JP2016025153A - Planar light emitting unit and building component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planar light emitting unit having a function to absorb radio waves.SOLUTION: The planar light emitting unit includes: a planar light emitting part 10 including an organic electroluminescence element which has optical transparency; variation parts 20 and 30 which optically change a light beam from the planar light emitting part 10; and a radio wave absorption part 40 that absorbs radio waves.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a planar light emitter and a building material. In more detail, this invention relates to the planar light-emitting body using an organic electroluminescent element, and a building material using the same.

  In recent years, organic electroluminescence elements (hereinafter also referred to as “organic EL elements”) have been applied to uses such as lighting panels. As an organic EL element, an element having two electrodes as a pair and an organic light emitting layer constituted by one or a plurality of layers disposed between these electrodes and including a light emitting layer is known. One of the pair of electrodes functions as an anode, and the other functions as a cathode. In the organic EL element, by applying a voltage between the anode and the cathode, light emitted from the light emitting layer is extracted to the outside through the light transmissive electrode.

JP2013-201209A

  Since the organic EL element is thin and emits light in a planar shape, the organic EL element is used as a planar light emitter. Various proposals have been made to improve the light emission characteristics of the planar light emitter. For example, Patent Document 1 discloses an organic EL element having an optical layer that changes the traveling direction of light. This organic EL element changes its optical characteristics by providing an optical layer. Then, it is desired to add functions other than the light emission characteristics to the planar light-emitting body having excellent optical characteristics. Examples of other functions include a function of absorbing radio waves.

  This invention is made | formed in view of said point, and it aims at providing the planar light-emitting body which has the function to absorb an electromagnetic wave, and a building material using the same.

  A planar light emitter according to the present invention includes a planar light emitting unit including an organic electroluminescence element having light transmittance, a variable unit that optically changes light from the planar light emitting unit, and a radio wave that absorbs radio waves. An absorption part.

  The building material which concerns on this invention is equipped with the said planar light-emitting body and the holding part holding the said planar light-emitting body.

  The planar light emitter according to the present invention is excellent in optical characteristics between the planar light emitting part and the variable part, and has a function of absorbing radio waves by the radio wave absorbing part.

  Since the building material which concerns on this invention is provided with the holding part holding the said planar light-emitting body, it becomes easy to attach to another member.

FIG. 1 is a schematic cross-sectional view showing an example of a planar light emitter. FIG. 2 is a schematic cross-sectional view showing an example of the radio wave absorber. FIG. 3 is a schematic plan view showing an example of the radio wave absorber. FIG. 4 is a schematic plan view showing an example of the radio wave absorber. FIG. 5 is a schematic plan view showing an example of the radio wave absorber. FIG. 6 is a schematic cross-sectional view showing an example of the radio wave absorber. FIG. 7 is a perspective view showing an example of a building material.

  Hereinafter, modes for carrying out the present invention will be described.

  FIG. 1 shows an example of the planar light emitter 100. The planar light emitter 100 includes a radio wave absorber 40, a light scattering variable unit 20, a planar light emitting unit 10, and a light reflection variable unit 30. In addition, the planar light emitter 100 includes a plurality of substrates 6.

  The planar light emitter 100 has a first surface F1 and a second surface F2. The first surface F <b> 1 is a surface on one side of the planar light emitter 100. The second surface F2 is the surface of the planar light emitter 100 that is opposite to the first surface F1. It can be said that one of the first surface F1 and the second surface F2 is the front surface and the other is the back surface. The second surface F2 is disposed on the side opposite to the first surface F1.

  The 1st surface F1 is comprised so that the light from the planar light emission part 10 may be taken out. The first surface F1 may be called a main light emitting surface. It can be said that the 1st surface F1 is a surface of the direction which wants to obtain illumination. The planar light-emitting body 100 is formed so that light emission can be taken out to one of the front and back surfaces. The surface of the planar light emitting unit 10 on which light is to be extracted is the first surface F1. The first surface F1 may be called a main light extraction surface. The reason why the first surface F1 is mainly used is that the second surface F2 may serve as a subsidiary and the light from the planar light emitting unit 10 may be extracted from the second surface F2. However, even when light is extracted from both surfaces, it is preferable that more light is extracted from the first surface F1 than from the second surface F2. In the planar light emitter 100, a structure is formed in which light from the planar light emitting unit 10 is more likely to be emitted to the first surface F1 side than the second surface F2. The planar light emitting unit 10 has a structure that easily emits light to the first surface F1 side rather than the second surface F2.

  The radio wave absorber 40, the light scattering variable unit 20, the planar light emitting unit 10, and the light reflection variable unit 30 are disposed in the thickness direction between the first surface F1 and the second surface F2. The light reflection variable unit 30 is disposed on the second surface F2 side with respect to the planar light emitting unit 10 and the light scattering variable unit 20. The planar light emitter 100 may be arranged in the order of the radio wave absorber 40, the light scattering variable unit 20, the planar light emitting unit 10, and the light reflection variable unit 30 from the first surface F1 side. . Further, the planar light emitter 100 may be arranged in the order of the radio wave absorber 40, the planar light emitter 10, the light scattering variable unit 20, and the light reflection variable unit 30. In any planar light emitting body 100, the light scattering variable portion 20 is disposed on the second surface F2 side. Therefore, the planar light emitter 100 can emit light with high efficiency, and the planar light emitter 100 having excellent optical characteristics can be obtained. The radio wave absorber 40 may be provided not only on the first surface F1 of the planar light emitter 100 but also on the second surface F2. Further, the radio wave absorber 40 is provided between the light scattering variable unit 20 and the planar light emitting unit 10, or between the planar light emitting unit 10 and the light reflecting variable unit 30, or the light scattering variable unit 20 and the light reflecting unit. It may be provided between the variable parts 30. Further, a plurality of radio wave absorbers 40, light scattering variable units 20, planar light emitting units 10, and light reflection variable units 30 may be provided.

