JP5900233B2 - Light control element, light control device, and driving method thereof - Google Patents

Description

  The present invention relates to a light control element, a light control device, and driving methods thereof.

  As a background art of this technical field, there is Patent Document 1. Patent Document 1 has a light control layer formed by dispersing a light control suspension containing light control particles dispersed in a flowable state in a dispersion medium in a resin matrix formed from a polymer medium, The light control layer is described as a light control film in which the light control layer is sandwiched between transparent conductive substrates and exhibits a light control function depending on whether or not an electric field is applied at a low frequency (see summary).

JP 2008-158043 A

  In Patent Document 1, it is possible to develop a dimming function depending on whether or not a low-frequency electric field is applied. However, in any case, dimming driving is only performed in a transparent state or an intermediate state by applying an AC voltage, and at high speed. It is difficult to adjust light from a transmission state or an intermediate state to a light shielding state. An object of the present invention is to provide a light control element, a light control device, and a driving method thereof capable of performing light control from a transmission state or an intermediate state to a light shielding state at high speed.

The features of the present invention for solving the above problems are as follows, for example.
A first substrate and a second substrate, on the first substrate, a first electrode formed between the first substrate and the second substrate, and on the second substrate, between the first substrate and the second substrate A second electrode formed on the substrate, a suspension formed between the first electrode and the second electrode, and a first concavo-convex shape formed between the first substrate and the suspension. The turbid liquid includes dimming particles and a dispersion medium, and the dimming particles are controlled by applying a voltage to the first electrode and the second electrode, and the first uneven shape is a dimming element or dimming having a tapered shape. A light control device provided with an element.

  A first substrate and a second substrate, on the first substrate, a first electrode formed between the first substrate and the second substrate, and on the second substrate, between the first substrate and the second substrate A second electrode formed on the substrate, a suspension formed between the first electrode and the second electrode, and a first concavo-convex shape formed between the first substrate and the suspension. An optical element driving method, wherein a suspension includes light control particles and a dispersion medium, and the light control particles are controlled by applying a voltage to the first electrode and the second electrode. A method of driving a light control element having a tapered shape and applying a DC voltage between a first electrode and a second electrode to place the light control element in a light-shielded state.

  According to the present invention, it is possible to provide a light control element, a light control device, and a driving method thereof capable of performing light control from a transmission state or an intermediate state to a light shielding state at high speed. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a schematic sectional drawing which shows the structure and light-shielding state of the light modulation apparatus of one Embodiment. It is the schematic which shows the structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is a schematic sectional drawing which shows the structure and permeation | transmission state of the light modulation apparatus of one Embodiment. It is a schematic sectional drawing which shows the structure and permeation | transmission state of the light modulation apparatus of one Embodiment. It is a schematic sectional drawing which shows the structure and light-shielding state of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is a schematic sectional drawing which shows the structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is a schematic sectional drawing which shows the structure and light-shielding state of the light modulation apparatus of one Embodiment. It is a schematic sectional drawing which shows the structure and light-shielding state of the light modulation apparatus of one Embodiment. It is a schematic sectional drawing which shows the structure of the light modulation apparatus of one Embodiment, a permeation | transmission state, and a light-shielding state. It is a schematic sectional drawing which shows the structure of the light modulation apparatus of one Embodiment, a permeation | transmission state, and a light-shielding state. It is the schematic which shows a part of structure of the light modulation apparatus of one Embodiment. It is a schematic sectional drawing which shows the structure of the light modulation apparatus of one Embodiment. It is a schematic sectional drawing which shows the structure of the light modulation apparatus of one Embodiment. It is a schematic sectional drawing which shows the structure of the light modulation apparatus of one Embodiment, and the intermediate state of a permeation | transmission state and a light-shielding state.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following examples show specific examples of the contents of the present invention, and the present invention is not limited to these examples, but by those skilled in the art within the scope of the technical idea disclosed in this specification. Various changes and modifications are possible. Further, in all the drawings for explaining the embodiments, the same reference numerals are given to those having the same function, and repeated explanation thereof is omitted.

  1, 2, and 3 are schematic views of a light control device according to an embodiment, and the light control device 1000 includes a light control element 100 and a drive circuit 200. The light control device 100 includes a first electrode 11, a first substrate 10, a second electrode 21, and a second substrate 20. In FIG. 1, the 1st electrode 11, the 1st board | substrate 10, the 2nd electrode 21, and the 2nd board | substrate 20 are flat form (solid form). The first electrode 11 is formed on the first substrate 10, and the second electrode 21 is formed on the second substrate 20. The first electrode 11 and the second electrode 21 are arranged so as to sandwich the suspension 32 with a predetermined gap. A first concavo-convex shape 12 having a tapered shape is disposed on the first electrode 11, that is, on the side where the suspension 32 is formed with respect to the first electrode 11. The suspension filling space formed by the predetermined gap is filled with the suspension 32.

  The suspension 32 includes light control particles 31 and a dispersion medium 30, and the light control particles 31 are dispersed in the dispersion medium 30. In the present embodiment, as shown in FIG. 2, the first substrate 10 and the second substrate 20 are shifted and overlapped when viewed from the in-plane normal direction of the first substrate 10, and the first electrode connecting portion 11a and the second substrate 20 are overlapped. The first electrode 11 and the second electrode 21 are connected to the drive circuit 200 by the electrode connection portion 21a.

