KR20190052829A - Optical Device - Google Patents

Abstract

The present application relates to a light quantity adjusting device. According to one embodiment of the present application, provided is a light quantity adjusting device in which a difference in transmittance between a blocking state and a transmission state is large, and a desired transmittance level such as an intermediate transmittance level can be freely adjusted, thereby being capable of quickly taking the speed of a transmission variation.

Description

[0001]

The present application relates to a light amount adjusting apparatus.

There are a variety of devices known as devices for controlling the amount of light. For example, a transmittance variable device using a so-called GH cell (Guest host cell), in which a mixture of a liquid crystal host, which is mainly a liquid crystal compound, and a dichroic dye guest, is known Document 1). However, the apparatus does not have a large range of variable transmittance, so that the difference between the transmissivity in the blocking state and the transmissivity in the transmissive state is not large.

As another light quantity control device, a device using a so-called photochromic layer is also known. The transmittance of the photochromic layer varies depending on the amount of ultraviolet light to be irradiated. Such a device has a variable transmittance, but has a different coloring speed depending on the intensity of the ultraviolet light to be irradiated, and the transmittance variable speed is very slow overall.

European Patent No. 0022311

The present application aims at providing a light amount adjusting apparatus. In one example, the present application is to provide a light amount adjusting device capable of freely adjusting a desired transmittance level, such as a medium-level transmittance and a transmittance difference in a blocking state and a transmissive state, .

The present application relates to a light amount adjusting apparatus. The light amount control apparatus of the present application can form a variable transmittance device, alone or in combination with other elements. The term transmittance variable device may mean a device designed to switch between a state of high transmittance and a state of low transmittance. The transmittance variable device may optionally implement a desired transmittance at an intermediate level between the high transmittance state and the low transmittance state, if necessary.

In this specification, the high transmittance state can be referred to as a transmission state, and the low transmittance state can be referred to as a blocking state.

The transmission state may mean, for example, a state where the transmittance of the apparatus is 40% or more, and the cutoff state may mean a state where the transmittance of the apparatus is 10% or less. The transmittance in the transmissive state is the highest transmittance that can be achieved by the light quantity control device or the transmittance variable device and the transmittance in the cutoff state is the transmittance in the lowest state that can be realized by the light quantity control device or the transmittance variable device Transmittance. In the present specification, the transmittance is a transmittance for visible light, and is, for example, any wavelength within a range of about 400 to 700 nm, or an average transmittance in the whole wavelength range or a wavelength range It may be the transmittance at the highest or lowest transmittance wavelength. In one example, the transmittance in the transmissive state can be about 45% or more, 50% or more, 55% or more, 60% or more, or 65% or more. Further, the transmittance in the blocking state may be about 9% or less, 8% or less, 7% or less, 6% or 5.5% or less in another example.

The higher the numerical value is, the better the transmittance in the transparent state is, and the lower the transmittance in the blocking state is, the better the upper and lower limits are not particularly limited. In one example, the upper limit of the transmittance in the transmissive state may be about 100%, about 95%, about 90%, about 85%, about 80%, about 75%, or about 70%. The lower limit of the transmittance in the blocking state may be about 0%, about 1%, about 2%, about 3%, about 4%, or about 5%.

The transmittance may be a linear light transmittance. The term linear light transmittance may be a ratio of the light (straight light) transmitted through the device in the same direction as the incident direction to the light incident on the light amount regulator or the transmittance variable device in a predetermined direction. In one example, the transmittance may be a result (normal linear light transmittance) measured with respect to light incident in a direction parallel to the surface normal of the device, or may be an angle that is greater than 0 degrees and less than 20 degrees with the surface normal (Oblique light transmittance) measured with respect to the light incident in the direction of the optical axis. The angle of incidence of the incident light with respect to the surface normal for the measurement of the oblique light transmittance may be about 0.5 degree or more, about 1 degree or more, or about 1.5 degree or more, about 19.5 degrees or less, about 19 degrees or less, About 18.5 degrees, about 17 degrees, about 17 degrees, about 16.5 degrees, about 16 degrees, about 15.5 degrees, about 15 degrees, about 14.5 degrees, about 14 degrees, about About 13.5 degrees, about 13.5 degrees, about 12.5 degrees, about 12 degrees, about 11.5 degrees, about 11 degrees, about 10.5 degrees, about 10 degrees, about 9.5 degrees, about 9 degrees, about About 8 degrees or less, about 7.5 degrees or less, about 7 degrees or less, about 6.5 degrees or less, about 6 degrees or less, about 5.5 degrees or less, about 5 degrees or less, about 4.5 degrees or less, Can be less than 3.5 degrees or less than about 3 degrees

