JP5251225B2 - Organic electroluminescence light source device - Google Patents

Description

  The present invention relates to an organic electroluminescence (hereinafter sometimes abbreviated as “organic EL”) light source device.

  An organic EL device that provides an organic light emitting layer between multiple layers of electrodes to obtain light emission is used as a display device instead of a liquid crystal cell, as well as its high luminous efficiency, low voltage drive, light weight, low cost, etc. Utilization of the above features is also being considered for use as a planar light source such as a flat illumination and a backlight for a liquid crystal display device.

  When an organic EL element is used as a surface light source, it is a problem to extract useful light from the element with high efficiency. For example, although the light emitting layer itself of the organic EL element has high luminous efficiency, the light amount is reduced due to interference or the like in the layer before it emits light through the laminated structure constituting the element. Such light loss is required to be reduced as much as possible.

  As a method for increasing the light extraction efficiency, for example, in Patent Document 1, the luminance in the front direction (0 °) of the element is suppressed and the luminance at an angle of 50 to 70 ° is increased, thereby increasing the overall luminance. It is disclosed.

JP 2004-296423 A

However, the light source device is required to further improve the light extraction efficiency.

  In addition, in the light source device, the light intensity distribution may be required to be a predetermined distribution that maximizes the direction other than the front direction, and a light source device that emits light with such a light intensity distribution is required.

  Accordingly, an object of the present invention is to provide a light source device that has high light extraction efficiency and can have a luminous intensity distribution that maximizes the direction other than the front direction.

In order to solve the above-mentioned problems, the inventors of the present application have studied, and in the organic EL light source device, a pair of electrodes constituting the light emitting element are both transparent electrodes, and a reflective layer having a specific periodic structure is used. By providing, it discovered that the said subject could be solved and came to solve this invention.
Therefore, according to the present invention, the following [1] to [3] are provided.

[1] An organic electroluminescence light source device having a first transparent electrode layer, a light emitting layer, a second transparent electrode layer, and a reflective layer in this order, wherein the reflective layer includes a plurality of inclined surfaces. A cross-section of the periodic structural unit, the periodic structural unit being cut by a plane perpendicular to the main surface of the light emitting layer and passing through the highest position of the periodic structural unit. An organic electroluminescence light source device, wherein at least one of them has an asymmetric shape.
[2] A sealing adhesive layer is further provided between the second transparent electrode layer and the reflective layer, and the sealing adhesive layer is in direct contact with both the second transparent electrode and the reflective layer. The electroluminescence light source device as described above.
[3] In the cross section in which the periodic structural unit has a prismatic shape, the longitudinal direction of the prism is arranged parallel to the main surface of the light emitting layer, and the prism is cut by a plane perpendicular to the longitudinal direction. The organic electroluminescence light source device, wherein the cross section is asymmetric.

  The light source device of the present invention is useful as a light source for a backlight of a liquid crystal display device, an illumination device, etc., because the light extraction efficiency is high and the luminous intensity distribution can be a distribution in which a desired direction other than the front direction is maximized. is there.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is an elevational cross-sectional view showing the layer structure of the first embodiment of the organic EL light source device of the present invention. In the present application, unless otherwise specified, the light source device will be described in a state where the light emitting layer is placed horizontally and the light emitting surface of the device is placed upward. Therefore, unless otherwise specified, in the following description, the “horizontal plane” is a plane parallel to the main surface of the light emitting layer, the upper side of the light source device is the light exit surface side, and the lower side is the opposite side of the light exit surface.
In FIG. 1, the device 100 includes a substrate 101, a light emitting element 120 provided below the substrate 101, a sealing substrate 102 provided below the substrate 101, and an adhesive layer 132. And a reflection member 144 bonded to the lower side. The light emitting element 120 is sealed with the sealing layer 131, the sealing substrate 102, and the substrate 101. Accordingly, when the light source device 100 is used, the light emitting element 120 deteriorates due to contact with oxygen, moisture, or the like in the outside air. This can be prevented.

