive adhesive layer or adhesive layer and the optical modulation layer, between the liquid crystal alignment film and the second polymer film substrate, or between the liquid crystal alignment film and the optical modulation layer. The -C plate may be present in only one of the aforementioned locations, or may be present in two or more locations. In this specification, the term -C plate refers to a film with a different refractive index in the thickness direction (z-axis), meaning a layer that satisfies the refractive index relationship nx = ny > nz or nx > ny > nz. Here, nx is the refractive index of the layer in the slow axis direction, ny is the refractive index in the fast axis direction, and nz is the refractive index in the normal direction of the plane formed by the slow axis and the fast axis. When the -C plate satisfies the relationship nx>ny>nz, the plane phase difference can be about 30nm or less, about 25nm or less, about 20nm or less, about 15nm or less, about 10nm or less, about 5nm or less, about 4nm or less, about 3nm or less, about 2nm or less, or about 1nm or less, or it can be greater than 0nm.

[0027] In one instance, such as Figure 1 As shown, the optical modulation device of this application may include: a first substrate 100 in which a first polarizing layer 101, a first polymer film substrate 102, a -C plate 600 and a pressure-sensitive adhesive layer or adhesive layer 103 are sequentially formed; an optical modulation layer 300; and a second substrate 200 in which a liquid crystal alignment film 203, a second polymer film substrate 202 and a second polarizing layer 201 are sequentially formed.

[0028] In another instance, such as Figure 2 As shown, the optical modulation device of this application may include: a first substrate 100 in which a first polarizing layer 101, a first polymer film substrate 102 and a pressure-sensitive adhesive layer or adhesive layer 103 are sequentially formed; an optical modulation layer 300; and a second substrate 200 in which a liquid crystal alignment film 203, a -C plate 600, a second polymer film substrate 202 and a second polarizing layer 201 are sequentially formed.

[0029] In another instance, such as Figure 3 As shown, the optical modulation device of this application may include: a first substrate 100 in which a first polarizing layer 101, a first polymer film substrate 102, a -C plate 600 and a pressure-sensitive adhesive layer or adhesive layer 103 are sequentially formed; an optical modulation layer 300; and a second substrate 200 in which a liquid crystal alignment film 203, a -C plate 600, a second polymer film substrate 202 and a second polarizing layer 201 are sequentially formed.

[0030] exist Figures 1 to 3 In the structure, either the first polarizing layer 101 or the second polarizing layer 201 can be omitted.

[0031] The inventors have determined that light leakage that can occur in an optical modulation device when viewed from the side can be prevented by: appropriately arranging a compensation film, such as a -C plate, on the first and / or second substrates at the aforementioned locations, as described above, and controlling the characteristics to be described below.

[0032] In this application, for example, the -C plate can have an absolute value (C) of the thickness direction phase difference that satisfies condition 1 below. Here, the thickness direction phase difference of the -C plate can be negative.

[0033] [Condition 1]

[0034] C≤D×1.2

[0035] In condition 1, D can refer to the value of the phase difference in the thickness direction of the light modulation layer × (average refractive index of the liquid crystal compound contained in the light modulation layer / average refractive index of the -C plate) when the light modulation device of this application is vertically aligned. Here, for example, to solve the problem of light leakage when the phase difference of the light modulation layer occurs while viewing the light modulation device of this application from an inclined angle, a compensation film, such as the -C plate, can compensate for the phase difference of the light modulation layer, etc., and for this purpose, condition 1 above can be related to the control characteristics of the -C plate. In another example, C in condition 1 above can be D × 1.19 or less, D × 1.18 or less, D × 1.17 or less, D × 1.16 or less, D × 1.15 or less, D × 1.14 or less, D × 1.13 or less, D × 1.12 or less, D × 1.11 or less, D × 1.10 or less, D × 1.09 or less, D × 1.08 or less, D × 1.07 or less, D... ×1.06 or smaller, D×1.05 or smaller, D×1.04 or smaller, D×1.03 or smaller, D×1.02 or smaller, or D×1.01 or smaller, or D×0.1 or larger, D×0.2 or larger, D×0.3 or larger, D×0.4 or larger, D×0.5 or larger, D×0.6 or larger, D×0.7 or larger, D×0.8 or larger, or D×0.9 or larger. The characteristics of the -C plate and the light modulation layer can be designed to meet the above condition 1, taking into account, for example, light leakage in black mode and / or changes in tilt angle color in transmission mode.

[0036] Here, the vertical orientation of the light modulation layer can be the initial orientation of the light modulation layer as described below. Furthermore, the average refractive index of the liquid crystal compound contained in the light modulation layer can be measured using the method described in Evaluation Example 4 below.

[0037] The absolute value (C) of the phase difference in the thickness direction of the C-C plate for condition 1 above can be in the range of, for example, 100 nm to 950 nm. In another example, the range can be 150 nm or greater, 200 nm or greater, 250 nm or greater, 300 nm or greater, 350 nm or greater, 400 nm or greater, 450 nm or greater, 500 nm or greater, 550 nm or greater, 600 nm or greater, 650 nm or greater, or 700 nm or greater, or it can also be 900 nm or less, 850 nm or less, 800 nm or less, 750 nm or less, 700 nm or less, 650 nm or less, 600 nm or less, or approximately 550 nm or less. Figure 1 or Figure 2 When a -C layer is introduced, C in condition 1 can be the absolute value of the phase difference in the thickness direction of a -C layer, and when... Figure 3 When two layers or three or more layers are introduced, it can refer to the absolute value of the sum of the phase differences in the thickness direction of all -C plates.

[0038] In this application, the -C plate can be formed from a blend of polyamides, for example, in a solvent, but its use is not limited as long as it possesses the aforementioned properties. In one example, the polyamide can be formed by polymerizing 2,2'-bis(trifluoromethyl)-5,5'-biphenyldiamine with isophthalic acid and / or terephthalic acid. Furthermore, in one example, the solvent can be dimethylacetamide. The polyamide can be contained, for example, in the range of about 4% to 10% by weight relative to the solvent, and in another example, the polyamide can be contained in the range of 4.5% by weight or more, or 5% by weight or more, or in the range of 9% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, or 5.5% by weight or less.

[0039] In one example, a -C plate can be obtained by coating by applying a solution of a blended polyamide in a solvent onto a polymer film substrate or conductive layer, for example, by rod coating. The -C plate layer formed by coating can be cured by thermosetting or UV curing, etc.

[0040] In this application, the thickness of the -C plate after curing can range from, for example, 1 μm to 15 μm. In another example, it can be 2 μm or greater, 3 μm or greater, 4 μm or greater, or 5 μm or greater, or it can be 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, or 7 μm or less.

[0041] As mentioned above, the phase difference (R) in the thickness direction of the optical modulation layer th It can be obtained from Equation 2.

[0042] [Equation 2]

[0043] R th =d×(n z -n y )

[0044] In Equation 2, R th The phase difference can be in the thickness direction, where d can be the thickness of the layer, and n can be the phase difference in the thickness direction. y This can be the refractive index of the layer along the fast axis, and n z The refractive index can be oriented along the thickness of the layer. Here, d can be, for example, the thickness of the optical modulation layer, and typically, it can be approximately the same as the height of the spacer. The height of the spacer can be determined using a measuring device (Optical profiler, Nano system, Nano View-E1000).

[0045] In this application, the phase difference in the thickness direction of the optical modulation layer can, for example, be in the range of about 500 nm to 900 nm. In another example, it can be about 550 nm or greater, about 600 nm or greater, about 650 nm or greater, about 700 nm or greater, or about 750 nm or greater, or it can be about 850 nm or less, or about 800 nm or less.

[0046] The average refractive index of the liquid crystal compound contained in the light modulation layer and the average refractive index of the -C plate can be determined using an Abbe refractometer, and the specific method can follow the method disclosed in Evaluation Example 4 below.

[0047] In this application, the average refractive index of the liquid crystal compound contained in the light modulation layer can, for example, be in the range of 0.5 to 3.5. In another example, it can be 1 or greater, 1.1 or greater, 1.2 or greater, 1.3 or greater, 1.4 or greater, or 1.5 or greater, or it can be 3 or less, 2.5 or less, 2 or less, 1.9 or less, 1.8 or less, 1.7 or less, or 1.6 or less.

[0048] In this application, the average refractive index of the -C plate can be, for example, in the range of 0.5 to 3.5. In another example, it can be 1 or greater, 1.2 or greater, 1.3 or greater, 1.4 or greater, 1.5 or greater, or 1.6 or greater, or it can be 3 or less, 2.5 or less, 2 or less, 1.9 or less, 1.8 or less, or 1.7 or less.