The light amount control apparatus of the present application includes an active liquid crystal element, and the active liquid crystal element includes at least an active liquid crystal layer. In one example, the active liquid crystal layer may be an active guest host liquid crystal layer (hereinafter, referred to as an active GH layer). The active GH layer may be a liquid crystal compound (liquid crystal host), a liquid crystal compound (liquid crystal host), or the like. The active liquid crystal layer is a liquid crystal layer containing at least a liquid crystal compound and capable of changing the direction of the optical axis of the liquid crystal by an external signal, And a dichroic dye guest, and can also mean a liquid crystal layer formed so that the direction of the optical axis can be changed by an external signal, for example, a voltage.

Hereinafter, the active liquid crystal layer will be described as an active GH layer for the sake of convenience. However, the active GH layer may be applied to the active liquid crystal layer other than that the dichroic dye guest is not included.

In this case, the optical axis means an optical axis or a slow axis of a liquid crystal compound of the active liquid crystal layer or the GH layer, and the direction of the major axis when the liquid crystal compound is a rod, In the case of a discotic liquid crystal, it may mean an axis parallel to the normal direction of the disc plane.

The orientation of the dichroic dye contained in the GH layer is determined by the liquid crystal compound by a mechanism known as the so-called guest host effect.

The optical axis of the active GH layer is formed by a group consisting of a vertical alignment state, a horizontally aligned state, a twisted nematic (TN) aligned state, a super twisted nematic (STN) aligned state, a splay aligned state and a cholesteric aligned state May be formed so as to be able to switch between two or more states selected from among the plurality of states.

The vertical alignment state is a state in which the optical axis or the average optical axis of the active liquid crystal layer or the GH layer is within a range of -10 degrees to -10 degrees, -8 degrees to 8 degrees, and -6 degrees to the normal direction of the plane of the GH layer, Means an angle within a range of -4 degrees to 4 degrees, an angle within a range of -2 degrees to 2 degrees, or substantially parallel to each other. The horizontal alignment state is a state in which the optical axis or the average optical axis of the active liquid crystal layer or the GH layer is within a range of approximately -10 degrees to 10 degrees from the direction perpendicular to the normal direction of the liquid crystal layer or the GH layer, Means an angle within a range of -6 to 6 degrees, a range of -4 to 4 degrees, a range of -2 to 2 degrees, or substantially parallel.

The average optical axis may be the vector sum of the optical axes of the liquid crystal compound of the active liquid crystal layer or the GH layer.

The specific optical axis alignment state of the twisted nematic (TN) orientation state, the super twist nematic (STN) orientation, the splay orientation state, or the cholesteric orientation state among the above alignment states is well known in the art.

In one example, the active liquid crystal layer or the GH layer of the light amount control device exists in any one of the above-mentioned oriented states (initial alignment state) without external signals such as a voltage applied thereto, The organic electroluminescent device may be switched to an alignment state different from the initial alignment state, and may be switched to an initial alignment state when an external signal is lost. Further, it is also possible to switch between at least three alignment states among the alignment states by adjusting the intensity of an applied signal.

In this state, the thickness of the GH layer, that is, the cell gap may be about 1 탆 or more. The larger the thickness of the GH layer is, the more the difference between the minimum transmittance band and the maximum transmittance can be realized, so that the upper limit of the cell gap is not particularly limited.