  The planar light emitter 100 of FIG. 1 is arranged in the order of the radio wave absorber 40, the light scattering variable unit 20, the planar light emitting unit 10, and the light reflection variable unit 30 from the first surface F1 side. The radio wave absorber 40 is formed on the surface of the substrate 6a. The light scattering variable unit 20 is disposed between the substrate 6a and the substrate 6b. The planar light emitting unit 10 is disposed between the substrate 6b and the substrate 6c. The light reflection variable unit 30 is disposed between the substrate 6c and the substrate 6d. The substrate 6 b serves as the substrate 6 that supports or seals the light scattering variable portion 20 and the substrate 6 that supports or seals the planar light emitting portion 10. A substrate 6 b is disposed between the light scattering variable unit 20 and the planar light emitting unit 10. The substrate 6 c serves as the substrate 6 that supports or seals the planar light emitting unit 10 and the substrate 6 that supports or seals the light reflection variable unit 30. A substrate 6 c is disposed between the planar light emitting unit 10 and the light reflection variable unit 30. No gap is provided between the light scattering variable portion 20 and the planar light emitting portion 10. No gap is provided between the planar light emitting unit 10 and the light reflection variable unit 30. The void is a laminar gap. If there is no gap, the number of interfaces where light can be reflected or refracted can be reduced, so that more light from the planar light emitting unit 10 can be extracted. In addition, when there is a gap, the light extraction property may be deteriorated due to light interference. However, when there is no void, the light interference can be suppressed and the light extraction property can be improved.

  The planar light emitter 100 has a plurality of electrodes 5. The plurality of electrodes 5 are light transmissive. Thereby, the planar light emitter 100 has high optical characteristics. The electrode 5 functions as an electrode for driving the planar light emitter 100. The planar light emitter 100 can exhibit a state of being transparent as a whole.

  The electrode 5 is composed of a transparent conductive layer. As a material for the transparent conductive layer, for example, a transparent metal oxide, a conductive particle-containing resin, a metal thin film, or the like is used. As a preferable material for the electrode 5 having optical transparency, transparent metal oxides such as ITO and IZO are exemplified. The electrode 5 made of a transparent metal oxide is preferably used for the electrode 5 of the planar light emitting unit 10. The electrode 5 may be a layer containing silver nanowires or a transparent metal layer such as thin film silver. Alternatively, a transparent metal oxide layer and a metal layer may be laminated.

  The electrode 5 preferably has a heat shielding effect. Thereby, heat transmission in the planar light emitting body 100 is suppressed, and heat insulation is improved. The planar light-emitting body 100 with high heat insulation is advantageous for building materials and the like. Since the transparent metal oxide can have a heat shielding effect, it is useful as a material for the electrode 5. In particular, ITO has a high heat shielding effect.

  The electrode 5 may be configured to be electrically connected to an external power source. The planar light-emitting body 100 may have an electrode pad, an electrical connection part that electrically collects the electrode pad, and the like in order to connect to the power supply 50. The electrical connection part may be constituted by a plug or the like.

  The electrode 5 is connected to a power source 50 by a wiring 53. When an external power source is used as the power source 50, the planar light emitter 100 may be configured by a part up to the middle of the wiring 53 (part up to a plug or the like). When the power source 50 is an internal power source, the planar light emitter 100 may include the power source 50.

  The planar light emitter 100 preferably includes a plurality of substrates 6. The plurality of substrates 6 are light transmissive. Thereby, the planar light emitter 100 has high optical characteristics. The substrate 6 can function as a substrate for supporting each layer of the planar light emitter 100. The substrate 6 can function as a substrate for sealing each layer of the planar light emitter 100. The plurality of substrates 6 are arranged in the thickness direction.

  The planar light emitting body 100 is preferably such that the planar light emitting unit 10, the light scattering variable unit 20, and the light reflection variable unit 30 are disposed between two opposing substrates 6. Thereby, the planar light emitting unit 10, the light scattering variable unit 20, and the light reflection variable unit 30 are protected by the substrate 6. The planar light emitter 100 may have one or a plurality of other substrates 6 between two opposing substrates 6 arranged at the end in the thickness direction.

  The plurality of substrates 6 are bonded at end portions. Adhesion is performed by an adhesive. An adhesive portion 7 is formed from an adhesive. A gap is provided between adjacent substrates 6 in the thickness direction. The layers constituting each part of the planar light emitter 100 are disposed in the gaps between the substrates 6. The gap between the adjacent substrates 6 is provided with the bonding portion 7 as a spacer. It is preferable that the adhesion part 7 has moisture resistance. Thereby, deterioration of the planar light emitter 100 is suppressed.

  Resin can be used as the material of the bonding portion 7. As the resin, a thermosetting resin, an ultraviolet curable resin, or the like is used. The bonding portion 7 may include a spacer material such as particles. Thereby, the thickness of the gap between the substrates 6 is easily ensured.

  Here, the thickness direction is a vertical direction in FIG. The thickness direction may be the same as the direction in which the layers are stacked. The thickness direction may be a direction perpendicular to the surface of the substrate 6. In FIG. 1, it can be considered that each layer of the planar light emitter 100 extends in the horizontal direction and the direction perpendicular to the paper surface. In FIG. 1, the surface direction may be referred to as a horizontal direction and a direction perpendicular to the paper surface.

  As the substrate 6, for example, a glass substrate, a resin substrate, or the like is used. When the substrate 6 is composed of a glass substrate, since the glass is highly transparent, it is easy to obtain the planar light emitter 100 having excellent optical characteristics. Further, since glass has low moisture permeability, it is easy to suppress moisture from entering the sealed region. When the substrate 6 is formed of a resin substrate, since the resin is difficult to break, it is easy to obtain a safe planar light emitter 100 in which scattering at the time of breakage is suppressed. Moreover, when the board | substrate 6 is comprised with a resin substrate, the flexible planar light-emitting body 100 is easy to be obtained.

  Of the plurality of substrates 6, the two substrates 6 arranged on the outside are preferably glass substrates. Thereby, the planar light-emitting body 100 with excellent optical characteristics can be easily obtained. All of the plurality of substrates 6 may be glass substrates. In that case, the optical conditions of the planar light emitter 100 can be easily controlled, and the optical characteristics of the planar light emitter 100 are enhanced. Any one or more of the inner substrates 6 may be a resin substrate. In that case, scattering at the time of destruction of the planar light emitter 100 is easily suppressed, and a safe planar light emitter 100 is obtained. The surface of the substrate 6 may be covered with an antifouling material. In that case, the contamination of the surface of the substrate 6 is reduced. The antifouling material is preferably coated on the outer surface of the substrate 6 disposed outside. Moreover, when the board | substrate 6 is a resin substrate, the surface may be coat | covered with the moisture proof material. In that case, the sealing performance of the planar light emitter 100 is enhanced.