[0049] In this application, even when using the anisotropic film substrate described below as the first polymer film substrate and the second polymer film substrate, by arranging -C plates with such characteristics in a suitable position, the problem of distortion of the compensation effect due to the optical properties of the anisotropic film substrate can be solved while controlling light leakage to the side.

[0050] In this application, the first polymer film substrate and / or the second polymer film substrate may be anisotropic. For example, the planar phase difference between each of the first polymer film substrate and / or the second polymer film substrate with respect to a wavelength of 550 nm may be 500 nm or greater. In another example, it may be 1000 nm or greater, 2000 nm or greater, 3000 nm or greater, 4000 nm or greater, 5000 nm or greater, 6000 nm or greater, 7000 nm or greater, 8000 nm or greater, 9000 nm or greater, or 10000 nm or greater, or it may be 50000 nm or less, 40000 nm or less, 30000 nm or less, 20000 nm or less, or 15000 nm or less, and is not limited thereto.

[0051] Films exhibiting such high phase differences are well-known in industry, and such films exhibit large optical anisotropy and large asymmetric mechanical properties due to high stretching during manufacturing. Representative examples of retardation films known in industry can include polyester films, such as PET (poly(ethylene terephthalate)) films.

[0052] In this application, based on the content of the optical modulation device of this application to be described below, the effect of preventing lateral light leakage can be further improved by appropriately introducing the aforementioned -C plate and anisotropic film substrate.

[0053] In the optical modulation device of this application, a first polymer film substrate and a second polymer film substrate may be included in the device, such that the slow axes of the first polymer film substrate and the second polymer film substrate have a specific positional relationship. In one example, the slow axes of the first polymer film substrate and the second polymer film substrate may be horizontal to each other.

[0054] By arranging a first polymer film substrate and a second polymer film substrate having such a planar phase difference, such that the slow axis of the polymer film substrate has the above range, a light modulation device can be provided that effectively controls omnidirectional light leakage in black mode while exhibiting excellent effects in changing transmittance, through combination with -C plates, etc.

[0055] The first polymer film substrate and / or the second polymer film substrate of this application may each include, for example, a first polarizing layer and / or a second polarizing layer on one side of the polymer film substrate. In this specification, a polarizing layer can refer to an element that converts natural light or unpolarized light into polarized light. In one example, the polarizing layer may be a linear polarizing layer. In this specification, a linear polarizing layer means a situation where the light selectively transmitted is linearly polarized light vibrating in any direction, and the light selectively absorbed or reflected is linearly polarized light vibrating in a direction orthogonal to the vibration direction of the linearly polarized light. That is, the linear polarizing layer may have a transmission axis and an absorption axis or reflection axis orthogonal to the plane direction.

[0056] The polarizing layer can be either an absorptive polarizing layer or a reflective polarizing layer. As an absorptive polarizing layer, for example, a polarizing layer in which iodine is dyed on a polymer stretched film such as a PVA (PVA refers to polyvinyl alcohol in this specification) stretched film can be used, or a host-guest type polarizing layer in which liquid crystal polymerized in an oriented state is set as the host and anisotropic dyes arranged according to the orientation of the liquid crystal are set as guests, is used, and is not limited thereto. As a reflective polarizing layer, for example, a reflective polarizing layer called a DBEF (Dual Brightness Enhancement Film) or a reflective polarizing layer formed by coating a liquid crystal compound such as LLC (Lyotropic liquid crystal) can be used, and is not limited thereto.

[0057] In one example, the absorption axes of the first and second polarizing layers can be arranged perpendicular to each other. Since the optical modulation device of this application controls omnidirectional light leakage (especially in black mode) through such an arrangement, it can provide an optical modulation device that exhibits excellent transmittance variable effects while effectively achieving a dark state.

[0058] Furthermore, when a polarizing layer is included, the absorption axis can be perpendicular or horizontal to the slow axis of the polymer film substrate.

[0059] In one example, the frontal transmittance of the optical modulation device of this application in black mode can be 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, or 0.3% or less. In black mode, a lower frontal transmittance is more advantageous; therefore, there is no particular limitation on the lower limit of the frontal transmittance in black mode. In one example, the upper limit of the transmittance in transmission mode can be approximately 100%, and the lower limit of the frontal transmittance in black mode can be approximately 0%.

[0060] In one example, the frontal transmittance of the optical modulation device of this application in transmission mode can be 20% or greater, and in another example, it can be approximately 21% or greater, 22% or greater, 23% or greater, 24% or greater, 25% or greater, 30% or greater, 35% or greater, 40% or greater, 45% or greater, 50% or greater, 55% or greater, 60% or greater, 65% or greater, 70% or greater, 75% or greater, or 80% or greater. A higher frontal transmittance in transmission mode is more advantageous; therefore, there is no particular upper limit to the frontal transmittance in transmission mode, and in one example, the upper limit of the frontal transmittance in transmission mode can be approximately 100%.

[0061] In one example, the difference in frontal transmittance between the optical modulation device of this application in the transmission mode state and the black mode state can be 15% or more, 16% or more, 17% or more, 18% or more, 19% or more, 20% or more, 25% or more, 30% or more, 35% or more, or 40% or more, or it can be 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less, or 45% or less.

[0062] Frontal transmittance can be, for example, linear transmittance. Linear transmittance can be the percentage ratio of light transmitted in the same direction as the incident direction to the light incident on the light modulation device. For example, if the device is in the form of a film or sheet, the frontal transmittance can be defined as the percentage of light incident in a direction parallel to the z-axis (which is the normal direction to the surface of the film or sheet) that passes through the device in a direction parallel to the normal direction.

[0063] Frontal transmittance or reflectance can each be the frontal transmittance or reflectance for any wavelength in the visible light region, such as from about 400 nm to 700 nm or from about 380 nm to 780 nm, or the frontal transmittance or reflectance for the entire visible light region, the maximum or minimum frontal transmittance or reflectance for the entire visible light region, or the average of the frontal transmittance or reflectance for the visible light region. In another example, frontal transmittance can be the frontal transmittance for light with a wavelength of about 550 nm.

[0064] In one example, the maximum transmittance of the light modulation device of this application in black mode may be less than 10%. In this specification, tilt angle transmittance can be the transmittance of light passing through the measuring object parallel to an axis with a tilt angle Θ relative to the z-axis direction, where the z-axis direction is the normal direction of a reference plane of the measuring object (e.g., the reference plane can be the surface of a polarizing layer, polymer film substrate, light modulation layer, -C plate, adhesive layer (or pressure-sensitive adhesive layer), or liquid crystal alignment film, etc., in the light modulation device), and the maximum value of tilt angle transmittance can refer to the maximum transmittance value obtained by measuring the transmittance of light at the tilt angle Θ while changing the radial angle Φ from 0 degrees to 360 degrees. The tilt angle Θ and the radial angle Φ can be... Figure 6 The same applies. In another instance, it can be less than 9%, less than 8%, or less than 7%, or it can be 0% or greater, 1% or greater, 2% or greater, 3% or greater, 4% or greater, 5% or greater, or 6% or greater, and is not limited thereto.

[0065] In this application, the gap between the opposing first polymer film substrate and the second polymer film substrate can be maintained by a spacer in the form of a separator. In one example, such as... Figure 4 As shown, a first polarizing layer 101, a first polymer film substrate 102, a -C plate 600, a pressure-sensitive adhesive layer or adhesive layer 103, a light modulation layer 300, a liquid crystal alignment film 203, a second polymer film substrate 202, and a second polarizing layer 201 are sequentially formed, wherein the gap (G) between the first polymer film substrate and the second polymer film substrate can be maintained by a spacer 500 in the form of a separator. In this case, the light modulation layer 300 can exist in regions where the spacer 500 is not present.

[0066] In this application, the shape and arrangement of the spacers can be appropriately designed, for example, within a range that allows for maintaining a certain interval between the second substrate and the first substrate.

[0067] The spacers of this application may be present to form partitions by means of the spacer shape, or spacers may be present to separate two or more columnar shapes, but are not limited thereto. In one example, the spacers may have quadrilateral, triangular, or honeycomb spacer shapes. Quadrilateral spacer shapes may be suitable for effectively controlling angled light leakage in black mode, and square or rectangular spacer shapes may be suitable, but are not limited thereto.

[0068] In this application, the arrangement of the spacers can be appropriately selected without prejudice to the purpose of this application, such as the spacing, line width, height, and area ratio in the upper or second substrate. Here, the area ratio refers to the percentage of the area in which the spacers are formed relative to the total area of ​​the first surface of the second substrate.