The cell gap may be at least about 2 탆, at least about 3 탆, at least about 4 탆, at least about 5 탆, at least about 6 탆, at least about 7 탆, at least about 8 탆, at least about 9 탆, at least about 10 탆, 30 μm or less, 29 μm or less, 28 μm or less, 27 μm or less, 26 μm or less, 25 μm or less, 24 μm or less, 23 μm or less, 21 mu m or less, 20 mu m or less, 19 mu m or less, 18 mu m or less, 17 mu m or less, 16 mu m or less, or 16.5 mu m or less.

The kind of the liquid crystal compound contained in the active GH layer in the present application is not limited, and a known liquid crystal compound known to be capable of forming a GH cell can be applied. For example, a nematic liquid crystal compound can be used as the liquid crystal compound. The liquid crystal compound may be a non-reactive liquid crystal compound. The non-reactive liquid crystal compound may mean a liquid crystal compound having no polymerizable group. Examples of the polymerizable group include acryloyl groups, acryloyloxy groups, methacryloyl groups, methacryloyloxy groups, carboxyl groups, hydroxyl groups, vinyl groups, and epoxy groups, but not limited thereto, May be included.

The liquid crystal compound contained in the GH layer may have a positive dielectric anisotropy or a negative dielectric anisotropy. The term " dielectric anisotropy " in the present application can mean a difference between an ideal dielectric constant (epsilon e, extraordinary dielectric anisotropy) and a normal dielectric anisotropy (dielectric constant in short axis direction). The dielectric anisotropy of the liquid crystal compound may be within ± 40, within ± 30, within ± 10, within ± 7, within ± 5 or within ± 3, for example. Adjusting the dielectric anisotropy of the liquid crystal compound within the above range may be advantageous in terms of driving efficiency of the liquid crystal device.

The refractive index anisotropy of the liquid crystal compound present in the GH layer can be appropriately selected in consideration of the object physical properties, for example, the transmission characteristics, the contrast ratio, and the like. The term " refractive index anisotropy " may mean a difference between an extraordinary refractive index and an ordinary refractive index of a liquid crystal compound. The refractive index anisotropy of the liquid crystal compound may be in the range of, for example, 0.1 or more, 0.12 or more or 0.15 or more to 0.23 or less or 0.25 or less or 0.3 or less.

The GH layer may further comprise a dichroic dye. The dye may be included as a guest material. The dichroic dye can serve, for example, to control the transmittance of the device in accordance with the orientation of the host material. The term " dye " in the present application may mean a material capable of intensively absorbing and / or deforming light within a visible light region, for example, within a wavelength range of 400 nm to 700 nm, The term " dichroic dye " may mean a material capable of anisotropic absorption of light in at least a part or the entire range of the visible light region.

As the dichroic dye, for example, known dyes known to have properties that can be aligned according to the alignment state of the liquid crystal compound by a so-called host guest effect can be selected and used. Examples of such dichroic dyes include so-called azo dyes, anthraquinone dyes, methine dyes, azomethine dyes, merocyanine dyes, naphthoquinone dyes, tetrazine dyes, phenylene dyes, quaterlylene dyes, benzothiadiazole dyes , Diketopyrrolopyrrole dyes, squalene dyes or pyromethene dyes. However, the dyes applicable in the present application are not limited to the above. As the dichroic dye, for example, a black dye can be used. Such dyes are known, for example, as azo dyes or anthraquinone dyes, but are not limited thereto.

The dichroic dye preferably has a dichroic ratio, that is, a value obtained by dividing the absorption of the polarized light parallel to the long axis direction of the dichroic dye by the absorption of the polarized light parallel to the direction perpendicular to the long axis direction, Or more can be used. The dye may satisfy the dichroic ratio at least at some wavelength or at any wavelength within the wavelength range of the visible light region, for example, within the wavelength range of about 380 nm to 700 nm or about 400 nm to 700 nm. The upper limit of the dichroic ratio may be, for example, 20 or less, 18 or less, 16 or less, or 14 or less.