The light control device of the present embodiment can be manufactured, for example, by the following method.
First, a set of glass substrates on which a transparent electrode made of indium tin oxide (ITO) is formed is prepared, and the first substrate 10, the first electrode 11, the first electrode connection portion 11a, the second substrate 20, and the second electrode 21 are formed. The second electrode connection portion 21a is used. The patterning of the first electrode 11, the first electrode connection portion 11a, the second electrode 21, and the second electrode connection portion 21a is performed by a photolithography technique.

  Further, as shown in FIG. 3, a UV curable acrylic resin is applied on the first electrode 11, molded with a mold having a concavo-convex shape opposite to the desired first concavo-convex shape 12, and cured by UV light. By doing so, the first concavo-convex shape 12 is formed on the first electrode 11.

  Next, the first electrode 11 and the second electrode 21 are opposed to each other, and a sealing agent containing spacer beads or the like is applied to opposite sides of both substrate ends to bond the two substrates (not shown). Thereby, a suspension filling space of the suspension 32 having a distance of 25 μm is formed between both the substrates.

  The suspension filling space is filled with the suspension 32 by capillarity from the ends of the first substrate 10 and the second substrate 20 that are not bonded with the sealing agent. The suspension 32 is composed of, for example, a dispersion medium 30 made of an acrylate oligomer and light control particles 31 made of polyiodide. The light control particles 31 are anisotropic in shape, exhibit optical anisotropy having different absorbance due to the orientation direction, have a shape with an aspect ratio not 1, and are negatively charged. . The concentration of the light control particles 31 in the suspension 32 is, for example, 3.7 wt%.

  After the suspension 32 is filled in the suspension filling space, the end portions of the first substrate 10 and the second substrate 20 that are not bonded are bonded and sealed with a sealing agent, whereby the light control device 100 is completed. . Furthermore, the light control device of the present embodiment is configured by wiring-connecting the first electrode 11 and the second electrode 21 of the light control element 100 to the drive circuit 200 via the first electrode connection portion 11a and the second electrode connection portion 21a. Produced.

  The light control device of the present embodiment manufactured by the above configuration and manufacturing method is described below by applying a plurality of drive waveforms to the first electrode 11 and the second electrode 21 from the drive circuit 200 by a plurality of drive waveforms. In addition, the light can be adjusted to a transmission state, a light shielding state, or an intermediate state thereof.

  In an initial state in which no voltage is applied, the light control particles 31 are in a random state as shown in FIG. 1 and light incident on the light control element 100 (incident from the first substrate 10 toward the second substrate 20 or the second substrate 20). Light entering the first substrate 10) is absorbed by the light control particles 31.

By applying a predetermined alternating voltage between the first electrode 11 and the second electrode 21 by the drive circuit 200, the light control particles 31 are substantially perpendicular to the in-plane directions of the first substrate 10 and the second substrate 20. Line up (Fig. 4). In this state, the light incident on the light control element 100 is not easily absorbed by the light control particles 31 and is in a transmission state. Moreover, the light control particle 31 takes an intermediate state between the random state and the orientation state perpendicular to the in-plane directions of the first substrate 10 and the second substrate 20 by lowering the AC applied voltage below the predetermined voltage. Therefore, the light control element 100 can obtain an arbitrary transmission state (not shown). The AC voltage here includes a sine wave, a square wave, a triangular wave, or a waveform of any combination of these, and the frequency and waveform may fluctuate somewhat. The frequency f is preferably in the range of 30 Hz <f <1000 Hz. The applied voltage V depends on the distance between the first electrode 11 and the second electrode 21, but is approximately 5V <V <300V, and the electric field strength E is 0.1 × 10 ⁶ V / m <E <1 × 10 ⁷ V. A range of / m is preferred. For example, if a sine wave can be driven at a frequency of about 50 Hz and a voltage of 100 V, a voltage supplied from a general domestic outlet can be used.

The drive circuit 200 applies a DC voltage between the first electrode 11 and the second electrode 21 so that the potential on the second electrode 21 side is higher than the first electrode 11, whereby the dimming particles 31 that are negatively charged are The second electrode 21 moves while being oriented so as to be perpendicular to the in-plane direction of the second substrate 20, and the orientation is maintained on the second electrode 21. In this state, the light incident on the light control element 100 is not easily absorbed by the light control particles 31 and is in a transmission state (FIG. 5). The DC voltage here depends on the distance between the first electrode 11 and the second electrode 21, but is approximately 5 V <V <300 V, and the electric field strength E is 0.1 × 10 ⁶ V / m <E <1 × 10 ^7. A range of V / m is preferred. Further, the polarity of the applied voltage may be made two steps while keeping the same polarity. For example, in order to quickly move the light control particles 31, it is possible to drive the light control particles 31 to the second electrode 21 at a high voltage of 100V, and to keep the alignment state of the light control particles 31 at a low voltage of 50V after the movement. In addition, a waveform having a plurality of steps and a slope shape can be applied.