  The radio wave absorber 40 has a function of absorbing radio waves. Here, the radio wave may be an electromagnetic wave having a longer wavelength (lower frequency) than visible light. For example, the radio wave absorber 40 preferably absorbs radio waves of 3 Hz to 300 GHz. When the radio wave absorber 40 has a function of absorbing radio waves of 300 MHz to 30 GHz, the radio wave absorber 40 can absorb radio waves of a home wireless LAN. As a result, in a house where the planar light emitter 100 is used as a building material or the like, it is difficult for radio waves of a home wireless LAN to leak to the outside, and personal information is easily protected by the planar light emitter 100. In addition, when the planar light emitter 100 is used as a building material in a hospital or factory, obstruction radio waves from the outside are easily absorbed by the radio wave absorber 40. Accordingly, intrusion of disturbing radio waves from the outside to a hospital or factory is suppressed or prevented, and leakage of information in the hospital or factory is reduced.

  The radio wave absorber 40 is formed of a mixture of carbon fibers 41 and a resin material 42 as shown in FIG. When the radio wave passes through the radio wave absorber 40, it is converted into heat by the electrical resistance (ohm loss) and dielectric loss of the carbon fiber 41 and absorbed. The radio wave absorber 40 is held by being adhered to the substrate 6 by the resin material 42.

  The carbon fibers 41 may be single fibers or filaments (bundles of single fibers), but are preferably carbon coils. The carbon coil is formed by winding a single fiber in a spiral shape. The carbon coil has a larger amount of carbon per unit volume than a single fiber or filament, and in this case, the radio wave absorption performance per unit amount of the radio wave absorber 40 is improved. A carbon coil having a size called a carbon microcoil or a carbon nanocoil is used. For example, a carbon coil having a diameter of 0.1 to 10 μm and a length of 0.01 to 0.2 mm can be used. With a carbon coil of this size, the dispersion in the resin material 42 is good, and a uniform radio wave absorber 40 is easily formed.

  The resin material 42 has electrical insulation. As the resin material 42, an acrylic resin, an epoxy resin, or the like can be used. The resin material 42 preferably has translucency, and more preferably is transparent. The content ratio of the carbon fiber 41 and the resin material 42 in the radio wave absorber 40 may be within a range in which the radio wave absorption performance of the radio wave absorber 40 is obtained and the translucency of the radio wave absorber 40 is not impaired. For example, it is preferable that the carbon fiber 41 is contained in a ratio of 1 to 50 parts by mass with respect to 100 parts by mass of the resin material 42. Moreover, it is more preferable that the carbon fiber 41 is contained at a rate of 5 to 40 parts by mass with respect to 100 parts by mass of the resin material 42, and at a rate of 10 to 20 parts by mass with respect to 100 parts by mass of the resin material 42. More preferably, carbon fiber 41 is contained. The content ratio of the carbon fiber 41 and the resin material 42 in the radio wave absorber 40 can be appropriately set in consideration of the radio wave absorption performance and translucency of the radio wave absorber 40.

  The radio wave absorber 40 is formed of a plurality of linear portions 43. The linear portion 43 is formed in an elongated linear shape from a mixture of the carbon fiber 41 and the resin material 42. In the radio wave absorber 40, a plurality of linear portions 43 are formed side by side on the surface of the substrate 6 (the outermost substrate 6a). For example, as shown in FIG. 3, the radio wave absorber 40 is formed in a lattice shape in a plan view. In this case, the radio wave absorber 40 is formed by arranging a plurality of linear portions 43 vertically and horizontally. The linear portion 43 is formed so that its longitudinal direction is parallel to the edge of the substrate 6. The radio wave absorber 40 is formed in a cross-hatched shape (diagonal lattice shape) in a plan view as shown in FIG. 4, for example. In this case, the radio wave absorber 40 is formed by arranging a plurality of linear portions 43 obliquely from side to side. The linear portion 43 is formed such that its longitudinal direction is inclined with respect to the edge of the substrate 6. The radio wave absorber 40 is formed in a shape in which a lattice shape and a cross hatching shape are combined in a plan view as shown in FIG. In this case, the radio wave absorber 40 is formed by arranging a plurality of linear portions 43 side by side in the vertical and horizontal directions and the left and right sides. The plurality of linear portions 43 includes a linear portion 43 that is parallel to the edge of the substrate 6 and a linear portion 43 that is inclined with respect to the edge of the substrate 6. Although the carbon fibers 41 are dispersed and contained in the resin material 42 of the linear portion 43, the carbon fibers 41 may be regularly arranged in the resin material 42 by applying a voltage or the like. For example, the carbon fibers 41 may be oriented so that the longitudinal direction thereof coincides with the longitudinal direction of the linear portion.

  The linear portion 43 is formed in a semicircular cross section, but is not limited thereto, and may be formed in a circle, a triangle, or a quadrangle. The width dimension of the linear portion 43 can be appropriately set according to the frequency of the radio wave absorbed by the radio wave absorber 40. The width dimension of the linear portion 43 is set to, for example, 2 to 15 μm, preferably 5 to 10 μm. The interval between the adjacent parallel linear portions 43 can also be set as appropriate according to the frequency of the radio wave absorbed by the radio wave absorber 40. The space | interval of the adjacent parallel linear part 43 is set to 5-80 mm, for example, Preferably it is 20-50 mm.

  The linear portion 43 is formed by a coating method or the like. For example, the mixture of the carbon fiber 41 and the resin material 42 is applied to the surface of the substrate 6 by a known application method such as ink jet printing, screen printing, or electrostatic coating method. When the resin material 42 of the mixture is in a liquid or molten state, the linear portion 43 is formed by being cured or solidified after application.

  By the way, as the radio wave absorber, as shown in FIG. 6, a metal plate 45 provided with a large number of metal projections 46 may be considered. In this case, however, weight reduction, transparency ensuring, and thickness reduction are possible. It cannot be done easily. Further, although a radio wave absorbing portion in which a magnetic radio wave absorbing material is applied to the surface of the substrate 6 can be considered, it is not easy to reduce the weight and ensure transparency. Furthermore, although a radio wave absorbing portion in which an acrylic resin and a transparent resistance film are laminated on the surface of the substrate 6 can be considered, it is difficult to ensure transparency. On the other hand, the radio wave absorber 40 having the above-described configuration can be easily reduced in weight, ensured transparency, and reduced in thickness.