[0069] In this specification, the term "spacer spacing" refers to the interval between facing sides or the interval between facing vertices and sides, which is determined when the spacer is viewed from above. In this specification, "viewing the spacer from above" means viewing the spacer parallel to the normal direction to the surface of the polymer film substrate on which the spacer is formed. In one example, when the spacer has a triangular separator shape, the term "spacer spacing" may refer to the perpendicular distance between the vertex of the triangle and the side facing the vertex. In another example, when the spacer has a quadrilateral separator shape, the term "spacer spacing" may refer to the length of each side of the quadrilateral. When all the sides of the quadrilateral are the same length (i.e., when the quadrilateral is a square), the same length of the sides can be defined as the spacing; and when the sides are not the same length (e.g., when the quadrilateral is a rectangle), the arithmetic mean of the lengths of all the sides can be defined as the spacing. In another instance, when the spacer has a honeycomb-like divider shape (in the case of a hexagon), the term spacing can refer to the spacing between opposite sides of the hexagon, and when the spacing between all opposite sides is the same, the length of the same spacing between the sides can be defined as the spacing, and when the spacing between the sides is not the same, the arithmetic mean of the lengths of all the spacing between the sides can be defined as the spacing.

[0070] In this application, the spacing of the spacers can be, for example, from 50 μm to 500 μm, and in another instance, it can be 100 μm or greater, 150 μm or greater, 200 μm or greater, 250 μm or greater, 300 μm or greater, or 350 μm or greater, or it can be 450 μm or less, 400 μm or less, or 350 μm or less.

[0071] In this specification, the term linewidth refers to the dimension defined in the direction perpendicular to the longitudinal direction of the spacer when viewed from above. The linewidth of the spacer can be, for example, from 1 μm to 50 μm, and in another instance, it can be 2 μm or greater, 3 μm or greater, 4 μm or greater, 5 μm or greater, 6 μm or greater, 7 μm or greater, 8 μm or greater, 9 μm or greater, 10 μm or greater, 11 μm or greater, 12 μm or greater, 13 μm or greater, 14 μm or greater, 15 μm or greater, or 16 μm or greater, or it can be 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 19 μm or less, 18 μm or less, 17 μm or less, or 16 μm or less.

[0072] Furthermore, the term "spacer height" generally corresponds to the thickness (cell gap) of the optical modulation layer and refers to the size of the spacer measured in the normal direction of the surface of the polymer film substrate as described above. In this application, the height of the spacer can be adjusted to take into account the spacing between the first and second substrates. For example, the height of the spacer can be from 1 μm to 20 μm, and in another example, it can be 2 μm or greater, 3 μm or greater, 4 μm or greater, 5 μm or greater, 6 μm or greater, 7 μm or greater, or 8 μm or greater, or it can be 19 μm or less, 18 μm or less, 17 μm or less, 16 μm or less, 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, or 6 μm or less. In one example, the height of the spacer can be approximately the same as the thickness of the optical modulation layer.

[0073] In this specification, when the area of ​​the polymer membrane substrate is A and the area therein where spacers are formed is B, the term area ratio refers to a value obtained by multiplying the ratio of the area (A) of the polymer membrane substrate to the area (B) where spacers are formed by 100, i.e., 100 × B / A. In this application, the area ratio of the spacers can be from about 0.1% to 50% relative to the first or second polymer membrane substrate. In this application, as the area ratio of the spacers increases, the adhesive force (or cohesive force) of the first and second polymer membrane substrates can increase. In another example, it can be 1% or greater, 2% or greater, 3% or greater, 4% or greater, 5% or greater, 6% or greater, 7% or greater, 8% or greater, or 9% or greater, or it can be 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, or 9% or less.

[0074] In this application, the spacer may comprise, for example, a curable resin. The curable resin may be, for example, a thermosetting resin or a photocurable resin, such as a UV-curable resin, but is not limited thereto. Thermosetting resins may be, for example, silicone resins, furan resins, polyurethane resins, epoxy resins, amino resins, phenolic resins, urea resins, polyester resins, or melamine resins, but are not limited thereto. As a UV-curable resin, acrylic resins are typically used, such as polyester acrylate polymers, polystyrene acrylate polymers, epoxy acrylate polymers, polyurethane acrylate polymers, polybutadiene acrylate polymers, silicone acrylate polymers, or alkyl acrylate polymers, but are not limited thereto. In one example, the spacer may be formed using an acrylic polymer, more specifically a polyester-based acrylate polymer, but is not limited thereto; and in another example, it may also be formed using a silicone polymer. When the spacer is formed using a silicone polymer, the silicone polymer retained in the concave regions of the spacer can serve as a vertical alignment film, such that, as described below, no additional vertical alignment film may be used on the substrate in which the spacer is located. As an organosilicon polymer, known polymers with silicon and oxygen bonds (Si-O-Si) as the main axis, such as polydimethylsiloxane (PDMS), can be used, but are not limited thereto.

[0075] By controlling the shape and / or arrangement of the spacers as described above, this application can provide an optical modulation device in which the unit gaps are properly maintained, the adhesion (or cohesion) between the upper and lower membrane substrates is excellent, and light leakage in black mode is also properly controlled.

[0076] In this application, the light modulation layer is a layer containing at least a liquid crystal compound, which can refer to a liquid crystal layer in which the orientation state of the liquid crystal compound can be controlled by applying an external signal. The liquid crystal compound can be, for example, a nematic liquid crystal compound, a smectic liquid crystal compound, or a cholesteric liquid crystal compound, and is not limited thereto, as long as its orientation direction can be changed by applying an external signal. In one example, the liquid crystal compound can be, for example, a compound without any polymerizable or crosslinkable groups, or a compound that does not polymerize or crosslink even if it has such groups, such that its orientation direction can be changed by applying an external signal.

[0077] The light modulation layer of this application may also include, for example, a dichroic dye along with a liquid crystal compound. In this application, the term "dye" may refer to a material capable of strongly absorbing and / or altering light in at least a portion or all of the visible light region, for example, in the range of 400 nm to 700 nm, and the term "dichroic dye" may refer to a material capable of anisotropically absorbing light in at least a portion or all of the visible light region. Such dyes are known, for example, azo dyes or anthraquinone dyes, but are not limited thereto.

[0078] In one example, the light modulation layer is a liquid crystal layer comprising liquid crystal and dichroic dyes, which can be a so-called guest-host liquid crystal cell (GHLC layer). The term "GHLC layer" can refer to a functional film in which dichroic dyes are arranged together according to the liquid crystal alignment to exhibit anisotropic light absorption characteristics with respect to the alignment direction of the dichroic dyes and in a direction perpendicular to that alignment direction. For example, a dichroic dye is a substance whose light absorptivity changes with the polarization direction, wherein if the absorptivity of light polarized in the long axis direction is large, it can be called a p-type dye, and if the absorptivity of light polarized in the short axis direction is large, it can be called an n-type dye. In one example, when a p-type dye is used, polarized light vibrating in the long axis direction of the dye can be absorbed, while polarized light vibrating in the short axis direction of the dye may be less absorbed and transmitted. In the following text, unless otherwise stated, the dichroic dye is considered to be a p-type dye.

[0079] For example, this application may relate to an apparatus designed such that, by adjusting the arrangement of liquid crystal compounds in a light modulation layer, the initial orientation is vertical, and the vertical orientation state can be changed to a horizontal orientation state by applying an external signal. Here, the initial orientation is the orientation state when no external signal is applied to the light modulation layer.

[0080] In this specification, the term "vertical orientation" refers to a state in which the director of the light modulation layer or the director of the liquid crystal compound in the light modulation layer is arranged substantially perpendicular to the plane of the light modulation layer. For example, the angle formed by the z-axis, which is the normal to the surface of the light modulation layer, and the director can be in the range of about 80 degrees to 100 degrees or 85 degrees to 95 degrees, or it can be about 90 degrees. Furthermore, the term "horizontal orientation" can mean a state in which the director of the light modulation layer or the director of the liquid crystal compound in the light modulation layer is arranged substantially parallel to the reference plane of the light modulation layer. For example, the angle formed by the director and the reference plane of the light modulation layer can be in the range of about 0 degrees to 10 degrees or about 0 degrees to 5 degrees, or it can be about 0 degrees.

[0081] In this specification, the terms "direction of the light modulation layer" or "direction of the liquid crystal compound" may refer to the optical axis or slow axis of the light modulation layer. For example, the optical axis or slow axis may refer to the direction of the long axis when the liquid crystal molecules are rod-shaped, and may refer to the axis in the normal direction of the disk plane when the liquid crystal molecules are disk-shaped. When the light modulation layer contains a plurality of liquid crystal compounds with different directions, the optical axis or slow axis may refer to the vector sum of the directions of the liquid crystal compounds.