  The reflective member 144 includes a reflective substrate 140 having a periodic structure unit 141 on the upper surface, and a reflective layer 142 provided on the periodic structure unit 141 on the upper surface of the reflective substrate 140, and the reflective layer 142 seals the adhesive layer 132. Bonded to the lower side of the substrate 102.

(Substrate and sealing substrate)
As a material constituting the substrate 101 and the sealing substrate 102, a substrate that can be normally used as a substrate of an organic EL light-emitting element, such as a glass substrate, quartz glass, or a plastic substrate, can be employed. The material constituting the substrate 101 may be the same as or different from the material constituting the sealing substrate 102. The thickness of both the substrate and the sealing substrate can be 0.01 to 5 mm.

(Light emitting element)
The light-emitting layer 121 constituting the light-emitting element 120 is not particularly limited and can be appropriately selected from known ones. However, in order to suit the use as a light source, a single layer or a combination of a plurality of layers can be used. It can emit light including a predetermined peak wavelength described later.
The 1st transparent electrode layer 111 and the 2nd transparent electrode layer 112 which comprise the light emitting element 120 are located in the light emission surface side and reflective layer side of the light emitting layer 121, respectively. The material constituting these is not particularly limited, and a known material used as an electrode of an organic EL light-emitting element can be appropriately selected, and either one can be an anode and the other can be a cathode. Examples of the first transparent electrode 111 and the second transparent electrode 112 include ITO, IZO, and SnO ₂ .
In addition to the light emitting layer, the electrode may further include other layers such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and a gas barrier layer.

Specific layer configurations of the light-emitting element include anode / hole transport layer / light-emitting layer / cathode configuration, anode / hole transport layer / light-emitting layer / electron injection layer / cathode configuration, anode / hole injection layer / Composition of light emitting layer / cathode, anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode composition, anode / hole transport layer / light emitting layer / electron injection layer / equipotential Structure of surface forming layer / hole transport layer / light emitting layer / electron injection layer / cathode, anode / hole transport layer / light emitting layer / electron injection layer / charge generation layer / hole transport layer / light emitting layer / electron injection layer / Examples include the configuration of the cathode. The light-emitting element in the organic EL light source device of the present invention can have one or more light-emitting layers between the anode and the cathode, and as the light-emitting layer, a laminate of a plurality of layers having different emission colors, or A certain dye layer may have a mixed layer doped with different dyes. The material of each layer is not particularly limited. Examples of the light emitting material include polyparaphenylene vinylene, polyfluorene, and polyvinyl carbazole. Examples of the hole injection layer and the hole transport layer include phthalocyanine-based, arylamine-based, and polythiophene-based materials, and examples of the electron injection layer and the electron transport layer include aluminum complex and lithium fluoride. As the magnetic potential surface forming layer or the charge generation layer, ITO, IZO, the transparent electrode such as SnO _2, or Ag, a metal thin film such as Al and the like.

  The first transparent electrode layer 111, the light emitting layer 121, the second transparent electrode layer 112, and other arbitrary layers constituting the light emitting element can be provided by sequentially laminating them on the substrate 101. The thickness of each of these layers can be 10 to 1000 nm.

(Sealing layer)
The material constituting the sealing layer 131 has a function of adhering the second transparent electrode layer 112 and the sealing substrate 102, and the light emitting element 120 is deteriorated due to moisture, oxygen, etc. in the air during use of the device. Various types of resins that can prevent this can be used.

  As a material of the sealing layer, for example, a hot-melt adhesive functional resin that is welded by heating and cured by cooling can be used, and its glass transition temperature (Tg) is not particularly limited, but is usually −50 to 200 ° C. Preferably, a temperature of −10 to 100 ° C., more preferably 20 to 90 ° C., and particularly preferably 50 to 80 ° C. can be used. By setting the glass transition temperature in the preferred range, a light source device having sufficient heat resistance can be obtained, and the light emitting layer of the organic EL panel can be stuck without deteriorating.