  The planar light emitting unit 10 is composed of a light-transmitting organic EL element. The organic EL element may be transparent. The organic EL element may be translucent. In order to enhance optical characteristics, the organic EL element is preferably transparent. A moisture-proof material may be coated on the organic EL element. In this case, the sealing performance can be improved. It is preferable that the moisture-proof material is transparent.

  The planar light emitting unit 10 includes a pair of electrodes 5a and 5b, and an organic light emitting layer 1 disposed between the pair of electrodes 5a and 5b. An organic EL element is an element which has the structure by which the organic light emitting layer 1 is arrange | positioned between the electrode 5a and the electrode 5b. By forming the planar light emitting unit 10 with an organic EL element, a thin and transparent light emitting body having excellent optical characteristics is formed. The organic light emitting layer 1 has light transmittance. The electrodes 5a and 5b are light transmissive. Therefore, at the time of light emission, the light emitted from the organic light emitting layer 1 is emitted to both sides in the thickness direction. Further, when light is not emitted, light is transmitted from one side to the other side.

  The electrode 5a and the electrode 5b are a pair of electrodes. One of the electrode 5a and the electrode 5b constitutes an anode, and the other constitutes a cathode. The electrode 5a is disposed on the first surface F1 side, and the electrode 5b is disposed on the second surface F2 side. The electrode 5a is an electrode on the light extraction side. Although FIG. 1 shows an example in which the electrode 5a is constituted by a cathode and the electrode 5b is constituted by an anode, the electrode 5a may be constituted by an anode and the electrode 5b may be constituted by a cathode.

  The organic light emitting layer 1 is a layer having a function of causing light emission, and is appropriately selected from a hole injection layer, a hole transport layer, a light emitting layer (a layer containing a light emitting material), an electron transport layer, an electron injection layer, an intermediate layer, and the like. It can be constituted by a plurality of functional layers. Of course, the organic light emitting layer 1 may be composed of a single light emitting layer. In the organic EL element, voltage is applied to the electrodes 5a and 5b, and electricity flows between them, whereby holes and electrons are combined in the organic light emitting layer 1 (light emitting material-containing layer) to emit light.

  The planar light emitting unit 10 is disposed between adjacent substrates 6. The planar light emitting unit 10 is sealed by being disposed between the two substrates 6. By the sealing, the deterioration of the organic light emitting layer 1 is suppressed. The two substrates 6 are a pair. Usually, an organic EL element is formed by lamination. At that time, a formation substrate for stacking is required. The formation substrate is formed of at least one of the pair of substrates 6. The substrate 6 facing the formation substrate is a sealing substrate. The sealing substrate is formed of the pair of substrates 6 that is not the formation substrate.

  The planar light emitting unit 10 emits light in the organic light emitting layer 1 when electricity flows between the electrodes 5a and 5b. The electrode 5 a and the electrode 5 b are electrically connected to the power source 50 through a wiring 53. By supplying power from the power supply 50, a current flows through the organic light emitting layer 1. The power source 50 is constituted by a DC power source 51. In the organic EL element, the direction of current is generally one direction. Stable light emission of the planar light emitting unit 10 can be obtained by the DC power source 51. FIG. 1 shows a state in which the electrode 5a serves as a cathode and is electrically connected to the cathode of the DC power supply 51, and the electrode 5b serves as an anode and is electrically connected to the anode of the DC power supply 51. However, the direction of the current may be reversed. The emission color of the planar light emitting unit 10 may be white, blue, green, or red. Of course, it may be an intermediate color between blue and green or green and red. Further, the color may be adjusted by the applied current.

  The light scattering variable part 20 is a part where the light scattering property changes. The light scattering variable unit 20 is configured to be capable of changing the degree of light scattering. The fact that the degree of light scattering can be changed may mean that the high scattering state and the low scattering state can be changed. Alternatively, the fact that the degree of light scattering property can be changed may mean that the state having light scattering property and the state having no light scattering property can be changed. If the degree of light scattering can be changed, the optical state can be changed, and the planar light-emitting body 100 having excellent optical characteristics can be obtained. The light scattering variable portion 20 may be formed in a layer shape.

  The high scattering state is a state having high light scattering properties. The high scattering state is, for example, a state in which light incident from one surface changes its traveling direction into various directions due to scattering and is dispersed and emitted to the other surface. The high scattering state may be a state in which an object appears blurry when an object existing from one surface side to the other surface side is viewed. The highly scattering state can be a translucent state. When the light scattering variable unit 20 exhibits light scattering properties, the light scattering variable unit 20 functions as a scattering layer that scatters light.

  The low scattering state is a state where light scattering property is low or light scattering property is not present. The low scattering state is, for example, a state in which light incident from one surface is emitted to the other surface while maintaining the traveling direction as it is. The low scattering state may be a state where an object can be clearly visually recognized when an object existing on the other surface side is viewed from one surface side. The low scattering state can be a transparent state.

  The light scattering variable unit 20 exhibits a light scattering property between a high scattering state having a high light scattering property, a low scattering state having a low light scattering property or no light scattering property, and a high scattering state and a low scattering state. It is preferable that it is comprised so that it can have a state. The ability to exhibit light scattering properties between the high scattering state and the low scattering state can impart moderate light scattering properties, so that the optical state can be varied highly and optically. The characteristics can be further improved. Here, a state that exhibits light scattering between the high scattering state and the low scattering state is referred to as a medium scattering state.

  The medium scattering state may have at least one scattering state between the high scattering state and the low scattering state. For example, if the light scattering property can be changed by switching between three states of a high scattering state, a medium scattering state, and a low scattering state, the optical characteristics are improved. It is a preferable aspect that the medium scattering state has a plurality of states in which the degree of scattering is in a plurality of stages between the high scattering state and the low scattering state. Thereby, since the degree of scattering is in a plurality of stages, the optical characteristics can be further improved. For example, if the light scattering property can be changed in a stepwise manner by switching a plurality of states of a high scattering state, a plurality of medium scattering states, and a low scattering state, the optical characteristics are improved. It is a preferable aspect that the medium scattering state is configured to continuously change from the high scattering state to the low scattering state between the high scattering state and the low scattering state. Thereby, since the degree of scattering changes continuously, the optical state can be changed with high variation, and the optical characteristics can be further improved. For example, if the light scattering property can be changed between a high scattering state and a low scattering state so as to exhibit the desired light scattering property, an intermediate state can be created, so that the optical characteristics are improved. . When the light scattering variable unit 20 has a medium scattering state, the light scattering variable unit 20 is preferably configured to maintain the medium scattering state.