The DC voltage is applied so that the drive circuit 200 has a polarity opposite to that of the above-described DC voltage application, that is, the potential on the first electrode 11 side is higher than the second electrode 21 between the first electrode 11 and the second electrode 21. Is applied, the negatively charged light control particles 31 move to the first electrode 11 side and reach the first uneven shape 12. Since the light control particles 31 that have reached the first uneven shape 12 still receive a downward force due to the potential difference, the inclined state (tapered portion) of the first uneven shape 12 can maintain an alignment state perpendicular to the first substrate 10. The light control particle 31 falls on the slope and becomes a random state on the first concavo-convex shape 12. In this state, the light control particle 31 absorbs the light incident on the light control element 100 (FIG. 6). The DC voltage here depends on the distance between the first electrode 11 and the second electrode 21, but is approximately 5 V <V <300 V, and the electric field strength E is 0.1 × 10 ⁶ V / m <E <1 × 10 ^7. A range of V / m is preferred. Further, the polarity of the applied voltage may be made two steps while keeping the same polarity. For example, in order to quickly move the light control particles 31, the light is moved to the first uneven shape 12 on the first electrode 11 with a high voltage of 100 V, and the alignment of the light control particles 31 is disturbed by the uneven shape of the first uneven shape 12. After that, it is possible to drive such that the orientation of the light control particles 31 is disturbed at a low voltage of 50V. Further, the present invention can be applied to a case where the waveform is formed in a plurality of stages or in a slope shape.

  Once the light control particles 31 reach the first concave / convex shape 12, the voltage application is stopped to diffuse from the top of the first concave / convex shape 12 by Brownian motion or the like. Therefore, the light is blocked (FIG. 1). On the other hand, when the application of voltage is stopped from the above-described transmission state or intermediate state, the light control particles 31 diffuse due to Brownian motion or the like, and return to the light shielding state (FIG. 1).

  As described above, in this embodiment, it is possible to provide a light control device capable of taking a transmission state, an intermediate state, and a light shielding state by a plurality of drive waveforms taking an AC voltage and a DC voltage, and a driving method thereof. As a result, dimming operation can be performed with the same dimming element for various driving circuits such as a driving circuit that supplies only a DC voltage, a driving circuit that supplies only an AC voltage, or a driving circuit that can supply both. Become.

  Further, in the light control device of this embodiment, it is possible to move the light control particles 31 onto the first concavo-convex shape 12 by applying a DC voltage so as to be in a light-shielded state. Compared with the case of waiting for the diffusion of the light particles 31 to be in the light shielding state, the light can be adjusted from the transmission state or the intermediate state to the light shielding state at a higher speed.

  In addition to the above-described members, the light control device of the present embodiment can appropriately use the following members.

  The first substrate 10 and the second substrate 20 are substrates that transmit at least some wavelengths of visible light, such as transparent inorganic substrates such as various types of glass and quartz, polyethylene terephthalate (PET), polycarbonate (PC), and cycloolefin. A transparent resin substrate such as a polymer (COP) can be used. Moreover, the board | substrate colored according to the use and the board | substrate with a scattering property can also be utilized. In addition, by using a substrate that reflects visible light or a layer that reflects light on either the first substrate 10 or the second substrate 20, it is possible to form a light control device that can perform light modulation in a reflective state and a light-shielded state. It is.

  The first electrode 11, the first electrode connecting portion 11a, the second electrode 21, and the second electrode connecting portion 21a are electrodes formed on the first substrate 10 and the second substrate 20, and at least a part of visible light. Indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide, zinc oxide, carbon nanotubes, graphene, and the like that can transmit the above wavelengths can be used. Further, a metal such as silver or various conductors may be converted into nanowires and dispersed in a resin to form a transparent electrode. In this embodiment, the transparent electrode is formed in a solid shape on the first substrate 10 or the second substrate 20, but the transparent electrode is not limited to this and may be arranged in a pattern such as a circle or a character type. Even when the wiring itself does not transmit visible light, such as copper, chromium, Ag, aluminum, and various metals, the electrodes are comb-shaped and the width of each of the comb-shaped wirings is reduced to reduce the light shielding rate by the wiring. It is also possible to use it by reducing the number. Also, a plurality of materials such as changing the material between the first electrode 11, the second electrode 21, the first electrode connecting portion 11a, and the second electrode connecting portion 21a may be used.

  Examples of the spacer beads include glass and polymer, and it is desirable that the spacer beads are stable with respect to the adhesive. The distance between the suspension filling space and the two substrates is preferably 4 μm or more and 150 μm or less from the viewpoint of transmittance and driving voltage. Alternatively, spacer beads may be dispersed between the first substrate 10 and the second substrate 20 to maintain the suspension filling space. When the spacer beads are scattered between the first substrate 10 and the second substrate 20, it is preferable that the spacer beads have a refractive index close to that of the dispersion medium 30 because the spacer beads are not scattered due to the difference in refractive index. The difference between the refractive index of the preferred spacer beads and the refractive index of the dispersion medium 30 is Δn <0.2, more preferably Δn <0.1.

  The suspension 32 is obtained by dispersing the light control particles 31 in the dispersion medium 30 and fills the suspension filling space formed between the first substrate 10 and the second substrate 20. In this embodiment, the suspension 32 is filled by a capillary phenomenon, but before the first substrate 10 and the second substrate 20 are bonded to each other, the bar coating method or the dropping injection method (ODF) method under vacuum is used. The first substrate 10 and the second substrate 20 may be bonded to each other and bonded and sealed.