[0082] In one example, the light modulation layer can be designed to achieve a twisted alignment mode. For this purpose, the light modulation layer can comprise a chiral dopant and a liquid crystal compound. In this specification, the term "twisted alignment mode" can mean that the director of the liquid crystal compound is twisted along an imaginary helical axis and simultaneously aligned to form a helical structure of the layer. The twisted alignment mode can be achieved in the aforementioned vertical and / or horizontal alignment modes. For example, a vertical twisted alignment mode is a layered state in which the individual liquid crystal compounds are twisted along the helical axis in a vertically aligned state, and a horizontal twisted alignment mode can mean a layered state in which the individual liquid crystal compounds are twisted along the helical axis in a horizontally aligned state.

[0083] In the twisted orientation mode, the ratio (d / p) of the thickness (d, inter-cell gap) to the spacing (p) of the optical modulation layer can be, for example, 1 or less. When the ratio (d / p) exceeds 1, problems such as finger domain may occur, and therefore the range can be adjusted to the above range if possible. In another example, the ratio (d / p) can be about 0.95 or less, about 0.9 or less, about 0.85 or less, about 0.8 or less, about 0.75 or less, about 0.7 or less, about 0.65 or less, about 0.6 or less, about 0.55 or less, about 0.5 or less, about 0.45 or less, about 0.4 or less, or about 0.35 or less, or it can also be about 0.1 or greater, about 1.15 or greater, about 0.2 or greater, about 0.25 or greater, about 0.3 or greater, or about 0.35 or greater. Here, the thickness (d) of the optical modulation layer can have the same meaning as the cell gap in the optical modulation device.

[0084] The spacing (p) of the optical modulation layer in the twisted orientation mode can be measured using a wedge cell measurement method, specifically, it can be measured using the method described in D. Podolskyy et al.'s Simple method for accurate measurement of the cholesteric pitch using a "stripe-wedge Grandjean-Cano cell" (Liquid Crystals, Vol. 35, No. 7, July 8, 2008, 789-791).

[0085] The optical modulation layer can also contain so-called chiral dopants, which enable the optical modulation layer to achieve a twisted mode.

[0086] Chiral dopants that can be included in the light modulation layer can be used without particular restrictions, as long as they can induce the desired rotation (twisting) without degrading the liquid crystal properties, such as nematic regularity. Chiral dopants used to induce rotation in liquid crystal molecules need to include at least chirality in their molecular structure. Examples of chiral dopants include, for example, compounds having one or two or more asymmetric carbons; compounds having asymmetric sites on heteroatoms, such as chiral amines or chiral sulfoxides; or compounds having axial asymmetry and optically active sites, such as cumulative polyenes or binatol. Chiral dopants can be, for example, low molecular weight compounds with a molecular weight of 1500 or less. Commercially available chiral nematic liquid crystals can be used as chiral dopants, for example, the chiral doped liquid crystal S811 from Merck Co., Ltd. or BASF's LC756.

[0087] There are no particular restrictions on the application ratio of chiral dopants, as long as the desired ratio (d / p) can be achieved. Typically, the content (wt%) of chiral dopants is calculated using the equation 100 / (HTP (helical twisting power) × spacing (nm)), which can be selected with the desired spacing (p) in mind at an appropriate ratio.

[0088] The optical modulation layer may comprise a liquid crystal compound with negative dielectric anisotropy, or the optical modulation layer may exhibit the aforementioned dielectric anisotropy. The absolute value of the dielectric anisotropy may be appropriately selected for the purposes of this application. The term "dielectric anisotropy (Δε)" may refer to the difference (ε / / -ε⊥) between the horizontal dielectric constant (ε / / ) and the vertical dielectric constant (ε⊥). In this specification, the term horizontal dielectric constant (ε / / ) refers to the dielectric constant measured along the direction of the electric field when a voltage is applied such that the direction of the liquid crystal's director and the direction of the electric field generated by the applied voltage are substantially horizontal, and the term vertical dielectric constant (ε⊥) refers to the dielectric constant measured along the direction of the electric field when a voltage is applied such that the direction of the liquid crystal's director and the direction of the electric field generated by the applied voltage are substantially perpendicular.

[0089] The liquid crystal layer may contain a liquid crystal compound with a refractive index anisotropy (Δn) in the range of about 0.04 to 0.15, or the liquid crystal layer may exhibit the aforementioned refractive index anisotropy. The refractive index anisotropy (Δn) mentioned in this application is the difference (ne-no) between the unusual refractive index (ne) and the ordinary refractive index (no), which can be determined using an Abbe refractometer, specifically according to the method disclosed in Evaluation Example 4 below. In another example, the refractive index anisotropy (Δn) may be about 0.14 or less, 0.13 or less, 0.12 or less, 0.11 or less, or 0.1 or less, or it may be 0.05 or greater, 0.06 or greater, 0.07 or greater, 0.08 or greater, or 0.09 or greater.

[0090] In this specification, the term refractive index anisotropy (Δn) is the difference (ne-no) between the unusual refractive index (ne) and the ordinary refractive index (no), which can be determined using an Abbe refractometer. The specific method follows the procedures disclosed in the following examples.

[0091] The thickness of the optical modulation layer in this application can be appropriately selected to suit the purposes of this application. In one example, the thickness of the optical modulation layer can be about 15 μm or less. By controlling the thickness in this way, a device with a large transmittance difference between the transmission mode and the black mode can be realized, that is, a device with excellent transmittance variable characteristics. In another example, the thickness can be about 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, or 7 μm or less, or it can be 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, 6 μm or more, or 7 μm or more, but is not limited thereto.

[0092] By controlling the thickness as described above, a device with a large frontal transmittance difference in both transmission and black modes can be achieved, i.e., a device with excellent variable transmittance characteristics.

[0093] In the optical modulation apparatus of this application, for example, an adhesive layer or pressure-sensitive adhesive layer may be formed on one side of the first polymer film substrate. In one example, the adhesive layer or pressure-sensitive adhesive layer may comprise an adhesive or pressure-sensitive adhesive having vertical alignment forces. In this specification, the term adhesive or pressure-sensitive adhesive having vertical alignment forces may mean a material having both adhesiveness (or cohesive force) and vertical alignment forces on liquid crystal molecules.

[0094] In one example, an adhesive or pressure-sensitive adhesive with vertical alignment force may be formed on at least one of the surfaces of the first polymer film substrate and the second polymer film substrate. According to one example of this application, an adhesive or pressure-sensitive adhesive with vertical alignment force may be present on one surface of the first polymer film substrate, and a liquid crystal alignment film may be formed on one side of the second polymer film substrate.

[0095] In this application, silicone adhesives or pressure-sensitive adhesives, for example, can be used as adhesives or pressure-sensitive adhesives with vertical orientation forces. As silicone adhesives or pressure-sensitive adhesives, cured products comprising compositions containing curable silicone compounds can be used. The type of curable silicone compound is not particularly limited, and for example, thermocurable silicone compounds or UV-curable silicone compounds can be used.

[0096] In one example, the curable silicone composition is an addition-curable silicone composition, which may include (1) an organopolysiloxane containing two or more alkenyl groups in its molecule and (2) an organopolysiloxane containing two or more hydrogen atoms bonded to silicon in its molecule. Such silicone compounds can, for example, form cured products through an addition reaction in the presence of a catalyst such as a platinum catalyst.

[0097] (1) The organopolysiloxane, which is the main component constituting the organosilicon cured product, contains at least two alkenyl groups in one molecule. Specific examples of alkenyl groups include vinyl, allyl, butenyl, pentenyl, hexenyl, or heptenyl, etc., and vinyl is generally used, but not limited thereto. In (1) the organopolysiloxane, the bonding position of the alkenyl groups as described above is not particularly limited. For example, the alkenyl group can be bonded to the end of the molecular chain and / or to the side chain of the molecular chain. In addition, in (1) the organopolysiloxane, the types of substituents that may be included besides the alkenyl groups mentioned above may include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, or heptyl; aryl groups such as phenyl, tolyl, xylyl, or naphthyl; aralkyl groups such as benzyl or phenyl; halogen-substituted alkyl groups such as chloromethyl, 3-chloropropyl, or 3,3,3-trifluorophenyl; etc., and methyl or phenyl is generally used, but not limited thereto.