  The light scattering variable unit 20 may scatter at least a part of visible light. The light scattering variable unit 20 is preferably one that scatters all visible light. Of course, the light scattering variable unit 20 may scatter infrared rays or scatter ultraviolet rays.

  The light scattering variable unit 20 is preferably configured so as to be able to change at least one of the scattering amount and the scattering direction. The change in the scattering amount and the scattering direction may be performed in a medium scattering state. Changing the amount of scattering means changing the intensity of scattering. Changing the scattering direction means changing the directionality of scattering. When the amount of scattering and the direction of scattering change, for example, when an object on the opposite side of the planar light emitter 100 is visually recognized, the intensity of ambiguity (blurring) of the object changes. Therefore, it is possible to change the appearance of an object through the planar light emitter 100 when no light is emitted, or to control the light distribution of the light generated by the planar light emitting unit 10 during light emission. The optical characteristics of the planar light emitter 100 are improved.

  In a state where the light scattering variable portion 20 exhibits light scattering properties, the light scattering variable portion 20 has a scattering property for light in a direction from the second surface F2 to the first surface F1 rather than light in a direction from the first surface F1 to the second surface F2. Is preferably high. Thereby, since the light from the planar light emission part 10 can be scattered more, an optical characteristic can be improved. Of course, the light scattering variable portion 20 is in a state of exhibiting light scattering properties, and includes light in a direction from the first surface F1 toward the second surface F2 and light in a direction from the second surface F2 toward the first surface F1. The light scattering properties may be the same. Alternatively, the light scattering variable unit 20 exhibits light scattering properties, and light in a direction from the first surface F1 toward the second surface F2 is light in a direction from the second surface F2 toward the first surface F1. The light scattering property may be higher than that.

  The light scattering variable portion 20 can be formed with an appropriate structure that can change the degree of light scattering. The light scattering variable unit 20 may be an electric field modulation, a temperature modulation, or the like. Electric field modulation is a method in which the light scattering property is changed by applying an electric field. Temperature modulation is a method in which the light scattering property changes with temperature.

  The planar light emitter 100 is preferably configured so that the light scattering property of the light scattering variable portion 20 can be controlled. For example, in the temperature modulation method, the light scattering property may change due to a change in the external temperature, but if the light scattering property depends on the external temperature, there is a possibility that desired optical characteristics cannot be obtained. Therefore, it is preferable that the light scattering property is controlled. In the temperature modulation, the temperature can be controlled by a heater or a cooler. However, temperature control is not easier than electric field control. Therefore, the light scattering variable unit 20 is preferably electric field modulation. Since the light scattering property can be easily changed by the electric field, the optical characteristics can be improved. In each embodiment, the electric field modulation light scattering variable unit 20 is used. The electric field modulation light scattering variable unit 20 will be described below.

  The light scattering variable unit 20 is configured to be capable of transmitting light. In the high scattering state, the light scattering variable unit 20 may be translucent. In the low scattering state, the light scattering variable unit 20 may be transparent. In the medium scattering state, the light scattering variable unit 20 may be translucent with higher transparency than in the high scattering state.

  The light scattering variable unit 20 includes a pair of electrodes 5x and 5y and a light scattering variable layer 2 disposed between the pair of electrodes 5x and 5y. In the pair of electrodes 5x and 5y, the electrode 5x is disposed on the first surface F1 side, and the electrode 5y is disposed on the second surface F2 side. The light scattering variable unit 20 has a configuration in which the light scattering variable layer 2 is disposed between the electrode 5x and the electrode 5y. By configuring the light scattering variable portion 20 with the light scattering variable layer 2, a thin light scattering structure with excellent optical characteristics can be formed. The light scattering variable layer 2 is a layer whose light scattering property changes. The light scattering variable layer 2 has at least a high scattering state and a low scattering state. The light scattering variable layer 2 preferably has a medium scattering state. The electrode 5x and the electrode 5y have optical transparency. Therefore, when the light scattering variable layer 2 has a light scattering property, the light incident on the light scattering variable portion 20 can be scattered. In addition, when the light scattering variable layer 2 is not in a light scattering state, the light incident on the light scattering variable portion 20 can be emitted as it is.

  The light scattering variable unit 20 is disposed between the adjacent substrates 6. The light scattering variable portion 20 is sealed between the two substrates 6 by being disposed. By sealing, the light-scattering variable layer 2 is hold | maintained and the deterioration is further suppressed. The two substrates 6 are a pair. Usually, the light scattering variable portion 20 is formed by stacking. At that time, a formation substrate for stacking is required. The formation substrate is formed of at least one of the pair of substrates 6. The substrate 6 facing the formation substrate is a sealing substrate. The sealing substrate is formed of the pair of substrates 6 that is not the formation substrate.

  The light scattering variable portion 20 changes the degree of light scattering in the light scattering variable layer 2 by applying a voltage between the electrode 5x and the electrode 5y. The electrode 5x and the electrode 5y are electrically connected to the power source 50 through a wiring 53. By supplying power from the power supply 50, a voltage is applied to the light scattering variable unit 20. The power supply 50 of the light scattering variable unit 20 is constituted by an AC power supply 52. There are many materials whose light scattering property changes due to an electric field, and it becomes impossible to maintain the light scattering state at the time of voltage application as time passes from the start of voltage application. In the AC power supply 52, a voltage can be alternately applied in both directions, and a voltage can be applied substantially continuously by changing the direction of the voltage. Therefore, stable light scattering can be obtained by the AC power supply 52. The AC waveform is preferably a rectangular wave. Thereby, the amount of voltage to be applied is likely to be constant, so that it becomes possible to stabilize the light scattering property. Of course, the alternating current may be a pulse. Note that the intermediate scattering state can be formed by controlling the amount of voltage applied.

  As the material of the light scattering variable layer 2, a material whose molecular orientation is changed by electric field modulation is used. For example, a liquid crystal material etc. are mentioned. As a material of the light scattering variable layer 2, it is preferable to use a polymer dispersed liquid crystal. In the polymer dispersed liquid crystal, since the liquid crystal is held by the polymer, the stable light scattering variable layer 2 is formed. The polymer dispersed liquid crystal is called PDLC. In addition, as a material of the light-scattering variable layer 2, the solid substance from which light-scattering property changes with an electric field is also used preferably.