  The light control particles 31 are, for example, polyperiodide, have anisotropy in shape, exhibit optical anisotropy having different absorbance due to the orientation direction, and have a shape in which the aspect ratio is not 1. ing. In the process of synthesizing the light control particles 31, nitrocellulose or the like may be added to increase the uniformity of the particle size. The operation of such a light control particle 31 can be controlled by applying a voltage, that is, the light control particle 31 is oriented in application of an AC voltage in a certain frequency range, and is unidirectional in application of a DC voltage. It is desirable to move (positively or negatively charged). It is desirable to use a dielectric material with low conductivity as the light control particles 31. Examples of the dielectric material having low conductivity include polymer particles and particles coated with a polymer.

  The shape of the light control particle 31 may be a rod shape or a plate shape. In particular, by making the light control particles 31 into a rod shape, it is possible to suppress the resistance of the particle rotational motion to the electric field and the increase in haze during transmission. At this time, the aspect ratio of the minor axis to the major axis of the light control particles 31 is preferably about 5 or more and 30 or less, for example. By setting the aspect ratio to 5 or more, optical anisotropy due to the shape of the light control particles 31 can be expressed.

  When the light control particles 31 are rod-shaped or plate-shaped, the size of the long axis of the light control particles 31 is preferably 1 μm or less, more preferably 0.1 μm to 1 μm, and more preferably 0.1 μm to 0 μm. More preferably, it is 0.5 μm or less. If the size of the long axis of the light control particle 31 exceeds 1 μm, light scattering occurs, and the orientation movement in the dispersion medium 30 decreases when an electric field is applied. This is because problems may occur. In addition, the magnitude | size of the light control particle 31 is measured by electron microscope observation etc.

  In addition to the above polyiodide, the light control particles 31 are made of carbon-based materials such as carbon black, metal materials such as copper, nickel, iron, cobalt, chromium, titanium, and aluminum, silicon nitride, titanium nitride, and aluminum oxide. It is also possible to use particles made mainly of these inorganic compounds. These materials can be used as light-controlling particles obtained by surface-coating or surface-treating with a polymer or the like and imparting the aforementioned orientation and charging functions. As the light control particles 31, only one type of the above material may be included, or two or more types of the above materials may be included.

Examples of the dispersion medium 30 include a liquid copolymer composed of an acrylate oligomer, polysiloxane (silicone oil), and the like. Also, a dispersion medium in which a plurality of these materials are blended to improve viscosity adjustment and reliability can be used. The light control particles 31 have a floating and operable viscosity, high resistance, no affinity with the first substrate 10, the second substrate 20, the first electrode 11, and the second electrode 21, and the refractive index thereof. Nearly, it is preferable to use a liquid copolymer having a dielectric constant different from that of the light control particles 31. Specifically, it is desirable that the resistivity of the dispersion medium 30 is 10 ¹² Ωm or more and 10 ¹⁵ Ωm or less at a temperature of 298K. When there is a dielectric constant difference between the dispersion medium 30 and the light control particles 31, the light control particles 31 can act as a driving force for alignment under an alternating electric field in the alignment operation. The relative dielectric constant of the dispersion medium 30 is preferably 3.0 or more and 5.0 or less.

  The first concavo-convex shape 12 is a material that transmits at least a part of the wavelength of visible light, and includes a transparent resin material such as polyethylene terephthalate (PET), polycarbonate (PC), acrylic, epoxy, and cycloolefin polymer (COP). Various types of glass, quartz, etc. can be used by molding on the first substrate 10 by any molding or processing method or pasting them together. In particular, a UV curable resin or a thermosetting resin is applied onto the first substrate 10, cured while pressing a mold such as a mold, and the first concavo-convex shape 12 is collectively formed on the first substrate 10. This is preferable from the viewpoint of simplification.

  Alternatively, an uneven shape may be provided in advance on the first electrode 11 side of the first substrate 10 (FIG. 7A), and the first electrode 11 may be formed along the uneven shape to obtain the first uneven shape 12. By forming the first concavo-convex shape 12 as shown in FIG. 7A, the types of members for forming the concavo-convex structure can be reduced. Moreover, the 1st electrode 11 which has uneven | corrugated shape may be formed on the flat 1st board | substrate 10, and you may serve as the 1st uneven | corrugated shape 12 (FIG.7 (b)). As shown in FIG. 7B, the first electrode 11 also serves as the first concavo-convex shape 12, whereby the types of members for forming the concavo-convex structure can be reduced. The first concavo-convex shape 12 may be a substantially isotropic bowl shape as shown in FIG. 8A, a bowl shape long in one direction as shown in FIG. 8B, or a groove shape as shown in FIG. 8C. Moreover, these may be arranged periodically and the unevenness | corrugation from which a size and a shape differ may be arrange | positioned at random. Since the bowl shape as shown in FIG. 8B is substantially isotropic, the particles fall down in all directions, and the light shielding property is good.