The ratio of the dichroic dye in the GH layer can be appropriately selected in accordance with the objective properties, for example, the transmittance variable characteristics. For example, the dichroic dye may be present in an amount of at least 0.01, at least 0.1, at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, % Or more, 0.9 wt% or more, or 1.0 wt% or more in the GH layer. The upper limit of the proportion of the dichroic dye in the GH layer is, for example, 2 wt% or less, 1.9 wt% or less, 1.8 wt% or less, 1.7 wt% or less, 1.6 wt% or less, 1.5 wt% or less, 1.4 wt% , 1.3 wt% or less, 1.2 wt% or less, or 1.1 wt% or less.

The total weight of the liquid crystal compound and the dichroic dye in the GH layer may be, for example, about 60 wt% or more, 65 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 At least 90 wt%, or at least 95 wt%, and in other instances less than about 100 wt%, 98 wt% or less, or 96 wt% or less.

The GH layer may further comprise optional additives used in the formation of the known GH layers, if necessary, in addition to the abovementioned components, i.e. liquid crystal compounds and dichroic dyes.

The GH layer may have an anisotropic degree (R) of, for example, about 0.5 or more. The anisotropy (R) can be measured by the method described in Polarized Light in Optics and Spectroscopy, D. S. Kliger et al., Academic Press, 1990.

The anisotropy (R) may, in another example, be at least about 0.55, at least 0.6, or at least 0.65. The anisotropy (R) may be, for example, about 0.9 or less, about 0.85 or less, about 0.8 or less, about 0.75 or less, or about 0.7 or less.

The anisotropy (R) can be achieved by controlling, for example, the kind and / or ratio of the liquid crystal compound (host), the kind and / or the ratio of the anisotropic dye, the cell gap and the like.

The active liquid crystal element includes at least the GH layer, and may further include other necessary configurations.

In one example, the active liquid crystal device may further include an electrode layer formed on one surface or both surfaces of the liquid crystal layer.

In one example, the active liquid crystal device may include first and second substrates disposed opposite to each other, wherein the GH layer may be positioned between the first and second substrates.

As the substrate, known materials can be used without any particular limitation. For example, the substrate may be a glass film, a crystalline or amorphous silicon film, an inorganic film such as quartz or ITO (Indium Tin Oxide) film, or a plastic film.

As the plastic substrate, a TAC (triacetyl cellulose) substrate; A COP (cyclo olefin copolymer) substrate such as a norbornene derivative substrate; (PMMA) substrate, a polycarbonate substrate, a polyethylene (PE) substrate, a polypropylene (PV) substrate, a polyvinyl alcohol (PVA) substrate, a diacetyl cellulose (DAC) substrate, a poly ether sulfone substrate, a polyetheretherketone (PEEK) substrate, a polyetheretherketone (PPS) substrate, a polyetherimide (PEN) substrate, a polyethylenemaphthatate (PEN) substrate, a polyethyleneterephtalate (PET) substrate, a polyimide (PS) A substrate or a substrate including an amorphous fluororesin can be used but is not limited thereto. The thickness of such a substrate is not particularly limited and may be selected within an appropriate range.

An electrode layer may be present on the substrate. For example, an electrode layer may be present on at least one surface or both surfaces of the surface of the substrate facing the GH layer. This electrode layer may be an element for applying an external signal capable of switching the optical axis of the GH layer. The term " inner surface " of the substrate in this application means a surface near both the GH layer and the both surfaces of the substrate.

The electrode layer may be formed using a known material. For example, the electrode layer may include a conductive polymer, a conductive metal, a conductive nanowire, or a metal oxide such as ITO (Indium Tin Oxide). The electrode layer may be formed to have transparency. In this field, various materials and forming methods capable of forming a transparent electrode layer are known, and all of these methods can be applied. If necessary, the electrode layer formed on the surface of the substrate may be appropriately patterned.