  The adhesive functional resin is a conjugated diene polymer cyclized product obtained by cyclization reaction of a conjugated diene polymer, and the conjugated diene polymer cyclized product with respect to an unsaturated bond in the conjugated diene polymer. A conjugated diene polymer cyclized product having an existing unsaturated bond reduction rate (unsaturated bond reduction rate) of 30% or more can be used. Moreover, as said adhesive function resin, what contains the said conjugated diene polymer cyclization thing and alicyclic olefin resin can also be used.

  The conjugated diene polymer cyclized product is obtained by subjecting a conjugated diene polymer to a cyclization reaction in the presence of an acid catalyst. As the conjugated diene polymer, homopolymers and copolymers of conjugated diene monomers and copolymers of conjugated diene monomers and monomers copolymerizable therewith can be used.

  The conjugated diene monomer is not particularly limited, and specific examples thereof include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1, Examples include 3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene. These monomers may be used alone or in combination of two or more.

  Specific examples of conjugated diene polymers include homopolymers or copolymers of conjugated dienes such as natural rubber, polyisoprene, and butadiene-isoprene copolymers; styrene-butadiene copolymers, styrene-isoprene copolymers, isoprene. -Aromatic vinyl-conjugated diene block copolymer such as isobutylene copolymer, ethylene-propylene-diene copolymer rubber, styrene-isoprene block copolymer, etc. And a copolymer with the body. Among these, natural rubber, polyisoprene, and styrene-isoprene block copolymer are preferable, and polyisoprene and styrene-isoprene block copolymer are more preferable.

  As the conjugated diene polymer cyclized product, a modified conjugated diene polymer cyclized product modified with a polar group is preferably used. The modified conjugated diene polymer cyclized product develops adhesion to the adherend of the adhesive functional resin containing it, and improves the dispersibility of the fine particles when the adhesive functional resin contains fine particles. There is an effect to make. One kind of the modified conjugated diene polymer cyclized product containing a polar group may be contained in the adhesive functional resin, and plural kinds of different polar groups are contained in the adhesive functional resin. Also good. Further, a conjugated diene polymer cyclized product having two or more kinds of functional groups may be used.

  The polar group is not particularly limited, and examples thereof include an acid anhydride group, carboxyl group, hydroxyl group, thiol group, ester group, epoxy group, amino group, amide group, cyano group, silyl group, and halogen. Can be mentioned.

  Examples of the acid anhydride group or carboxyl group include maleic anhydride, itaconic anhydride, aconitic anhydride, norbornene dicarboxylic acid anhydride, vinyl carboxylic acid compounds such as acrylic acid, methacrylic acid, and maleic acid. Examples include a group having a structure added to a cyclized product of a polymer, and among them, a group having a structure in which maleic anhydride is added to a cyclized product of a conjugated diene polymer is preferable in terms of reactivity and economy.

  Amide group is introduced by grafting conjugated diene polymer cyclized product using unsaturated compound containing amide group; introducing functional group using unsaturated compound containing functional group Then, it can be introduced by a method of reacting the introduced functional group with a compound having an amide group. Examples of the unsaturated compound containing an amide group include acrylamide, N-isopropylacrylamide, N, N-dimethylacrylamide, and N-benzylacrylamide.

  Examples of the hydroxyl group include hydroxyalkyl esters of unsaturated acids such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, N-methylol (meth) acrylamide, and N- (2 -Unsaturated acid amides having hydroxyl groups such as hydroxyethyl) (meth) acrylamide, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and poly (ethylene glycol-propylene glycol) mono (meth) acrylate Groups of structures in which polyalkylene glycol monoesters of unsaturated acids such as, and polyhydric alcohol monoesters of unsaturated acids such as glycerol mono (meth) acrylate are added to the conjugated diene polymer cyclized product, This Among al, hydroxyalkyl esters of unsaturated acids are preferred, particularly 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate is a group of the structure obtained by adding the conjugated diene polymer cyclized product preferred.