  Further, the first concavo-convex shape 12 of this embodiment requires a tapered portion 120 as shown in FIGS. 9A, 9B, and 9C for eliminating the orientation of the light control particles 31. FIG. . As the taper portion 120, the cross-sectional shape when cut perpendicularly to the substrate at the shortest distance of each concavo-convex opening is various curves such as an arc, an ellipse, and a parabola as shown in FIG. ), A line having a plurality of vertices as shown in FIG. 9C, or a combination of these arbitrarily. The taper portion 120 is that an angle between a tangent line in the cross section of the first concavo-convex shape 12 and the first substrate 10 has an angle in a range of at least 0 ° <θ <90 °.

  In addition, when the size of the first uneven shape 12 is larger than the length of the light control particle 31 in the major axis direction, the light control particle 31 that has moved to the first uneven shape 12 by applying a DC voltage is converted into the first uneven shape. In the vicinity of the convex portions of the first concave-convex shape 12, the light-controlling particles 31 are almost absent, that is, the light-shielding property is lowered. Therefore, the depth d of the cross-sectional shape of the first concavo-convex shape 12 when the length of the light control particle 31 in the major axis direction is l is 0.1 l <d <20 l, more preferably 0.5 l <d <3 l. When the short axis direction of the opening having the cross-sectional shape of the first concavo-convex shape 12 is w, it is desirable that w <20 l, more preferably w <6 l. Assuming that the maximum value of the angle formed between the tangent to the first concavo-convex shape 12 and the surface of the first substrate 10 is θmax, 20 ° <θmax ≦ 90 °, more preferably 45 ° <θmax ≦ 90 °, The light control particles 31 easily fall down at the tapered portion 120, and a good light shielding state is obtained.

  Further, the material of the first concavo-convex shape 12 used here is suitable as the dispersion medium 30 is closer to the refractive index, and the scattering by the interface is less likely to occur. The refractive index difference Δn between the refractive index of the first uneven shape 12 and the refractive index of the dispersion medium 30 is Δn <0.2, more preferably Δn <0.1. The material based on the resin material is easier to match the refractive index with the dispersion medium 30. Further, by forming the first concavo-convex shape 12 with a resin material, the first electrode 11 is not directly brought into contact with the suspension 32, but is deteriorated due to an electrochemical reaction at the electrode-suspension interface during voltage application. There is also an advantage of suppressing.

  10 and 11 are schematic views of the light control device according to the embodiment, except that the partition wall 33 is disposed between the first substrate 10 and the second substrate 20, and the suspension 32 is subdivided by the partition wall 33. Is the same as in the previous embodiment. In FIG. 10, the partition 33 is configured to contact the second electrode 21 in order to divide the suspension 32 into small portions.

  In the present embodiment, in addition to the above-described effects, the suspension 32 is subdivided by the partition wall 33. Therefore, the bias of the light control particles 31 in the light control element 100 is suppressed, and the in-plane transmittance is further increased. A light control device having a uniform distribution can be provided. Further, since the suspension 32 is subdivided by the partition wall 33, the outflow amount of the suspension 32 when the dimming element 100 is arbitrarily cut can be limited to a very small amount. Therefore, especially when using resin substrates, such as PET, for the 1st board | substrate 10 and the 2nd board | substrate 20, it can cut according to the size which the light control element 100 wants to utilize. Moreover, the light control element 100 can be made to have a more durable structure by providing the partition wall 33.

  When viewed from the in-plane normal direction of the first substrate 10, the shape of the partition wall 33 is, for example, a quadrangular shape shown in FIG. 11A, a linear shape (groove shape) as shown in FIG. Hexagonal shape as shown in c). By making the shape of the partition wall 33 into a linear shape as shown in FIG. 11B, the area in which the light control particles 31 can move is large, the difference between light shielding and transmission can be made large, and the aperture ratio can be widened. By making the shape of the partition wall 33 a hexagonal shape as shown in FIG. 11C, the light control element 100 can be made to have a more durable structure. The shape of the partition 33 is not limited to these, and the same effect can be acquired even if it is a random shape. The distance from the surface of the adjacent partition wall 33 to the surface is preferably 20 μm or more and 500 μm or less, and the width of the partition wall 33 is 50 μm or less, more preferably 20 μm or less. In particular, as shown in FIG. 11, the portion other than the partition wall 33 when viewed from the in-plane normal direction of the first substrate 10 is a region in which the dimming particles 31 are dimmed. It is preferable that the area ratio of the partition wall 33 to the area of the first substrate 10 or the second substrate 20 when viewed from the in-plane normal direction is smaller. For example, the area ratio of the partition wall 33 is desirably 50% or less.

  Examples of the partition wall 33 include a transparent insulating dielectric material made of, for example, glass or polymer, and it is preferable that the partition wall 33 is stable with respect to other constituent materials.