[0098] (1) There are no particular restrictions on the molecular structure of organopolysiloxanes, and they can have any shape, such as linear, branched, cyclic, network, or partially branched linear. Generally, linear molecular structures with such molecular structures are used, but are not limited to this.

[0099] (1) More specific examples of organopolysiloxanes may include: dimethylsiloxane-methylvinylsiloxane copolymers with trimethylsiloxane groups at both ends of the molecular chain; methylvinylpolysiloxanes with trimethylsiloxane groups at both ends of the molecular chain; dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers with trimethylsiloxane groups at both ends of the molecular chain; dimethylpolysiloxanes with dimethylvinylsiloxane groups at both ends of the molecular chain; methylvinylpolysiloxanes with dimethylvinylsiloxane groups at both ends of the molecular chain; dimethylsiloxane-methylvinylsiloxane copolymers with dimethylvinylsiloxane groups at both ends of the molecular chain; dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers with dimethylvinylsiloxane groups at both ends of the molecular chain; dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers with dimethylvinylsiloxane groups at both ends of the molecular chain; comprising R 1 2SiO 2 / 2 The siloxane unit represented by R and the siloxane unit represented by R 1 2R 2 SiO 1 / 2 The siloxane unit represented and the siloxane unit composed of SiO 4 / 2 The organopolysiloxane copolymer representing the siloxane unit comprises R 1 2R 2 SiO 1 / 2 The siloxane unit represented and the siloxane unit composed of SiO 4 / 2 The organopolysiloxane copolymer representing the siloxane unit comprises R 1 R 2 SiO 2 / 2 The siloxane unit represented by R and the siloxane unit represented by R 1 SiO 3 / 2 The siloxane unit represented by R or made of 2 SiO 3 / 2 The term refers to organopolysiloxane copolymers containing siloxane units, and mixtures of two or more of the aforementioned, but is not limited thereto. Here, R... 1 This refers to a hydrocarbon group other than an alkenyl group, specifically alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, or heptyl; aryl groups such as phenyl, tolyl, xylyl, or naphthyl; aralkyl groups such as benzyl or phenyl; halogen-substituted alkyl groups such as chloromethyl, 3-chloropropyl, or 3,3,3-trifluoropropyl; and so on. Furthermore, R... 2 It is an alkenyl group, which can specifically be vinyl, allyl, butenyl, pentenyl, hexenyl, or heptenyl, etc.

[0100] In an addition-curable organosilicon composition, (2) the organopolysiloxane can be used to crosslink (1) the organopolysiloxane. In (2) the organopolysiloxane, the bonding position of the hydrogen atoms is not particularly limited, and they can, for example, be bonded to the ends and / or side chains of the molecular chain. Furthermore, in (2) the organopolysiloxane, the types of substituents that may be included in addition to the hydrogen atoms bonded to silicon are not particularly limited, and may include, for example, alkyl, aryl, aralkyl, or halogen-substituted alkyl groups as mentioned in (1) the organopolysiloxane, and among these, methyl or phenyl is typically used, but not limited thereto.

[0101] (2) There are no particular restrictions on the molecular structure of organopolysiloxanes, and they can have any shape, such as linear, branched, cyclic, network, or partially branched linear. Generally, one of the linear molecular structures is used, but it is not limited to this.

[0102] (2) More specific examples of organopolysiloxanes may include: methylhydropolysiloxanes end-capped with trimethylsiloxane groups at both ends of the molecular chain; dimethylsiloxane-methylhydropolymers end-capped with trimethylsiloxane groups at both ends of the molecular chain; dimethylsiloxane-methylhydrosiloxane-methylphenylsiloxane copolymers end-capped with trimethylsiloxane groups at both ends of the molecular chain; dimethylpolysiloxanes end-capped with dimethylhydrosiloxane groups at both ends of the molecular chain; dimethylsiloxane-methylphenylsiloxane copolymers end-capped with dimethylhydrosiloxane groups at both ends of the molecular chain; and methylphenylpolysiloxanes end-capped with dimethylhydrosiloxane groups at both ends of the molecular chain, comprising R 1 3SiO 1 / 2 The siloxane unit represented by R 1 2HSiO 1 / 2 The siloxane unit represented and the siloxane unit composed of SiO 4 / 2 The organopolysiloxane copolymer representing the siloxane unit comprises R 1 2HSiO 1 / 2 The siloxane unit represented and the siloxane unit composed of SiO 4 / 2 The organopolysiloxane copolymer representing the siloxane unit comprises R 1 HSiO 2 / 2 The siloxane unit represented by R and the siloxane unit represented by R 1 SiO 3 / 2 The siloxane unit represented is or is composed of HSiO 3 / 2 The term refers to organopolysiloxane copolymers containing siloxane units, and mixtures of two or more of the aforementioned, but is not limited thereto. Here, R... 1It can be a hydrocarbon group other than an alkenyl group, specifically an alkyl group such as methyl, ethyl, propyl, butyl, pentyl, hexyl or heptyl; an aryl group such as phenyl, tolyl, xylyl or naphthyl; an aralkyl group such as benzyl or phenyl; a halogen-substituted alkyl group such as chloromethyl, 3-chloropropyl or 3,3,3-trifluoropropyl; and so on.

[0103] (2) There is no particular limitation on the content of the organopolysiloxane, as long as it is contained to a degree that allows for suitable curing. For example, (2) the organopolysiloxane may be contained in an amount of 0.5 to 10 hydrogen atoms of bonded silicon per alkenyl group contained in (1) the organopolysiloxane as described above. Within such a range, sufficient curing can be achieved and heat resistance can be ensured.

[0104] Addition-curable silicone compositions may also contain platinum or platinum compounds as catalysts for curing. There are no particular limitations on the specific type of platinum or platinum compound. The catalyst ratio can also be adjusted to a level suitable for proper curing.

[0105] In addition, the addition-curable silicone composition may also contain suitable additives in appropriate proportions as needed from the viewpoint of improving storage stability, handling properties and processability.

[0106] In another example, as a condensable curable silicone composition, the silicone composition may comprise, for example, (a) an alkoxy-containing siloxane polymer; and (b) a hydroxyl-containing siloxane polymer.

[0107] (a) The siloxane polymer can be, for example, a compound represented by Formula 1 below.

[0108] [Formula 1]

[0109] R 1 a R 2 b SiO c (OR 3 ) d

[0110] In Equation 1, R 1 and R 2 Each independently represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R 3 Represents an alkyl group, wherein when a plurality of R are present... 1 R 2 and R 3 When, they can be the same or different from each other, and a and b can each independently represent a number that is 0 or greater than and less than 1, a+b represents a number that is greater than 0 and less than 2, c represents a number that is greater than 0 and less than 2, d represents a number that is greater than 0 and less than 4, and a+b+c×2+d equals 4.

[0111] In the definition of Formula 1, the monovalent hydrocarbon group can be, for example, an alkyl, phenyl, benzyl, or tolyl group having 1 to 8 carbon atoms, wherein the alkyl group having 1 to 8 carbon atoms can be methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, heptyl, or octyl, etc. Furthermore, in the definition of Formula 1, the monovalent hydrocarbon group can be substituted with known substituents such as halogen, amino, mercapto, isocyanate, glycidyl, glycidoxy, or urea.

[0112] Under the constraints of Equation 1, R 3 Examples of alkyl groups may include methyl, ethyl, propyl, isopropyl, or butyl, etc. Among these alkyl groups, methyl or ethyl are commonly used, but are not limited to these.

[0113] In the polymer of Formula 1, branched or tertiary crosslinked siloxane polymers can be used. Furthermore, in this (a) siloxane polymer, hydroxyl groups can be retained to a extent that does not impair the purpose (specifically, to a extent that does not inhibit the dealcoholization reaction).

[0114] (a) Siloxane polymers can be produced, for example, by hydrolyzing and condensing polyfunctional alkoxysilanes or polyfunctional chlorosilanes. Those skilled in the art can readily select suitable polyfunctional alkoxysilanes or chlorosilanes according to the desired (a) siloxane polymer, and can also use them to easily control the conditions of the hydrolysis and condensation reactions. Furthermore, in the production of (a) siloxane polymers, suitable monofunctional alkoxysilanes can also be used in combination, depending on the purpose.

[0115] As (a) a siloxane polymer, for example, commercially available organosiloxane polymers such as Shin-EtsuSilicone's X40-9220 or X40-9225, or GE Toray Silicone's XR31-B1410, XR31-B0270, or XR31-B2733 can be used.

[0116] As a hydroxyl-containing siloxane polymer included in a condensable curable organosilicon composition, for example, a compound represented by the following formula (2) can be used.