  Examples of vinyl compounds containing other polar groups include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl ( And (meth) acrylate, (meth) acrylamide, and (meth) acrylonitrile.

  The content of the polar group in the modified conjugated diene polymer cyclized product, particularly the polar group-containing conjugated diene polymer cyclized product is not particularly limited, but is usually 0.1 to 15 mol%, preferably 0.5 to 10 mol. %, More preferably in the range of 1 to 7 mol%. If the content is too small or too large, the oxygen absorption function tends to be inferior. In addition, content of a polar group makes 1 mol the molecular weight equivalent amount of the polar group couple | bonded with the molecule | numerator of a modified conjugated diene polymer cyclization thing.

  As a method for producing a modified conjugated diene polymer cyclized product, (1) a method in which a conjugated diene polymer cyclized product obtained by the above-described method is subjected to an addition reaction with a polar group-containing vinyl compound, and (2) a polar group is contained. A method of obtaining a conjugated diene polymer by cyclization reaction by the above-mentioned method, (3) An addition reaction of a vinyl compound containing a polar group to a conjugated diene polymer not containing a polar group, followed by a cyclization reaction. And (4) a method of further adding a polar group-containing vinyl compound to the product obtained by the method (2) or (3). Especially, the point of said (1) is preferable from the point which can adjust an unsaturated bond decreasing rate more easily.

  The polar group-containing vinyl compound is not particularly limited as long as it is a compound that can introduce a polar group into a conjugated diene polymer cyclized product. For example, an acid anhydride group, a carboxyl group, a hydroxyl group, a thiol group, Preferred examples include vinyl compounds having polar groups such as ester groups, epoxy groups, amino groups, amide groups, cyano groups, silyl groups, and halogens.

  Examples of the vinyl compound having an acid anhydride group or a carboxyl group include maleic anhydride, itaconic anhydride, aconitic anhydride, norbornene dicarboxylic acid anhydride, acrylic acid, methacrylic acid, and maleic acid. Maleic anhydride can be preferably used in terms of reactivity and economy. As a vinyl compound containing a hydroxyl group, for example, hydroxyalkyl esters of unsaturated acids are preferable, and 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are particularly preferable vinyl compounds.

  The method for adding a polar group-containing vinyl compound to a conjugated diene polymer cyclized product and introducing a polar group derived from the polar group-containing vinyl compound is not particularly limited, but is generally an ene addition reaction or a graft polymerization reaction. What is necessary is just to follow the well-known reaction called. This addition reaction is carried out by contacting the conjugated diene polymer cyclized product with the polar group-containing vinyl compound in the presence of a radical generator, if necessary. Examples of the radical generator include peroxides such as di-tert-butyl peroxide, dicumyl peroxide, and benzoyl peroxide, and azonitriles such as azobisisobutyronitrile.

  The conjugated diene polymer cyclized product has at least two kinds of unsaturated bonds, ie, a linear unsaturated bond inherent to the conjugated diene and a cyclic unsaturated bond of the cyclized portion, except for a 100% cyclized product. ing. In the conjugated diene polymer cyclized product, it is considered that the cyclic unsaturated bond portion greatly contributes to oxygen absorption, and the linear unsaturated bond portion hardly contributes to oxygen absorption. Therefore, a conjugated diene polymer cyclized product having a reduction rate of unsaturated bonds (unsaturated bond reduction rate) in the conjugated diene polymer cyclized product with respect to unsaturated bonds in the conjugated diene polymer of 30% or more is It is essential as a material for the oxygen absorbing member in the light emitting device of the invention. The unsaturated bond reduction rate of the conjugated diene polymer cyclized product is preferably 40 to 75%, more preferably 55 to 70%. If the unsaturated bond reduction rate is too low, oxygen absorption tends to deteriorate. The conjugated diene polymer cyclized product prevents the conjugated diene polymer cyclized product from becoming brittle by making the unsaturated bond reduction rate less than or equal to the upper limit of the above preferred range, facilitates production, and causes gelation during production. Progression is suppressed, transparency is improved, and it can be used for many purposes. Further, if the unsaturated bond reduction rate exceeds 50%, adhesiveness is exhibited, and this property can be utilized.