  Moreover, the refractive index of the dispersion medium 30 and the partition 33 is brought close to each other, and the reflection at the interface between the two is reduced to make the partition 33 less noticeable. The refractive index difference Δn between the preferable dispersion medium 30 and the partition wall 33 is Δn <0.2, more preferably Δn <0.1. In particular, when the partition wall 33 and the first concavo-convex shape 12 are made of the same material, the first concavo-convex shape 12 and the partition wall 33 can be collectively formed on the first substrate 10 on which the first electrode 11 is formed using, for example, a mold. The process can be simplified. At this time, the thickness of the partition wall 33 on the first substrate 10 side may be larger than the thickness of the partition wall 33 on the second substrate 20 side so that the partition wall 33 can be easily removed from the mold. Then, the light control element 100 can be manufactured by filling the suspension 32 into the region subdivided by the partition wall 33 and attaching the suspension 32 to the second substrate 20 on which the second electrode 21 is formed. Alternatively, the suspension 32 may be filled in each region divided by the partition wall 33, sealed with a UV curable resin or a photocurable resin, and then bonded to the second substrate 20. The first uneven shape 12 and the partition wall 33 may be separate members.

  In order to further reduce the transmittance in the light-shielding state, at least the top portion or the whole of the partition wall 33 may be colored black, and / or the convex portion or the whole of the first uneven shape 12 may be colored black. Even when the first concavo-convex shape 12 and the entire partition 33 are colored black, the thickness of the concave portion of the first concavo-convex shape 12 is small, so that light is transmitted, and the thickness of the convex portion of the first concavo-convex shape 12 and the partition wall Since the thickness of 33 is large, it can block light. Since the light control particles 31 do not get on or fall over the convex portions of the first concavo-convex shape 12 or the partition wall 33, the transmittance during light shielding can be further reduced. Moreover, when the partition 33 or the 1st uneven | corrugated shape 12 whole is colored with black, the partition 33 or the 1st uneven | corrugated shape 12 can be collectively produced with the same material.

  Further, other colors may be used for correcting the chromaticity of the transmitted light of the light control element 100. For example, when the light control element 100 (light control particles 31) that transmits a large amount of blue light in a light-shielded state is used, the light-blocking state is obtained by using a partition wall 33 that transmits a complementary yellow wavelength. The blue light can be brought closer to an achromatic color. In this case, the top part or the whole of the partition wall 33 is colored with a complementary color of the color when the light control element 100 is shielded, or / and the convex part or the whole of the first uneven shape 12 is colored with the light when the light control element 100 is shielded. A complementary color may be used. If the achromatic color is not completely achromatic when transmitted through the light control element 100, only the first uneven shape 12 may be colored to the complementary color of the color at the time of shading.

  FIG. 12 is a schematic view of a light control device according to an embodiment, which is the same as the above-described example except that the subdivision structures of Example 2 are stacked. FIG. 12 shows a light shielding state obtained by applying a DC voltage between the first electrode 11 and the second electrode 21, and an arrow in the figure indicates a light ray incident on the light control element 100. In FIG. 12, the first-layer partition 331 is configured to contact the second electrode 21, and the second-layer partition 332 is configured to contact the first-layer uneven shape 121. That is, the uneven shape 121 and the uneven shape 122 which are a plurality of uneven shapes are stacked on the first electrode 11.

  The light incident on the first-layer partition wall 331 as in the light ray (a) in the figure, and the light incident on the convex portion of the first uneven surface 121 as in the light beam (b) The second layer subdivision structure is reached without being absorbed by the light particles 311, but the first layer partition 331 and the second layer partition 332, and the convex portions of the first layer uneven shape 121 as in this embodiment. And the convex part of the uneven | corrugated shape 122 of the 2nd layer can be light-shielded by the light control particle 31 of the 2nd layer because it arrange | positions shifting | deviating when it observes from the in-plane normal line direction of the 1st board | substrate 10. In other words, in this embodiment, in addition to the above-described effects, there is an effect of preventing light leakage particularly through the concavo-convex convex portions or partition walls at the time of light shielding. The convex portions of the first-layer concavo-convex shape 121 and the convex portions of the second-layer concavo-convex shape 122 may all be shifted from each other when observed from the in-plane direction of the first substrate 10, or a part thereof It may be displaced. In order to increase the light shielding effect of the second layer of light control particles 31, the convex portions of the first layer uneven shape 121 and the convex portions of the second layer uneven shape 122 are observed from the in-plane direction of the first substrate 10. In this case, it is desirable that they are all displaced.

  Similarly, as shown in the schematic diagram of the light control device according to one embodiment of FIG. 13, a structure in which a plurality of minute subdivision structures are provided in the partition wall 33 and each micro subdivision structure has a concave shape 123 is also the same. The effect is obtained. Even if the minute subdivision structure is regularly shifted or random, there is an effect of preventing light leakage through the partition wall as described above. Moreover, although not shown in figure, you may have a some uneven | corrugated shape instead of a concave shape in a minute subdivision area | region.

  14 and 15 are schematic views of the light control device according to the embodiment, which are the same as those in the above-described example except that the second electrode 21 is formed in a comb shape on the second substrate 20.

  In this embodiment, when a voltage is applied by the drive circuit 200 so that the potential of the second electrode 21 is higher than the potential of the first electrode 11, as shown in FIG. Are unevenly distributed in the comb-like second electrode 21 and become transparent. Further, even when no voltage is applied, this state is maintained for a while due to the mirror image effect between the light control particles 31 and the second electrode 21 and the intermolecular force between the light control particles 31 and between the light control particles 31 and the second electrode 21. . Moreover, although the light control particle 31 diffuses gently and shifts to a light shielding state, it takes time until it completely enters the light shielding state. That is, in this embodiment, in addition to the above-described effects, there is an effect that it is possible to provide a light control element having a memory property that maintains the transmission state even when no voltage is applied.