  The polymer dispersed liquid crystal may be composed of a resin part and a liquid crystal part. The resin part is formed of a polymer. It is preferable that the resin part has optical transparency. Thereby, the light scattering variable portion 20 can be made light transmissive. The resin portion can be formed of a thermosetting resin, an ultraviolet curable resin, or the like. The liquid crystal part is a part where the liquid crystal structure is changed by an electric field. A nematic liquid crystal or the like is used for the liquid crystal part. The polymer-dispersed liquid crystal is a preferred embodiment having a structure in which the liquid crystal portion is present in a dot shape in the resin portion. The polymer dispersed liquid crystal may have a sea-island structure in which the resin portion forms the sea and the liquid crystal portion forms the island. The polymer-dispersed liquid crystal is a preferable embodiment in which the liquid crystal part is irregularly connected in a mesh shape in the resin part. Of course, the polymer-dispersed liquid crystal may have a structure in which the resin part is present in a dot shape in the liquid crystal part, or in which the resin part is irregularly connected in a mesh shape in the liquid crystal part.

  The light scattering variable unit 20 is preferably in a light scattering state when no voltage is applied and in a light transmission state when a voltage is applied. Such control can be performed in the polymer dispersed liquid crystal. This is because the alignment of liquid crystals can be made uniform by applying a voltage. In the polymer-dispersed liquid crystal, the light scattering variable portion 20 that is thin and has high scattering properties can be formed. Of course, the light scattering variable unit 20 may be in a light transmission state when no voltage is applied and in a light scattering state when a voltage is applied.

  The light scattering variable layer 2 is a preferred embodiment in which the light scattering state is maintained when a voltage is applied. Thereby, a voltage is applied when it is desired to change the light scattering state, and it is not necessary to apply a voltage when it is not, so that the power efficiency is increased. The property of maintaining the light scattering state is called hysteresis. This property may be called memory property (memory property). Hysteresis can be exerted by applying a voltage higher than a predetermined voltage. The longer the time during which the light scattering state is maintained, the better. For example, it is preferably 1 hour or longer, more preferably 3 hours or longer, further preferably 6 hours or longer, more preferably 12 hours or longer, more preferably 24 hours or longer. More preferable.

The light reflection variable portion 30 is a portion where the light reflectivity changes. The light reflection variable unit 30 is configured so that the degree of light reflectivity can be changed. The fact that the degree of light reflectivity can be changed may mean that the high reflection state and the low reflection state can be changed. Alternatively, the fact that the degree of light reflectivity can be changed may mean that the state having light reflectivity and the state having no light reflectivity can be changed. If the degree of light reflectivity can be changed, the optical state can be changed, and the planar light-emitting body 100 having excellent optical characteristics can be obtained. The light reflection variable portion 30 may be formed in a layer shape.

  A highly reflective state is a state with high light reflectivity. The high reflection state is, for example, a state in which light incident on one surface is changed to the opposite direction due to reflection and is emitted to the incident side. The highly reflective state may be a state in which an object existing on one surface side from the other surface side cannot be visually recognized. The high reflection state may be a state in which an object existing on the same surface side is visually recognized when the light reflection variable unit 30 is viewed from one surface side. The highly reflective state can be a mirror state. When the light reflection variable unit 30 exhibits light reflectivity, the light reflection variable unit 30 functions as a reflection layer that reflects light.

  The low reflection state is a state where the light reflectivity is low or there is no light reflectivity. The low reflection state is, for example, a state in which light incident from one surface is emitted to the other surface while maintaining the traveling direction as it is. The low reflection state may be a state in which an object can be clearly visually recognized when an object existing on the other surface side is viewed from one surface side. The low reflection state can be a transparent state.

  The light reflection variable unit 30 exhibits a light reflection property between a high reflection state with high light reflection property, a low reflection state with low light reflection property or no light reflection property, and a high reflection state and a low reflection state. It is preferable that it is comprised so that it can have a state. The ability to exhibit light reflectivity between the high reflection state and the low reflection state can provide moderate light reflectivity, so that the optical state can be varied highly and optically. The characteristics can be further improved. Here, a state that exhibits light reflectivity between the high reflection state and the low reflection state is referred to as a medium reflection state.

  The medium reflection state may have at least one reflection state between the high reflection state and the low reflection state. For example, if the light reflectivity can be changed by switching between three states of a high reflection state, a medium reflection state, and a low reflection state, the optical characteristics are improved. It is preferable that the intermediate reflection state has a plurality of states in which the degree of reflectivity is in a plurality of stages between the high reflection state and the low reflection state. Thereby, since the degree of reflectivity is in a plurality of stages, the optical characteristics of the planar light emitter 100 are further enhanced. For example, if the light reflectivity can be changed stepwise by switching between a plurality of states of a high reflection state, a plurality of medium reflection states, and a low reflection state, the optical characteristics are improved. It is a preferable aspect that the intermediate reflection state is configured to continuously change from the high reflection state to the low reflection state between the high reflection state and the low reflection state. Thereby, since the degree of reflectivity changes continuously, the optical state can be changed with high variations, and the optical characteristics can be further improved. For example, if the light reflectivity can be changed between a high reflection state and a low reflection state so as to exhibit the desired light reflectivity, an intermediate state can be created, so that the optical characteristics are improved. . When the light reflection variable unit 30 has the intermediate reflection state, the light reflection variable unit 30 is preferably configured to maintain the intermediate reflection state.

  The light reflection variable unit 30 may reflect at least a part of visible light. It is preferable that the light reflection variable unit 30 reflects all visible light. The light reflection variable unit 30 may reflect infrared rays. The light reflection variable unit 30 may reflect ultraviolet rays. When the light reflection variable portion 30 reflects all visible light, ultraviolet light, and infrared light, the planar light emitting body 100 having excellent optical characteristics and stable can be obtained.