[0117] [Equation 2]

[0118]

[0119] In Equation 2, R 4 and R 5 Each independently represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, wherein when there are multiple R... 4 and R 5 They can be the same or different from each other, and n represents an integer from 5 to 2,000.

[0120] In the definition of Formula 2, the specific type of monovalent hydrocarbon group may include, for example, the same hydrocarbon group as in Formula 1 above.

[0121] (b) Siloxane polymers can be produced, for example, by hydrolyzing and condensing dialkoxysilanes and / or dichlorosilanes. Those skilled in the art can readily select suitable dialkoxysilanes or dichlorosilanes according to the desired (b) siloxane polymer, and can also use them to readily control the conditions of the hydrolysis and condensation reactions. As the above-mentioned (b) siloxane polymers, commercially available bifunctional organosiloxane polymers can be used, such as GE Toray Silicone's XC96-723, YF-3800, or YF-3804, etc.

[0122] The above-described addition-curable or condensation-curable silicone compositions are examples of materials used to form the silicone pressure-sensitive adhesives or binders used in this application. In essence, all silicone pressure-sensitive adhesives or binders industrially known as OCA or OCR, etc., can be used in this application.

[0123] There are no particular limitations on the type of pressure-sensitive adhesive or binder or curable composition forming therefrom, which may be appropriately selected according to the intended use. For example, solid, semi-solid, or liquid pressure-sensitive adhesives or binders or curable compositions may be used. Solid or semi-solid pressure-sensitive adhesives or binders or curable compositions may cure before the bonded (or cohesive) objects are bonded. Liquid pressure-sensitive adhesives or binders or curable compositions are referred to as so-called optically clear resins (OCR), which may cure after the bonded or cohesive objects are bonded. According to one example, pressure-sensitive adhesives or binders or curable compositions may be used as so-called polydimethylsiloxane-based pressure-sensitive adhesives or binders or curable compositions, or polymethylvinylsiloxane-based pressure-sensitive adhesives or binders or curable compositions, or alkoxysilicone-based pressure-sensitive adhesives or binders or curable compositions, and are not limited thereto.

[0124] There are no particular limitations on the thickness of the pressure-sensitive adhesive layer or adhesive layer; it can be selected within a suitable range to ensure the desired adhesive or cohesive strength. The thickness can range from about 1 μm to 50 μm. In another example, the thickness can be 2 μm or greater, 3 μm or greater, 4 μm or greater, 5 μm or greater, 6 μm or greater, 7 μm or greater, 8 μm or greater, 9 μm or greater, or 10 μm or greater, or it can also be about 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 15 μm or less, or about 10 μm or less.

[0125] By including such an adhesive layer or pressure-sensitive adhesive layer in such an arrangement, a light modulation device can be provided that exhibits excellent optical properties while having excellent adhesion (or cohesion) and light leakage can be controlled (especially in black mode).

[0126] By combining the orientation of a liquid crystal compound formed from a known vertical alignment film and an adhesive or pressure-sensitive adhesive that has vertical alignment capability, and / or the aforementioned -C plate, side light leakage can be effectively suppressed when the liquid crystal compound is vertically aligned, and front light absorption can be minimized when it is horizontally aligned.

[0127] In one example of this application, when an adhesive layer or pressure-sensitive adhesive layer with vertical orientation force is formed on one side of the first polymer film substrate, a liquid crystal alignment film may not be formed on the first polymer film substrate.

[0128] The optical modulation device of this application may further include a conductive layer on one side of each of the first polymer film substrate and the second polymer film substrate, as long as it does not impair the effect of this application. For example, the conductive layer may be formed between the adhesive layer or pressure-sensitive adhesive and the first polymer film substrate, and between the liquid crystal alignment film and the second polymer film substrate. When a conductive layer is formed, the -C plate may be disposed between the first polymer film substrate and the conductive layer, or between the conductive layer and the pressure-sensitive adhesive layer (or adhesive layer), or between the pressure-sensitive adhesive layer (or adhesive layer) and the optical modulation layer, and / or may be disposed between the second polymer film substrate and the conductive layer, between the conductive layer and the liquid crystal alignment film, or between the liquid crystal alignment film and the optical modulation layer.

[0129] In one example, the optical modulation device of this application may represent a structure including the following: a first substrate 100 wherein a first polarizing layer 101, a first polymer film substrate 102, a conductive layer 400a, a -C plate 600, and an adhesive layer or pressure-sensitive adhesive layer 103 are sequentially formed; an optical modulation layer 300; and a second substrate 200 wherein a liquid crystal alignment film 203, a conductive layer 400b, a second polymer film substrate 202, and a second polarizing layer 201 are sequentially formed, such as... Figure 5 As shown, or -C plate 600 may be disposed, for example, between the first polymer film substrate 102 and the conductive layer 400a, or between the second polymer film substrate 202 and the conductive layer 400b, but is not limited thereto.

[0130] The conductive layer can transmit a suitable electric field to the light modulation layer to switch the orientation of the liquid crystal compound in the light modulation layer. The direction of the electric field can be vertical or horizontal, such as the thickness direction or planar direction of the light modulation layer.

[0131] The conductive layer can be, for example, a transparent conductive layer, and can be formed by depositing, for example, conductive polymers, conductive metals, conductive nanowires, or metal oxides such as ITO (indium tin oxide). Furthermore, various materials and methods for forming transparent conductive layers are known and can be used without limitation.

[0132] Such light modulation devices can be applied to a variety of applications. Examples of suitable applications include openings in enclosed spaces such as buildings, containers, or vehicles (e.g., windows or skylights), eye-wearing devices, windows and doors, and light-blocking panels for OLEDs (organic light-emitting devices). Within the scope of eye-wearing devices, this includes all eye-wearing devices configured to allow an observer to see the outside world through lenses, such as ordinary glasses, sunglasses, sports goggles or helmets, or wearable devices such as those used for experiencing virtual reality or augmented reality.

[0133] Typical applications of the optical modulation device of this application may include vehicle sunroofs.

[0134] In one instance, the light modulation device itself can be a vehicle sunroof. For example, in a vehicle body that includes at least one or more openings, a light modulation device or a vehicle sunroof mounted on the openings can be installed and used.

[0135] A sunroof is a fixed or operable (ventilated or sliding) opening on the roof of a vehicle, and can be generally referred to as any device that allows light or fresh air to enter the interior of the vehicle. In this application, there are no particular limitations on the method of operating the sunroof; for example, it can be manually operated or electrically driven, and the shape, size, or style of the sunroof can be appropriately selected according to its intended use. For example, depending on the method of operation, a sunroof can be exemplified as a pop-up sunroof, a spoiler (flat and sliding) sunroof, a built-in sunroof, a folding sunroof, a roof-mounted sunroof, a panoramic sunroof system sunroof, a removable roof panel (T-roof or Targa roof) sunroof, or a solar sunroof, etc., but is not limited to these.

[0136] The exemplary skylight of this application may include the light modulation device of this application, and in this case, for the details of the light modulation device, the content described in the project of the light modulation device can be applied equivalently.

[0137] Beneficial effects

[0138] This application relates to an optical modulation device. This application can provide an optical modulation device that possesses excellent optical characteristics, including variable transmittance, through the characteristic control and appropriate arrangement of a compensation film, and is suitable for various applications by controlling tilt angle light leakage in black mode. Attached Figure Description

[0139] Figures 1 to 5 This is a schematic diagram of an exemplary optical modulation device of this application.

[0140] Figure 6 This is a schematic diagram used to explain the tilt angle and radial angle.

[0141] Figure 7 A diagram illustrating a method for evaluating refractive index anisotropy.

[0142] Figures 8 to 11 A graph showing the results of measuring the frontal transmittance and tilt angle transmittance of the light modulation apparatus in the black mode of Examples 1 to 4.

[0143] Figure 12 and Figure 13 A graph showing the results of measuring the frontal transmittance and tilt angle transmittance of the light modulation devices of Comparative Example 1 and Comparative Example 2 in black mode. Detailed Implementation

[0144] The present application will be described in detail below by way of embodiments, but the scope of the present application is not limited to the following embodiments.

[0145] Evaluation Example 1. Measurement of maximum transmittance at tilt angles (including front view) in black mode.

[0146] Transmittance at an angle (including the front) in black mode (without applied voltage, 0V) was measured using a haze meter (NDH5000SP, Sekos) according to ASTM D1003 standard.