A liquid crystal alignment layer may be present on the substrate. The liquid crystal alignment layer may also be formed on an inner surface of the substrate, that is, a surface facing the GH layer. When the above-mentioned electrode layer exists on the substrate, the liquid crystal alignment layer may be formed on the surface of the electrode layer, or may be formed between the electrode layer and the substrate. For example, a liquid crystal alignment layer may be present on at least one surface or both surfaces of the inner surface of the substrate included in the transmittance variable device.

As the alignment layer, various rubbing alignment layers or photo alignment layers known in the art can be used without any particular limitation. The alignment layer may be a horizontal alignment layer or a vertical alignment layer, and in one example, it may be a vertical alignment layer.

The light amount adjusting device may further include a photochromic layer which includes at least the active liquid crystal element and is superimposed on the active liquid crystal element. The fact that the active liquid crystal element and the photochromic layer are overlapped with each other means that both layers overlap each other so that the light transmitted through the active liquid crystal element can be irradiated to the photochromic layer and conversely the light can pass through the photochromic layer, It can mean a condition that can be investigated. 1 is a diagram schematically showing a lateral state of the active liquid crystal device 100 and the photochromic layer 200 superimposed on each other.

The term "photochromic layer" refers to a layer having a so-called photochromic effect. For example, when light such as ultraviolet light is irradiated, its color changes and its transmittance changes. When the irradiation of light ends, Quot; refers to a layer having a reversible action.

The photochromic layer may be formed in various manners as long as it functions as described above. For example, the photochromic layer may be a general photochromic layer or a pressure-sensitive adhesive layer. In the case of the pressure-sensitive adhesive layer, the photochromic layer may include a suitable photochromic material as described later.

In this field, various organic and / or inorganic compounds are known as photochromic materials which can be used in the photochromic layer to exhibit the above-mentioned functions, and a method of realizing the photochromic layer through such compounds is also known.

For example, the inorganic compound capable of forming a photochromic layer includes at least one of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Ru, In, Sn, , Re, Os, Ir, and Bi, and the metal oxide may have a characteristic of absorbing a specific wavelength by local surface plasmon resonance. For example, the wavelength region absorbed by the photochromic layer can be controlled by controlling the kind of the metal, the size of the particles, the distance between particles, and anisotropy.

As the organic compound that can be used for the photochromic layer, any one or more of a diarylethene compound, a spiropyran compound, a spiropyrimidine compound, a viologen compound, an azobenzene compound, and a stilbene compound may be exemplified , A method of adding or removing the terminal functional group of the organic compound, or the like can be used to control the wavelength region in which light is absorbed.

Therefore, in the present application, a known photochromic layer as described above can be suitably selected and used.

In addition, the light amount adjusting device of the present application may further include known elements such as an antireflection layer and a hard coating layer in addition to the above configuration.

The light amount adjusting device may include a light source capable of emitting light to the photochromic layer, and the light source may be located closer to the photochromic layer than the active liquid crystal device.

In addition, the light amount control device is an element that can control transmittance in combination with the active liquid crystal device,

The present application also relates to a transmittance variable device. The term transmissive variable device may refer to a device designed to switch between a transmissive state and a blocked state as described above.

The transmittance variable device may be constituted by the above-described light quantity adjusting device alone, or may include other elements. The type of the other element is not particularly limited and may be, for example, a passive polarization layer or an active GH layer (hereinafter, referred to as a second active GH layer for the sake of distinction from the active GH layer of the light amount control apparatus) Can be illustrated. As the passive polarization layer, for example, a well-known linear polarizer such as a PVA (polyvinyl alcohol) polarizer and the like can be used. The passive polarization layer or the active GH layer may be disposed to overlap with the active liquid crystal element. For example, in the transmissive state, the optical axis of the active GH layer of the active element device of the present application can be kept parallel to the absorption axis of the passive polarization layer, or the active GH layer can be vertically aligned, The optical axis of the active GH layer can be vertically aligned with the absorption axis of the passive polarization layer to maintain the transmission and blocking state.