Here, the unsaturated bond reduction rate is an index representing the degree to which the unsaturated bond is reduced by the cyclization reaction in the conjugated diene monomer unit site in the conjugated diene polymer, and is a numerical value obtained as follows. is there. That is, by proton NMR ( ¹ H-NMR) analysis, in the conjugated diene monomer unit portion in the conjugated diene polymer, the ratio of the peak area of protons directly bonded to double bonds to the peak area of all protons is Calculate the reduction rate before and after the chemical reaction.

Now, in the conjugated diene polymer unit site in the conjugated diene polymer, the total proton peak area before the cyclization reaction is SBT, the peak area of the proton directly bonded to the double bond is SBU, and the total proton after the cyclization reaction When the peak area is SAT and the peak area of the proton peak directly bonded to the double bond is SAU, the peak area ratio (SB) of the proton directly bonded to the double bond before the cyclization reaction is SB = SBU / SBT, The peak area ratio (SA) of the proton directly bonded to the double bond after the cyclization reaction is expressed as SA = SAU / SAT. Therefore, the unsaturated bond reduction rate is
Unsaturated bond reduction rate (%) = 100 × (SB−SA) / SB
As required.

  The oxygen absorption amount of the conjugated diene polymer cyclized product used in the present invention is 5 ml / g or more, preferably 10 ml / g or more, more preferably 50 ml / g or more. The oxygen absorption amount is the amount of oxygen absorbed by 1 g of the conjugated diene polymer cyclized product when the conjugated diene polymer cyclized product is sufficiently absorbed as a powder or thin film to reach a saturated state at 23 ° C. If the amount of oxygen absorbed is small, a large amount of conjugated diene polymer cyclized product is required to stably absorb oxygen for a long period of time. The amount of oxygen absorbed is mainly correlated with the unsaturated bond reduction rate in the conjugated diene polymer cyclized product.

In the present invention, the conjugated diene polymer cyclized product used has an oxygen absorption rate from the surface of 1.0 ml / m ² · day or more, preferably 5.0 ml / m ² · day or more, more preferably 10 ml / m ^2. -More than a day. Even if the conjugated diene polymer cyclized product has a large oxygen absorption ability, if the oxygen absorption rate is too slow, oxygen entering from the outside may not be sufficiently absorbed and transmitted. Further, when used as a sealing layer of a light-emitting element, oxygen that has existed or entered in the sealing space for some reason must be quickly absorbed and removed by the conjugated diene polymer cyclized product layer. From this point of view, those having the above-described oxygen absorption rate are desirable.

  The content of the conjugated diene polymer cyclized product in the adhesive functional resin is usually 5 to 90% by weight, preferably 15 to 70% by weight. When the content of the conjugated diene polymer cyclized product is lower than the lower limit value, there may be a disadvantage that the oxygen absorption capacity and the adhesion force at room temperature (25 ° C.) are lowered. There is a possibility that the strength is lowered.

  The alicyclic olefin resin is an amorphous resin having an alicyclic structure such as a cycloalkane structure or a cycloalkene structure in the main chain and / or side chain. From the viewpoint of mechanical strength and heat resistance, a polymer containing an alicyclic structure in the main chain is preferred. Examples of the alicyclic structure include monocycles and polycycles (condensed polycycles, bridged rings, etc.). Among the alicyclic structures, a cycloalkane structure is preferable. The number of carbon atoms constituting one unit of the alicyclic structure is not particularly limited, but is usually 4-30, preferably 5-20, more preferably 5-15. Various properties such as mechanical strength, heat resistance, and moldability are highly balanced and suitable. Specific examples of the alicyclic olefin resin include (1) norbornene polymer, (2) monocyclic olefin polymer, (3) cyclic conjugated diene polymer, and (4) vinyl alicyclic hydrocarbon. Examples thereof include a polymer and a mixture thereof. Among these, a norbornene polymer and a vinyl alicyclic hydrocarbon polymer are preferable from the viewpoints of optical properties, heat resistance, and mechanical strength. Further, when an alicyclic olefin resin having a polar group is used as the alicyclic olefin resin, the affinity with an inorganic substance can be improved without impairing the light transmittance.