  In addition, since the diffusion speed of the light control particles 31 (the transition speed from the DC voltage application state to the light shielding by diffusion when no voltage is applied) depends on the viscosity of the dispersion medium 30, by using the dispersion medium 30 having a high viscosity, This memory time can be lengthened. On the other hand, increasing the viscosity to increase the memory time means that it takes time to shift to a light-shielding state by diffusion. In this embodiment, as shown in FIG. 31 can be migrated toward the first electrode 11, and the light control particles 31 can be shifted to a light-shielding state in which the light control particles 31 are randomly tilted by the tapered portion of the first concavo-convex shape 12. In other words, in addition to the above-described effects, it is possible to provide a light control device that has both long-term memory performance in a transmissive state and high-speed light shielding.

  The wiring width in the minor axis direction of the comb-shaped second electrode 21 and the inter-wiring distance between adjacent comb-shaped second electrodes 21 are the transmittance when the light control particles 31 are unevenly distributed on the second electrode 21. Therefore, it is preferable that the width of the wiring in the minor axis direction is narrow and the distance between the wirings is wide because higher transmittance is obtained. As an example, it is preferable that the wiring width of the comb-like second electrode 21 is 10 μm and the wiring interval is 50 μm.

  In addition, as shown in the schematic diagram of the light control device according to the embodiment of FIG. 16, this example can be used together with the structure having the partition wall 33 as in Example 2. At this time, it is preferable that at least one or more comb-shaped second electrodes 21 are present in each subdivided region. The comb-shaped second electrode 21 may be disposed between each partition wall 33 and the second substrate 20 (not shown). Moreover, the period of the partition 33 in a certain direction may be an integral multiple of the period of each wiring of the comb-shaped second electrode 21.

  Moreover, since the area of the electrode to be utilized can be reduced by making the 2nd electrode 21 into a comb-tooth shape instead of a solid shape, there exists a resource-saving effect. In particular, since rare materials such as indium used for ITO or the like have a large price fluctuation, reduction of the amount of use thereof is desired.

  FIG. 17 is a schematic view of a light control device according to an embodiment, which is the same as the above-described example except that the second uneven shape 22 is provided on the second electrode 21.

  In the present embodiment, the transmission state is obtained by AC driving from the driving circuit 200. On the other hand, the light shielding state can be obtained by causing the light control particles 31 to migrate to either the first uneven shape 12 or the second uneven shape 22 by direct current drive. Therefore, in addition to the effects described above, it is possible to provide a dimming device that can be used without considering the polarity of voltage application when the dimming element 100 is switched from the drive circuit 200 to the transmission state or the light shielding state. Similarly to the first uneven shape 12, the second uneven shape 22 may be formed as shown in FIGS.

  Further, in the light control device according to the present embodiment, the light control particles 31 are moved to the first concavo-convex shape 12 side when the DC voltage is applied to make the drive circuit 200 shield the light, and the second concavo-convex shape 22 is used. Since it is also possible to alternate the case where the light control particles 31 are moved to the side, the positive and negative impurity ions contained in the suspension 32 are prevented from being biased to the first electrode 11 and the second electrode 21, and the electrode It is possible to prevent a voltage drop between them. In addition, there is an effect of reducing the causes of defects such as electrode elution due to electrochemical reaction and electrode migration caused by continuing to apply a voltage in one direction.

  Furthermore, as shown in the schematic diagram of the light control device of one embodiment of FIG. 18, the light control particles 31 are moved to the second uneven shape 22 side by keeping a part of the second uneven shape 22 flat. In the flat portion, the light control particles 31 are oriented perpendicularly to the second electrode 21 and are partially transmissive, and in the recesses of the second concavo-convex shape 22, the light control particles 31 are tilted and partially light shielded. Therefore, the intermediate state between the transmission state and the light shielding state can be taken as a whole. That is, in addition to the effects described above, it is possible to provide a light control device that can drive the light control element to a light shielding state and an intermediate state with a DC voltage. In addition to providing a flat portion on the second uneven shape 22 as in the present embodiment, it is also possible to adjust the taper portion to an intermediate state according to the angle and shape of the tapered portion. In order to obtain the above effect, a part of the first uneven shape 12 may be flattened, and a part of both the first uneven shape 12 and the second uneven shape 22 may be flattened. .