[0147] Specifically, when light with wavelengths from 380 nm to 780 nm is incident on the object being measured within the integrating sphere, the incident light is split into diffuse light (DT, the sum of all diffuse and emitted light) and linear light (PT, light emitted from the front excluding diffuse light) by the object. The diffuse and linear light can each be measured by focusing them onto a light-receiving element within the integrating sphere. That is, using the above method, the total transmitted light (TT) is defined as the sum of the diffused light (DT) and the linear light (PT) (DT + PT). Total transmitted light refers to the total transmittance.

[0148] The maximum value of the transmittance at the tilt angle (including the front side) of the light modulation apparatus in black mode (0V) of the embodiments and comparative examples was set to the maximum value among the values ​​obtained by measuring the omnidirectional transmittance with respect to the front side and the tilt angle without applying voltage to the light modulation apparatus. The z-axis direction, which is the normal direction of the reference plane used as the measurement object (e.g., the reference plane can be the surface of the polarizing layer, polymer film substrate, light modulation layer, -C plate, adhesive layer (or pressure-sensitive adhesive layer), or liquid crystal alignment film, etc. in the light modulation apparatus), was set to 0 degrees, and values ​​were set to -60 degrees, -45 degrees, -30 degrees, -15 degrees, 0 degrees (front side), 15 degrees, 30 degrees, 45 degrees, and 60 degrees (front side). Figure 6 Each of the tilt angles Θ in the equation will be... Figure 6 When the radial angle Φ is changed to 0 degrees, 30 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees, 180 degrees, 210 degrees, 240 degrees, 270 degrees, 300 degrees, and 330 degrees, the measurement results will be displayed in... Figures 8 to 11 The figures are described in the table (the horizontal axis refers to the radial angle Φ, the vertical axis refers to the transmittance (%), and the lines in each figure indicate the values ​​measured at a specific tilt angle Θ), and the maximum values ​​are shown in Table 1.

[0149] Evaluation Example 2: Assessment of Planar Phase Difference of Polymer Membrane Substrate

[0150] The planar phase difference (Rin) of the polymer film (based on a wavelength of 550 nm) was measured using an Agilent UV / VIS beam splitter 8453. Two polarizers were mounted in the UV / VIS beam splitter with their transmission axes orthogonal to each other. The polymer film was positioned between the two polarizers such that its slow axis forms a 45-degree angle with the transmission axes of each polarizer, and the transmittance was measured according to the wavelength. The phase retardation order of each peak was obtained from the transmittance plot according to the wavelength. Specifically, the waveforms in the transmittance plot according to the wavelength satisfy Equation A, and the maximum peak (Tmax) condition in the sine waveform satisfies Equation B. In the case of λmax in Equation A, since T in Equation A is the same as T in Equation B, the equations are expanded. Since the equations are also expanded for n+1, n+2, and n+3, the equations for n and n+1 are rearranged to eliminate R, and n is rearranged into equations λn and λn+1, thus deriving Equation C. Since n and λ are known based on the fact that T in equation A is the same as T in equation B, R is obtained for each of λn, λn+1, λn+2, and λn+3. A linear trend line for the R values ​​based on the wavelengths at the four points is obtained, and the R value for 550 nm is calculated. The function of the linear trend line is Y = ax + b, where a and b are constants. The value of Y when x in the function is replaced by 550 nm is the Rin value for light with a wavelength of 550 nm.

[0151] [Equation A]

[0152] T = sin2[(2πR / λ)]

[0153] [Equation B]

[0154] T = sin2[((2n+1)π / 2)]

[0155] [Equation C]

[0156] n=(λn-3λn+1) / (2λn+1+1-2λn)

[0157] Here, R refers to the plane phase difference (Rin), λ refers to the wavelength, and n refers to the nodal degree of the sine wave.

[0158] Evaluation Example 3. Thickness of the optical modulation layer

[0159] The thickness of the optical modulation layer is the same as the height of the spacer, and the height of the spacer is determined using a measuring device (Optical Profiler, Nano System, Nano View-E1000).

[0160] Evaluation Example 4. Evaluation of the refractive index anisotropy and average refractive index of the optical modulation layer (liquid crystal layer) or -C plate.

[0161] The refractive index anisotropy (Δn) and mean refractive index of the light modulation layer or -C plate are evaluated using an Abbe refractometer in the following manner. In the case of the light modulation layer, the liquid crystal compound to be measured is vertically oriented by a vertical orientation force by coating a perpendicular alignment film onto the measuring prism surface and the illumination prism surface of the Abbe refractometer, coating the measuring prism with the liquid crystal compound to be measured, and then covering it with the illumination prism. In this process, the liquid crystal compound applied is only the liquid crystal compound applied to the light modulation layer and is not mixed with other materials such as dichroic dyes. Furthermore, in the case of the -C plate, it is measured by applying or attaching the -C plate material to the measuring prism surface and the illumination prism surface of the Abbe refractometer, and then covering it with the illumination prism.

[0162] Then, as Figure 7 As shown, when a linear polarizer is applied to the eyepiece side (the matte side) and the light to be observed is used for illumination, the following can be obtained: Figure 7 θ shown e and θ o And it can be determined by measuring the refractive index (n) of the prism. p ) and angle (θ) e and θ o Obtaining unusual refractive index (n) e =n p sinθe ) and ordinary refractive index (n o =n p sinθ o Here, the difference (n) can be... e -n o ) is defined as refractive index anisotropy, and the average value ((n) can be expressed as anisotropy. e +n o () / 2) is defined as the average refractive index. The reference wavelength for measurement is approximately 550 nm.

[0163] Example 1.

[0164] The device is manufactured using a stretched PET (polyethylene terephthalate) film substrate (thickness: 145 μm, manufacturer: SKC) as both the first and second polymer film substrates. The PET film substrate has a planar phase difference of approximately 10,000 nm to 15,000 nm for light with a wavelength of 550 nm.

[0165] First, an ITO (indium tin oxide) film (conductive layer) is deposited on one side of a first PET film substrate. Then, a -C plate material rod is coated onto the ITO film, and the substrate is cured at approximately 100°C for 20 minutes to form a -C plate with a thickness of approximately 6 μm. The -C plate has a thickness-direction phase difference of approximately -720 nm for light with a wavelength of 550 nm, and an average refractive index of 1.65. Here, the -C plate material is prepared by blending a polyamide in which terephthalic acid, isophthalic acid, and 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine are polymerized at a ratio of approximately 5.3% by weight relative to a dimethylacetamide solution.

[0166] Subsequently, a silicone pressure-sensitive adhesive (Shinetsu, KR3700) stick was applied to the -C plate and then cured at approximately 100°C for 100 minutes to form a pressure-sensitive adhesive layer (first substrate) with a thickness of approximately 10 μm.

[0167] First, an ITO (indium tin oxide) film (conductive layer) is deposited on one side of the second PET film substrate. Spacers in the form of square dividers (pitch: 350 μm, height: 8 μm, linewidth: 16 μm, area ratio: 9%) are formed on the ITO film to maintain the cell gaps. Next, a polyimide-based vertical alignment film (SE-5661LB3, Nissan) with a thickness of approximately 100 nm is formed for initial alignment control of the light modulation layer (liquid crystal layer), and then subjected to rubbing with a rubbing cloth. At this time, the rubbing direction is set to be horizontal with the slow axis of the lower PET film substrate (second substrate).

[0168] Subsequently, the pressure-sensitive adhesive layer of the first substrate and the alignment film of the second substrate are arranged facing each other (cell spacing: 8 μm), and liquid crystal material is injected therein. The apparatus is then manufactured through a lamination process. As the liquid crystal material, a composition is used that mixes a chiral dopant (S811, Merck) with a liquid crystal compound (SHN-7002XX T12, JNC) having a negative dielectric constant anisotropy with a refractive index anisotropy (Δn) of approximately 0.094 and an average refractive index of 1.58. At this time, approximately 0.5 parts by weight of the chiral dopant are mixed with 100 parts by weight of the liquid crystal compound, resulting in a chiral spacing of approximately 20 μm. Furthermore, the resulting light modulation layer has a thickness-direction phase difference of approximately 752 nm for light with a wavelength of 550 nm.

[0169] Subsequently, a first polarizing layer is attached to the surface of a first PET film substrate on which an ITO film (conductive layer) is not formed, and a second polarizing layer is attached to the surface of a second PET film substrate on which an ITO film (conductive layer) is not formed. As the first and second polarizing layers, ordinary PVA polarizing layers prepared by adsorbing iodine onto a PVA film via high temperature / stretching are used.

[0170] The arrangement is such that the slow axis directions of the first and second polymer film substrates and the absorption axis of the first polarizing layer are parallel to each other, and the absorption axis of the second polarizing layer is perpendicular to the absorption axis of the first polarizing layer.