  The formation method of the sealing layer 131 is not particularly limited, but a layer of an adhesive functional resin such as those described above is provided on the sealing substrate 102 and / or the second transparent electrode 112, and the adhesive functional resin is formed. The sealing substrate 102 and the second transparent electrode 112 can be pasted through layers, and further heated and welded as necessary. The thickness of the sealing layer can be 1 to 1000 μm.

  Usually, such an adhesive functional resin itself does not have the ability to shield moisture and oxygen in the air, and the shielding from the outside air itself can be performed by the substrate 101 and the sealing substrate 102, but the resin is sealed therein. By using a material capable of absorbing oxygen and moisture as the material of the sealing layer 131, the light emitting layer 120 can be more effectively prevented from being deteriorated, and a light source device having a longer life can be obtained.

(Reflective layer)
In the present invention, the reflective layer has a periodic structure composed of repeating periodic structural units including a plurality of inclined surfaces. As an example, FIG. 2 shows a periodic structure in the embodiment shown in FIG. As shown in FIG. 2, the periodic structure 141 is provided on the upper surface of the reflective substrate 140, and the reflective layer 142 is formed on the reflective substrate 140 with a uniform film thickness thereon, thereby forming a set of inclined surfaces 142S1 and 142S2. A reflective layer having a periodic structure composed of repeating periodic structural units is obtained (a vertical surface such as the inclined surface 142S2 is not excluded from the category of “inclined surface” in the present application). Here, as a material of the reflective substrate 140, glass, plastic, a metal plate, or the like can be used. As a material of the reflective layer 142, a metal film such as Ag, Au, or Al can be used. By setting it as such a structure, the reflection layer which has a desired periodic structure can be obtained easily.

(Reflective layer periodic structure)
In the present invention, the term “periodic structure” means that a structural unit repeatedly exists from one position in the horizontal plane to another certain position, and the term “periodic structural unit” refers to each of the structural units. In the present invention, the periodic structural unit in the reflective layer satisfies the following predetermined requirements. That is, the periodic structural unit is a plane perpendicular to the main surface of the light emitting layer and passing through the highest position of the periodic structural unit (hereinafter referred to as plane A). At least one of the cross sections (hereinafter referred to as cross section B) has an asymmetric shape.

  The main surface of the light emitting layer is the front surface or the back surface of the light emitting layer, and is usually a surface of the substrate parallel to the surface on which the light emitting element is provided. In the embodiment shown in FIG. 1, the light exit surface 100A of the substrate 101, the surface 100B on which the light emitting element on the back side is provided, the main surface of each layer constituting the light emitting element 120, and the front and back main surfaces of the sealing substrate 102 are any. Also, the plane perpendicular to the main surface of the light emitting layer is a plane perpendicular to all these planes.

The highest position of the periodic structural unit means the highest position in a state where the light emitting surface of the light source device is placed horizontally upward, and corresponds to the highest position in the coordinate axis Z direction in the perspective view of FIG. Each corresponds to the ridgeline 142R of the periodic structure unit 141 having a triangular prism shape.
Since an arbitrary plane parallel to the Z-axis in FIG. 2 can be the plane A, the section B obtained by cutting the periodic structural unit on the plane can be considered innumerably, but at least one of them has an asymmetric shape. As a requirement.