When the active liquid crystal device and the second active GH layer are included, the optical axis of the active GH layer of the active liquid crystal device and the second active GH layer are maintained in a mutually perpendicular orientation state in a transmission state, And the other one may be horizontally aligned so that the optical axes of the two GH layers are parallel to each other, and the optical axes of the two GH layers may be aligned perpendicular to each other in the blocking state.

As the second active GH layer, a GH layer of the same kind as that contained in the active liquid crystal device described above may be used, or another known active GH layer may be used. This second active GH layer can also switch between a vertically oriented state and a horizontally oriented state.

The light amount adjusting device of the present application may further include an adhesive, for example, an optically transparent adhesive called so-called OCA (optically clear adhesive). For example, the active liquid crystal element and the photochromic layer described above may exist in a state of being adhered to each other by the adhesive or the like. As the pressure sensitive adhesive, a pressure sensitive adhesive layer used for attaching the optical film may be appropriately selected and used. The thickness of the pressure-sensitive adhesive may be appropriately selected in consideration of the object of the present application.

The transmissive variable device of the present application may further comprise a hard coating film. The hard coating film may include a base film and a hard coating layer on the base film. The hard coating film may be appropriately selected from known hard coating films in consideration of the object of the present application. The thickness of the hard coating film may be appropriately selected in consideration of the object of the present application.

The hard coating film may be formed on the outside of the light amount adjusting device through a pressure sensitive adhesive.

The present application may further include an antireflection film as the variable transmissivity device. The antireflection film may include a base film and an antireflection layer on the base film. The antireflection film may be appropriately selected from known antireflection films in view of the object of the present application. The thickness of the antireflection film can be suitably selected in consideration of the object of the present application.

The antireflection film may be formed on the outside of the light amount adjusting device through a pressure-sensitive adhesive. As the pressure-sensitive adhesive, a pressure-sensitive adhesive to be used for adhering the optical film may be appropriately selected and used.

The light amount control device and / or the transmittance variable device as described above can be applied to various applications. Applications for which the transmittance variable device can be applied include openings in an enclosed space including a building such as a window or a sunroof, a container or a vehicle, an eyewear, or the like. The range of the eyewear may include all the eyewear formed so that the observer can observe the outside through the lens, such as general glasses, sunglasses, sports goggles, helmets or augmented reality experience devices.

The present application relates to a light amount adjusting apparatus. In one example, the present application can provide a light amount adjusting device capable of freely adjusting a desired transmittance level, such as a medium transmittance or the like, with a large transmittance difference in a blocking state and a transmissive state, .

Fig. 1 is a light quantity control device according to an example of the present application.
2 is a schematic cross-sectional view of an active liquid crystal device applied in an embodiment of the present application.
3 is a schematic cross-sectional view of a light amount adjusting apparatus applied in the embodiment of the present application.

Hereinafter, the light amount adjusting apparatus of the present application will be described in detail with reference to the embodiments, but the scope of the light amount adjusting apparatus of the present application is not limited by the following embodiments.

Example 1

The active liquid crystal device was manufactured by forming a GH layer between two ITO films on which an ITO (Indium Tin Oxide) electrode layer and a liquid crystal alignment layer were sequentially formed on the surface. The GH layer was formed so as to be able to switch between the STN (Super Twisted Nematic) orientation and the vertical orientation, and the thickness, i.e., the cell gap, was about 6 μm. As the alignment layer, a polyimide-based vertical alignment layer was coated on the ITO electrode layer by bar coating, held at 130 DEG C for about 30 minutes, rubbed with a rubbing cloth to form a thickness of about 200 nm. The GH layer is a nematic liquid crystal (MDA-06-821, Merck) having a dielectric anisotropy of about -4.9 and a refractive index anisotropy of about 0.132 and a dichroic dye having a dichroic ratio of about 6.5 to 8 (X < 12 >, BASF). As shown in FIG. 2, the GH layer 2000 is formed between the two ITO films 1000, and a TAC (triacetylcellulose) film (3000), which is antireflection-treated on one surface of one ITO film 1000 ) Was attached with an adhesive (OCA) to constitute an active liquid crystal device. The transmittance and haze of the active liquid crystal device alone were 27.0% and 1.2% in an initial state, that is, in a state where no voltage was applied, and the transmittance and haze were 70.5% and 0.9 %, And the response speed was less than about 100 ms.