[0171] Therefore, an optical modulation device is formed having a structure of a first polarizing layer / a first PET film substrate / ITO film / -C plate / adhesive layer / optical modulation layer (liquid crystal layer) / alignment film / ITO film / second PET film substrate / second polarizing layer.

[0172] Example 2

[0173] The light modulation device is manufactured in the same manner as in Example 1, except that during the production of the first substrate, the -C plate, ITO film, and adhesive layer are sequentially formed on one side of the first PET film substrate. Therefore, a light modulation device is formed having a structure of first polarizing layer / first PET film substrate / -C plate / ITO film / adhesive layer / light modulation layer (liquid crystal layer) / alignment film / ITO film / second PET film substrate / second polarizing layer.

[0174] Example 3

[0175] The light modulation device is manufactured in the same manner as in Example 1, except that the -C plate is not formed between the ITO film and the adhesive layer of the first substrate, but rather between the second polymer substrate and the ITO film of the second substrate. Therefore, a light modulation device is formed having a structure of first polarizing layer / first PET film substrate / ITO film / adhesive layer / light modulation layer (liquid crystal layer) / alignment film / ITO film / -C plate / second PET film substrate / second polarizing layer.

[0176] Example 4

[0177] The light modulation device is manufactured in the same manner as in Example 2, except that when the pressure-sensitive adhesive layer of the first substrate and the alignment film of the second substrate are arranged to face each other, they are arranged such that the unit gap is 6 μm (the height of the spacer is also 6 μm), the phase difference in the thickness direction of the light modulation layer with respect to light with a wavelength of 550 nm is about 564 nm, and the phase difference in the thickness direction of the -C plate with respect to light with a wavelength of 550 nm is about -540 nm. Therefore, a light modulation device is formed having a structure of a first polarizing layer / first PET film substrate / -C plate / ITO film / adhesive layer / light modulation layer (liquid crystal layer) / alignment film / ITO film / second PET film substrate / second polarizing layer.

[0178] Comparative Example 1.

[0179] The optical modulation device is manufactured in the same manner as in Example 1, except that the -C plate is not introduced.

[0180] Therefore, an optical modulation device is formed having a structure of a first polarizing layer / a first PET film substrate / ITO film / adhesive layer / optical modulation layer (liquid crystal layer) / alignment film / ITO film / second PET film substrate / second polarizing layer.

[0181] Compare Example 2.

[0182] The light modulation device is manufactured in the same manner as in Example 1, except that the -C plate is disposed between the first polarizing layer and the first PET film substrate.

[0183] Therefore, an optical modulation device is formed having a structure of a first polarizing layer / -C plate / first PET film substrate / ITO film / adhesive layer / light modulation layer (liquid crystal layer) / alignment film / ITO film / second PET film substrate / second polarizing layer.

[0184] [Table 1]

[0185] Classification Maximum transmittance at tilt angle (front) in black mode (0V) Example 1 6.92％ Example 2 6.34％ Example 3 6.61％ Example 4 5.22％ Comparative Example 1 17.27％ Comparative Example 2 14.32％

[0186] In Table 1 above, the maximum transmittance at tilt angles (including front view) in black mode (0V) represents the maximum transmittance value measured when: the z-axis direction of the normal direction of the reference plane of the object being measured (e.g., the reference plane can be the surface of a polarizing layer, polymer film substrate, light modulation layer, -C plate, adhesive layer (or pressure-sensitive adhesive layer), or liquid crystal alignment film, etc. in an optical modulation device) is set to 0 degrees, and for -60 degrees, -45 degrees, -30 degrees, -15 degrees, 0 degrees (front view), 15 degrees, 30 degrees, 45 degrees, and 60 degrees (front view). Figure 6 Each of the tilt angles Θ in the equation will be... Figure 6 The radial angle Φ is changed to 0 degrees, 30 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees, 180 degrees, 210 degrees, 240 degrees, 270 degrees, 300 degrees, and 330 degrees. Therefore, it can be determined that the tilt angle (including the front) light leakage of the optical modulation devices of Examples 1 to 4 is less than that of the tilt angle (including the front) light leakage of the optical modulation devices of Comparative Examples 1 and 2.

[0187] [Explanation of reference numerals in the attached figures]

[0188] 100, 200: First basement, Second basement

[0189] 101, 201: First polarizing layer and second polarizing layer

[0190] 102, 202: First polymer membrane substrate and second polymer membrane substrate

[0191] 103: Adhesive layer or pressure-sensitive adhesive layer

[0192] 203: Liquid crystal alignment film

[0193] 300: Optical Modulation Layer

[0194] 400a, 400b: Conductive layers

[0195] 500: Spacer

[0196] 600: -C board

[0197] G: Unit gap

Claims

1. An optical modulation device comprising: a first polymer film substrate having an adhesive layer or a pressure-sensitive adhesive layer formed on a first surface of the first polymer film substrate; a second polymer film substrate having a liquid crystal alignment film formed on a first surface of the second polymer film substrate; a light modulation layer containing a liquid crystal compound; a first polarizing layer attached to a second surface of the first polymer film substrate, and a second polarizing layer attached to a second surface of the second polymer film substrate, wherein wherein the absorption axes of the first polarizing layer and the second polarizing layer are perpendicular to each other, the first polymer film substrate and the second polymer film substrate are disposed such that their first surfaces face each other, the light modulation layer is present between the oppositely disposed first polymer film substrate and second polymer film substrate, and a -C plate is included in at least one position between the light modulation layer and the first polymer film substrate or between the light modulation layer and the second polymer film substrate, wherein the adhesive layer or pressure-sensitive adhesive layer has a vertical alignment force to liquid crystal molecules, and a liquid crystal alignment film is not formed on the first polymer film substrate, wherein the -C plate is present between the pressure-sensitive adhesive layer or adhesive layer and the first polymer film substrate or between the liquid crystal alignment film and the second polymer film substrate, wherein the -C plate means a layer satisfying a refractive index relationship of nx = ny > nz or nx > ny > nz, where nx is a refractive index of a layer in a slow axis direction, ny is a refractive index in a fast axis direction, and nz is a refractive index in a normal direction of a plane formed by the slow axis and the fast axis, wherein each of the first polymer film substrate and the second polymer film substrate has a planar phase difference of 500 nm or more for a wavelength of 550 nm, wherein the liquid crystal alignment film is a vertical alignment film, and the alignment of the liquid crystal compound is formed by the vertical alignment film and an adhesive or pressure-sensitive adhesive having a vertical alignment capability, wherein the spacing between the first polymer film substrate and the second polymer film substrate is maintained by a spacer having a partition shape, wherein the slow axes of the first polymer film substrate and the second polymer film substrate are horizontal to each other, and the slow axes of the first polymer film substrate and the second polymer film substrate are perpendicular or horizontal to the absorption axes of the first polarizing layer and the second polarizing layer, wherein the -C plate has an absolute value C of a thickness direction phase difference satisfying the following Condition 1, and the thickness direction phase difference of the -C plate is a negative value: [Condition 1] C ≤ D x 1.2 wherein D is a value determined by a thickness direction phase difference of the light modulation layer in a vertical alignment state x (an average refractive index of the liquid crystal compound contained in the light modulation layer / an average refractive index of the -C plate).

2. The light modulation device according to claim 1, wherein the spacer has a shape of a quadrangular, triangular, or honeycomb partition.

3. The light modulation device according to claim 1, wherein the spacer contains a curable resin.

4. The light modulating device according to claim 1, wherein the initial alignment of the liquid crystal compound in the light modulating layer is homeotropic alignment.

5. The light modulating device according to claim 4, wherein the state of the homeotropic alignment is changeable to a state of horizontal alignment by applying an external signal.

6. The light modulating device according to claim 1, wherein the light modulating layer further comprises a chiral dopant.

7. The light modulating device according to claim 6, wherein the ratio of the thickness d of the light modulating layer to the chiral pitch p formed by the chiral dopant d / p is less than 1.

8. The light modulating device according to claim 1, wherein the pressure sensitive adhesive of the pressure sensitive adhesive layer or the adhesive of the adhesive layer is a silicone pressure sensitive adhesive or a silicone adhesive.

9. The light modulating device according to claim 1, wherein an electrically conductive layer is formed between the adhesive layer or the pressure sensitive adhesive layer and the first polymeric film substrate and between the liquid crystal alignment film and the second polymeric film substrate, respectively.

10. A vehicle comprising a vehicle body having one or more openings formed therein; and the light modulating device according to claim 1 mounted on the opening.

Images