  Specifically, for example, the periodic structural unit has a prismatic shape as in the example shown in FIG. 2, and the longitudinal direction (the coordinate axis Y direction in FIG. 2) is the main surface of the light emitting layer (the coordinate axis X in FIG. 2). And a plane parallel to Y), a section obtained by cutting the prism at a plane perpendicular to the longitudinal direction of the prism (plane parallel to the coordinate axes X and Z in FIG. 2) is defined as section B. This preferably has an asymmetric shape.

  In the present invention, the cross section B is symmetrical means a shape that is symmetric with respect to any of the lines (in the coordinate axis Z direction in FIG. 2) perpendicular to the main surface of the light emitting layer, and asymmetric means light emission. It means that it is not symmetrical about any of the lines perpendicular to the main surface of the layer. For example, FIG. 11 is a cross-sectional view of the periodic structural unit 141 shown in FIG. 2 cut along a plane parallel to the coordinate axes X and Z. Each cross-section 141CS is a triangular figure and satisfies the requirements of the present invention because it is not symmetric with respect to any of the lines passing through the base 141BS corresponding to the width of the periodic structural unit and parallel to the Z-axis direction.

  Each of the periodic structural units 141 shown in FIGS. 2 and 11 has an inclined surface 141S1 having an apex angle 141Q1 of 45 ° and inclined at 45 ° with respect to the main surface, and an inclined surface 141S2 perpendicular to the main surface. However, the shape of the periodic structure unit cross section is not limited to this, and for example, the periodic structure unit cross section 1141CS formed of surfaces 1141S1 and 1141S2 inclined at different angles with respect to the main surface as shown in FIG. Various shapes such as a rounded periodic structural unit cross section 1142CS as shown in FIG. 13 can be taken.

(Adhesive layer)
As a material constituting the adhesive layer 132, the same material as that of the sealing layer 131 can be used, but not limited thereto, and various known adhesives used for bonding optical members can be used. Specifically, for example, Aron Alpha (registered trademark) manufactured by Toagosei Co., Ltd. can be used.

  The method for forming the adhesive layer 132 is not particularly limited, and a composition for forming an adhesive layer is applied to the surface of the sealing substrate 102 and / or the reflective layer 142, and the sealing substrate 102 and the reflective layer 142 are applied to the composition. It can be formed by pasting through a coating layer, and photocuring, heating, drying, etc., if necessary. The thickness of the adhesive layer can be 1-1000 μm.

  In the organic EL light source device of this embodiment, the light emitting layer 121 emits light when a voltage is applied to the first transparent electrode layer 111 and the second transparent electrode layer 112. A part of the generated light passes through the first transparent electrode layer 111, passes through the substrate 101, and exits from the light exit surface 100A. Other portions of the generated light can take various paths. For example, after passing through the second transparent electrode layer 112, the light passes through the sealing layer 131, the sealing substrate 102, and the adhesive layer 132, and the reflective layer. 142, the light is reflected by the reflective layer 142, follows an upward path, and exits from the light exit surface 100A. Further, in addition to the interface between the reflective layer 142 and the adhesive layer 132, reflection can also occur at the interface between the layers from the substrate 101 to the adhesive layer 132. The light reflected downward at the interface between the substrate 101 and the adhesive layer 132 undergoes a change in the traveling direction by the inclined surface of the reflective layer 142 and is emitted. Thus, the interference of light can be suppressed and the light extraction efficiency can be increased by the effect that the reflection layer 142 is non-planar and the distance between the light emitting layer 121 and the reflection layer is not constant and the reflection and diffusion are effected.

  Further, since the periodic structural unit is asymmetric in the cross section B, when the luminous intensity distribution of light emitted from various angles parallel to the cross section B from the light exit surface is seen, the maximum luminous intensity is in a direction other than the front direction. Since the light is emitted in the form of a luminous intensity distribution, the apparatus of the present invention can be advantageously used as a surface light source such as a signboard or a display device that is mainly observed from a direction other than the front.