  The light reflection variable unit 30 is preferably configured to be capable of changing the shape of the reflection spectrum. The change in the reflection spectrum may be performed in the middle reflection state. The change in the shape of the reflection spectrum means that the spectrum shape of the light incident on the light reflection variable unit 30 and the light reflected by the light reflection variable unit 30 are different. The reflection spectrum is changed by changing the reflection wavelength. For example, the shape of the reflection spectrum changes by strongly reflecting only blue light, strongly reflecting only green light, or strongly reflecting only red light. When the reflection spectrum changes, the color of light extracted from the planar light emitting unit 10 changes. Therefore, toning (color adjustment) can be performed, and the optical characteristics of the planar light emitter 100 are improved.

  The light reflection variable unit 30 is preferably configured so as to be able to reflect light without changing the shape of the reflection spectrum. In that case, since there is no change in the spectrum between the incident light and the reflected light, the degree of reflection can be simply weakened. When it is possible to control the intensity of the reflectivity, light control (brightness adjustment) can be performed, and the optical characteristics of the planar light emitter 100 are improved.

  In a state where the light reflection variable unit 30 exhibits light reflectivity, the light reflection variable unit 30 is more reflective to light in the direction from the first surface F1 to the second surface F2 than in the direction from the second surface F2 to the first surface F1. Is preferably high. Thereby, since the light from the planar light emission part 10 can be reflected more, an optical characteristic can be improved. Of course, the light reflection variable unit 30 exhibits light reflectivity between the light in the direction from the first surface F1 toward the second surface F2 and the light in the direction from the second surface F2 toward the first surface F1. The light reflectivity may be the same. Alternatively, the light reflection variable unit 30 exhibits light reflectivity, and light in the direction from the second surface F2 toward the first surface F1 is light in the direction from the first surface F1 toward the second surface F2. The light reflectivity may be higher than that.

  The light reflection variable portion 30 can be formed with an appropriate structure that can change the degree of light reflectivity. The light reflection variable unit 30 may be an electric field modulation, a temperature modulation, a gas modulation, or the like. Electric field modulation is a method in which light reflectivity changes by applying an electric field. Temperature modulation is a method in which light reflectivity changes with temperature. Gas modulation is a method in which the light reflectivity is changed by supplying a gas.

  The planar light emitter 100 is preferably configured so that the light reflectivity of the light reflection variable portion 30 can be controlled. For example, in the temperature modulation method, the light reflectivity may change due to a change in the external temperature, but if the light reflectivity depends on the external temperature, there is a possibility that desired optical characteristics cannot be obtained. Therefore, it is preferable that the light reflectivity is controlled. In the temperature modulation, the temperature can be controlled by a heater or a cooler. However, temperature control is not easier than electric field control. Gas modulation can be controlled by the presence or absence of gas supply. However, since gas supply requires gas piping and the like, the structure is likely to be complicated, and it is not easier than controlling the electric field. In addition, when a gas that is flammable or explosive, such as hydrogen gas, is used as a gas for gas modulation, a safety problem also occurs. Therefore, it is preferable that the light reflection variable unit 30 is electric field modulation. Since the light reflectivity can be easily changed by the electric field, the optical characteristics can be improved. In each embodiment, an electric field modulation light reflection variable unit 30 is used. The electric field modulation light reflection variable unit 30 will be described below.

  The light reflection variable unit 30 is configured to be capable of transmitting light. In the high reflection state, the light reflection variable unit 30 may be opaque. In the high reflection state, the light reflection variable portion 30 is preferably in a mirror shape. In the low reflection state, the light reflection variable unit 30 may be transparent. In the intermediate reflection state, the light reflection variable unit 30 may be translucent. At this time, a part of the light may be reflected and a part of the light may be transmitted.

The light reflection variable unit 30 includes a pair of electrodes 5p and 5q, and a light reflection variable layer 3 disposed between the pair of electrodes 5p and 5q. In the pair of electrodes 5p and 5q, the electrode 5p is disposed on the first surface F1 side, and the electrode 5q is disposed on the second surface F2 side. The light reflection variable section 30 has a configuration in which the light reflection variable layer 3 is disposed between the electrode 5p and the electrode 5q. By configuring the light reflection variable portion 30 with the light reflection variable layer 3, it is possible to form a thin light reflection structure with excellent optical characteristics. The light reflection variable layer 3 is a layer whose light reflectivity changes. The light reflection variable layer 3 has at least a high reflection state and a low reflection state. The light reflection variable layer 3 preferably has a middle reflection state. The electrode 5p and the electrode 5q are light transmissive. Therefore, when the light reflection variable layer 3 has a light reflectivity, the light incident on the light reflection variable portion 30 can be reflected. Further, when the light reflection variable layer 3 is not in a light reflective state, the light incident on the light reflection variable portion 30 can be emitted as it is.

  The light reflection variable unit 30 is disposed between the adjacent substrates 6. The light reflection variable portion 30 is disposed between the two substrates 6 to be sealed. By sealing, the light reflection variable layer 3 is held, and its deterioration is further suppressed. The two substrates 6 are a pair. Usually, the light reflection variable portion 30 is formed by lamination. At that time, a formation substrate for stacking is required. The formation substrate is formed of at least one of the pair of substrates 6. The substrate 6 facing the formation substrate is a sealing substrate. The sealing substrate is formed of the pair of substrates 6 that is not the formation substrate.

  The light reflection variable unit 30 changes the degree of light reflectivity in the light reflection variable layer 3 by applying a voltage between the electrode 5p and the electrode 5q. The electrode 5p and the electrode 5q are electrically connected to the power source 50 through a wiring 53. By supplying power from the power supply 50, a voltage is applied to the light reflection variable unit 30. The power supply 50 of the light reflection variable unit 30 is constituted by an AC power supply 52. There are many materials whose light reflectivity changes due to an electric field, and the light reflectivity state at the time of voltage application cannot be maintained over time from the start of voltage application. In the AC power supply 52, a voltage can be alternately applied in both directions, and a voltage can be applied substantially continuously by changing the direction of the voltage. Therefore, stable light reflectivity can be obtained by the AC power supply 52. The AC waveform is preferably a rectangular wave. As a result, the amount of voltage to be applied is likely to be constant, so that the light reflectivity can be more stabilized. Of course, the alternating current may be a pulse. The intermediate reflection state can be formed by controlling the voltage application amount.