DESCRIPTION OF SYMBOLS 10 1st board | substrate 11 1st electrode 11a 1st electrode connection part 12 1st uneven | corrugated shape 20 2nd board | substrate 21 2nd electrode 21a 2nd electrode connection part 22 2nd uneven | corrugated shape 30 Dispersion medium 31 Light control particle 32 Suspension 33 Partition 100 Light control element 120 Taper part 200 Drive circuit 1000 Light control device

Claims (19)

A first substrate and a second substrate;
A first electrode on the first substrate and formed between the first substrate and the second substrate;
A second electrode on the second substrate and formed between the first substrate and the second substrate;
A suspension formed between the first electrode and the second electrode;
A first concavo-convex shape formed between the first substrate and the suspension,
The suspension includes light control particles and a dispersion medium,
The dimming particles are controlled by applying a voltage to the first electrode and the second electrode,
The first uneven shape have a tapered shape,
The light control particles are rod-shaped,
The aspect ratio of the light control particles is 5 or more and 30 or less,
The light modulating element that reaches the first uneven shape falls on the slope of the first uneven shape, and becomes a random state on the first uneven shape . In claim 1,
A partition is formed between the first substrate and the second substrate,
A light control element in which the suspension is subdivided by the partition walls. In any one of Claims 1 thru | or 2.
A second uneven shape is formed between the suspension and the second substrate,
The dimming element in which the second concavo-convex shape has a tapered shape. In any one of Claims 1 thru | or 2 .
The first uneven shape is a light control element formed of a resin material. In claim 3,
The light control element in which said 1st uneven | corrugated shape or said 2nd uneven | corrugated shape is formed with the resin material. In claim 3 or 5 ,
A dimming element having a portion where a position of the convex portion of the second concavo-convex shape is shifted from a position of the convex portion of the first concavo-convex shape when observed from an in-plane normal direction of the first substrate. In claim 1 ,
A light control device , wherein a refractive index difference between the refractive index of the first uneven shape and the refractive index of the dispersion medium is smaller than 0.2 . In claim 2 ,
A light control device , wherein a refractive index difference between the refractive index of the partition wall and the refractive index of the dispersion medium is smaller than 0.2 . In claim 3 ,
A dimming element in which a difference in refractive index between the refractive index of the second uneven shape and the refractive index of the dispersion medium is smaller than 0.2 . In claim 1 ,
The light control element in which the convex part of said 1st uneven | corrugated shape is colored with black, or is colored with the complementary color of the color at the time of light shielding of the said light control element. In claim 2 ,
The light control element with which the top part of the said partition is colored with black, or is colored with the complementary color of the color at the time of the light-shielding of the said light control element. In claim 3 ,
The light control element with which the convex part of said 2nd uneven | corrugated shape is colored with black, or is colored with the complementary color of the color at the time of light shielding of the said light control element. In claim 2 ,
The light control element in which the material of said 1st uneven | corrugated shape and the material of the said partition are the same. In claim 1,
The light control element, wherein the second electrode is formed in a comb shape on the second substrate. In any one of Claims 1 thru | or 14 .
A plurality of the first uneven shapes are formed,
The plurality of first concavo-convex shapes are stacked on the first electrode,
The light control element in which there are locations where the positions of the convex portions of the plurality of first concavo-convex shapes are shifted when observed from the in-plane normal direction of the first substrate. A dimming element according to any one of claims 1 to 15 ,
A light control device comprising a drive circuit for driving the light control element. A first substrate and a second substrate;
A first electrode on the first substrate and formed between the first substrate and the second substrate;
A second electrode on the second substrate and formed between the first substrate and the second substrate;
A suspension formed between the first electrode and the second electrode;
A first light source and convex shape formed between the first substrate and the suspension;
The suspension includes light control particles and a dispersion medium,
The dimming particles are controlled by applying a voltage to the first electrode and the second electrode,
The first uneven shape has a tapered shape,
The light control particles are rod-shaped,
The aspect ratio of the light control particles is 5 or more and 30 or less,
Applying a DC voltage between the first electrode and the second electrode to place the light control element in a light-shielding state ;
The method of driving a light control element , wherein the light control particles that have reached the first uneven shape fall on the slope of the first uneven shape and are in a random state on the first uneven shape . A first substrate and a second substrate;
A first electrode on the first substrate and formed between the first substrate and the second substrate;
A second electrode on the second substrate and formed between the first substrate and the second substrate;
A suspension formed between the first electrode and the second electrode;
A first light source and convex shape formed between the first substrate and the suspension;
The suspension includes light control particles and a dispersion medium,
The dimming particles are controlled by applying a voltage to the first electrode and the second electrode,
The first uneven shape has a tapered shape,
Applying a DC voltage between the first electrode and the second electrode to place the light control element in a light-shielding state ;
Applying a DC voltage having a polarity opposite to that of the DC voltage application between the first electrode and the second electrode, or applying an AC voltage between the first electrode and the second electrode, A method of driving a light control element that makes the light control element in a transmissive state . A first substrate and a second substrate;
A first electrode on the first substrate and formed between the first substrate and the second substrate;
A second electrode on the second substrate and formed between the first substrate and the second substrate;
A suspension formed between the first electrode and the second electrode;
A method for driving a light control device comprising a first uneven shape formed between the first substrate and the suspension, and a second uneven shape formed between the suspension and the second substrate. Because
The suspension includes light control particles and a dispersion medium,
The dimming particles are controlled by applying a voltage to the first electrode and the second electrode,
The first uneven shape has a tapered shape,
The second uneven shape has a tapered shape,
The second uneven shape is partly flat,
Applying a DC voltage between the first electrode and the second electrode to place the light control element in a light-shielding state ;
A method of driving a light control element, wherein a direct current voltage having a polarity opposite to the direct current voltage application is applied between the first electrode and the second electrode to place the light control element in an intermediate state between a transmission state and a light shielding state. .
A method of driving the light control element.