On the other hand, as the photochromic layer, a photochromic layer in which a photochromic material was introduced into a known acrylic pressure-sensitive adhesive layer was used as a pressure sensitive adhesive layer. The transmittance and haze of the photochromic layer were 90.2% and 0.4% and, a 43.3% and 0.4% respectively, the transmittance and the haze when the detection level of UVA 32.7mJ / cm ² irradiation, 89.0 mJ / cm ² when the level of UVA irradiation was respectively the permeability and haze of 20.1% and 0.5%, and , And the transmittance and haze when irradiated with UVA of about 150.2 mJ / cm ² were 15.4% and 0.5%, respectively. The above-mentioned photochromic layer has a wide transmittance variable range, but the response speed is slow, so that the speed required for discoloration in the outdoor environment is about 2 to 3 minutes, and it is about 3 to 6 Minutes. As shown in FIG. 3, the active liquid crystal device is attached to a structure including an external substrate 4000, a pressure-sensitive adhesive layer (photochromic layer) 5000 with a photochromic material introduced therein, and a TAC (triacetylcellulose) film 6000 A light amount control device was constructed. A light source capable of irradiating UVA to the light amount adjusting device was disposed closer to the photochromic layer as compared with the active liquid crystal device and the transmittance according to the energy applied to the photochromic layer and the voltage applied to the active liquid crystal device was evaluated The results are shown in Table 1 below.

UVA irradiation energy (unit: mJ / cm ² ) Applied voltage (unit: V) Transmittance (unit:%) 0 0 26.2 15 67.8 32.7
0 9.3 15 39.4 89.0
0 6.4 15 20.9 150.2
0 5.0 15 19.7

As described above, in the light amount adjusting apparatus of the present application, it is possible to realize a transmittance of at most 67.8% and a transmittance of at least 5.0% by controlling the energy of the light applied to the photochromic layer and the applied voltage, , And the quick response speed of the active liquid crystal element can also quickly bring the transmittance variable speed.

Claims (10)

An active liquid crystal device having an active liquid crystal layer including a liquid crystal compound; and a photochromic layer superimposed on the active liquid crystal device. The liquid crystal display device according to claim 1, wherein the active liquid crystal layer is formed so as to switch between two or more states selected from the group consisting of a vertically aligned state, a horizontally aligned state, a twisted state, a splay aligned state and a cholesteric aligned state Light quantity control device. The apparatus of claim 1, wherein the liquid crystal compound is a nematic liquid crystal. The apparatus of claim 1, wherein the active liquid crystal layer further comprises a dichroic dye guest. The dyed dye according to claim 4, wherein the dichroic dye is selected from the group consisting of azo dyes, anthraquinone dyes, methine dyes, azomethine dyes, merocyanine dyes, naphthoquinone dyes, tetrazine dyes, phenylene dyes, A dyestuff dye, a diketopyrrolopyrrole dye, a squalene dye, or a pyromethene dye. The light amount control device according to claim 1, wherein the active liquid crystal device further comprises an electrode layer formed on one surface or both surfaces of the liquid crystal layer. The light amount control device according to claim 1, wherein the photochromic layer is a pressure-sensitive adhesive layer containing a photochromic material. The method of claim 1, wherein the photochromic layer comprises at least one of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Ru, In, Sn, Sb, Ta, And an oxide of at least one metal selected from the group consisting of Bi and Bi. The photochromic device according to claim 1, wherein the photochromic layer comprises at least one compound selected from the group consisting of a diarylethene compound, a spiropyran compound, a spiropyrimidine compound, a viologen compound, an azobenzene compound, and a stilbene compound . The light amount control device according to claim 1, further comprising a light source arranged to emit light to the photochromic layer.

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