  As the material of the light reflection variable layer 3, a material whose molecular orientation is changed by electric field modulation can be used. Examples thereof include nematic liquid crystal, cholesteric liquid crystal, ferroelectric liquid crystal, and electrochromic. The cholesteric liquid crystal may be a nematic liquid crystal having a spiral structure. The cholesteric liquid crystal may be a chiral nematic liquid crystal. Cholesteric liquid crystals are called CLC. In cholesteric liquid crystals, the orientation direction of the molecular axes changes continuously in space, resulting in a macroscopic spiral structure. For this reason, it is possible to reflect light corresponding to the period of the spiral. By changing the liquid crystal state by an electric field, it is possible to control between light reflectivity and light transmissivity. In electrochromic, a color change phenomenon of a substance due to an electrochemical reversible reaction (electrolytic oxidation-reduction reaction) by applying a voltage can be used, and it is possible to control between light reflectivity and light transmissivity. As a material for the light reflection variable layer 3, cholesteric liquid crystal can be preferably used. In each drawing, a pattern imitating a spiral structure formed by liquid crystal is provided in the light reflection variable layer 3 so that the light reflection variable layer 3 can be easily understood.

The light reflection variable unit 30 is preferably in a light reflecting state when no voltage is applied and in a light transmitting state when a voltage is applied. In cholesteric liquid crystal, such control can be performed. This is because the alignment of liquid crystals can be made uniform by applying a voltage. In the cholesteric liquid crystal, the light reflection variable portion 30 which is thin and highly reflective can be formed. A state in which only specific light is reflected without applying a voltage is referred to as planar alignment, and a state in which light is passed through application of voltage is sometimes referred to as focal conic alignment. Of course, the light reflection variable unit 30 may be in a light transmission state when no voltage is applied and in a light reflection state when a voltage is applied.

  The light reflection variable layer 3 is a preferable embodiment in which the light reflection state when a voltage is applied is maintained. Thereby, a voltage is applied when it is desired to change the light reflection state, and when it is not, it is not necessary to apply a voltage, which increases power efficiency. The property that the light reflection state is maintained is called hysteresis. This property may be called memory property (memory property). Since the ferroelectric liquid crystal has a large hysteresis effect, it can exhibit a memory effect. Hysteresis can be exerted by applying a voltage higher than a predetermined voltage. The longer the time during which the light reflection state is maintained, the better. For example, it is preferably 1 hour or longer, more preferably 3 hours or longer, further preferably 6 hours or longer, more preferably 12 hours or longer, more preferably 24 hours or longer. More preferable.

  The planar light emitter 100 formed as described above includes a planar light emitting unit 10 formed of an organic EL element having optical transparency, a variable unit 20 that optically changes light from the organic electroluminescent element, 30 and a radio wave absorber 40 for absorbing radio waves. Such a planar light emitter 100 can create optically different states by having the planar light emitting part 10 and the variable parts 20 and 30. Further, the planar light emitter 100 can absorb radio waves by having the radio wave absorber 40. As a result, the planar light emitting body 100 having excellent optical characteristics and a function of absorbing radio waves can be obtained.

  Further, the planar light emitting body 100 is formed with the radio wave absorber 40 including carbon fibers 41 and a resin material 42. Therefore, the radio wave absorber 40 can absorb the radio wave with the carbon fiber 41 and hold it on the substrate 6 or the like with the resin material 42.

  The planar light emitter 100 is formed by providing the radio wave absorber 40 with a plurality of linear portions 43 in a lattice shape. Further, the linear portion 43 is formed including the carbon fiber 41 and the resin material 42. Accordingly, radio waves having a desired frequency can be absorbed according to the density and interval of the linear portions 43.

  Moreover, as for the planar light-emitting body 100, the carbon fiber 41 contains the carbon coil. Therefore, compared with a linear carbon fiber, the amount of carbon per unit amount of the radio wave absorber 40 can be increased, and the radio wave absorption performance of the radio wave absorber 40 can be increased.

  The planar light emitter 100 as described above is used as, for example, a lighting device. In the planar light emitter 100, for example, illumination changing in gradation can be obtained by optically varying the light from the planar light emitting unit 10 emitted by energization by the light scattering variable unit 20 or the light reflection variable unit 30. The planar light emitter 100 is used as a window, for example. A window that creates an optically different state may be defined as an active window. Windows that change gradation between non-transparent and transparent have high utility value. The window provided with the planar light emitter 100 can be used for both the inner window and the outer window. Moreover, the window provided with the planar light emitter 100 can also be used as an in-vehicle window. The in-vehicle window may be a window for vehicles such as an automatic vehicle, a train, a locomotive, and a train, an airplane, and a ship. For example, a window that can change between transparent and non-transparent is suitable for a high-class automobile.

  The planar light emitter 100 can be used as the building material 200. As shown in FIG. 7, the building material 200 is formed, for example, by fitting the planar light-emitting body 100 inside the frame-shaped holding unit 101. A feeder line 102 is connected to the outside of the holding unit 101 to energize the planar light emitting unit 10, the light scattering variable unit 20, the light reflection variable unit 30, and the like. A plug 103 that can be plugged into an outlet is provided at the tip of the power supply line 102. Such building materials 200 can be used for window materials, wall materials, partitions, signage, and the like. The signage may be a so-called lighting advertisement. The wall material may be for the outer wall or for the inner wall.

  As described above, the building material 200 of the present embodiment includes the planar light emitter 100 and the holding unit 101. For this reason, when the building material 200 is attached to another member such as a column or a wall member, it can be fixed at the location of the holding portion 101 and can be easily attached to the other member.

DESCRIPTION OF SYMBOLS 10 Planar light emission part 20 Variable part 30 Variable part 40 Radio wave absorption part 41 Carbon fiber 42 Resin material 43 Linear part 100 Planar light-emitting body 101 Holding part 200 Construction material

Claims (5)

  A planar light emitting unit including a light-transmitting organic electroluminescence element, a variable unit that optically changes light from the planar light emitting unit, and a radio wave absorbing unit that absorbs radio waves. Planar light emitter.   The planar light-emitting body according to claim 1, wherein the radio wave absorber is formed of carbon fiber and a resin material.   3. The surface according to claim 2, wherein the radio wave absorber is formed by providing a plurality of linear portions in a lattice shape, and the linear portions are formed by including the carbon fiber and the resin material. Luminous body.   The planar light-emitting body according to claim 2 or 3, wherein the carbon fiber contains a carbon coil. A building material comprising the planar light emitter according to any one of claims 1 to 4 and a holding unit that retains the planar light emitter.

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