(Second Embodiment)
FIG. 4 is an elevational cross-sectional view showing the layer structure of the second embodiment of the organic EL light source device of the present invention. In FIG. 4, the apparatus 400 is different from the first embodiment in that a diffusion plate 460 is further provided on the light exit surface side from the substrate 101. In the example shown in FIG. 4, the substrate 101 and the diffusion plate 460 are separated from each other or the diffusion plate 460 is placed on the base 101 so that an air layer 451 exists between them. A periodic structure composed of periodic structure units 461 is provided on the light exit surface side of the diffusion plate 460.

  In the embodiment shown in FIG. 4, the diffusion plate 461 has a periodic structure composed of periodic structure units 461 on the light exit surface side. The periodic structure unit 461 has a prismatic shape, the longitudinal direction of which is arranged in parallel to the longitudinal direction of the periodic structure unit 141 of the reflective layer, and a cross section cut by a plane perpendicular to the longitudinal direction is a triangle having an apex angle 461Q1. And an inclined surface 461S1 inclined at an angle 461Q2 and an inclined surface 461S2 inclined at an angle 461Q3 with respect to the horizontal plane. By further including a diffusion plate having such a periodic structure, the light condensing degree can be increased.

(Third embodiment)
FIG. 6 is an elevational sectional view showing a layer structure of the third embodiment of the organic EL light source device of the present invention. The present embodiment is a further modification of the second embodiment. In FIG. 6, the apparatus 600 has a structure in which the periodic structure unit 661 of the light exit surface is similar to the periodic structure 141, and an adhesive layer 652 is provided instead of the air layer 451 to bond the substrate 101 and the diffusion plate 660. The second embodiment is different from the second embodiment in that it is the mode described above. In this case, examples of the material for the adhesive layer include the same materials as those described above as the material for the adhesive layer 132. By having the diffusion plate in such a manner, the light extraction efficiency can be increased and the luminous intensity distribution can be made desired.

(Fourth embodiment)
FIG. 7 is an elevational cross-sectional view showing the layer configuration of the fourth embodiment of the organic EL light source device of the present invention. The present embodiment is a further modification of the second embodiment. In FIG. 7, the apparatus 700 is different from the second embodiment in that the light exit surface side of the diffuser plate 760 of the light exit surface is a flat surface and a periodic structure composed of the periodic structure units 761 is provided on the light entrance surface side. . As described above, even when the periodic structure is provided on the light incident surface side of the diffusion plate, the light extraction efficiency can be increased and the luminous intensity distribution can be made desired.

(Fifth embodiment)
FIG. 8 is an elevational sectional view showing the layer structure of the fifth embodiment of the organic EL light source device of the present invention. The present embodiment is a further modification of the third embodiment shown in FIG. In FIG. 8, the apparatus 800 is different from the third embodiment in that a film 860 having a scattering function is provided on the light exit surface side of the substrate 101 via an adhesive layer 652. As described above, even when the film having the scattering function is provided on the light exit surface side of the substrate, the light extraction efficiency can be increased and the luminous intensity distribution can be made desired.

  As a film having such a scattering function, a film obtained by molding a resin composition in which particles as fillers are dispersed in a resin into a film shape can be used.

  Examples of the resin include an epoxy resin, a silicone resin, an acrylic resin, polyethylene, a propylene-ethylene copolymer, polystyrene, and a copolymer of an aromatic vinyl monomer and a (meth) acrylic acid alkyl ester having a lower alkyl group. , Polyethylene terephthalate, terephthalic acid-ethylene glycol-cyclohexanedimethanol copolymer, polycarbonate, resin having an alicyclic structure, and the like can be used.

The material of the filler is not particularly limited, and inorganic and organic fillers can be appropriately selected and used.
Inorganic fillers include glass, silicon oxide, aluminum hydroxide, aluminum oxide, titanium oxide, zinc oxide, barium sulfate, magnesium silicate, etc .; organic fillers include fluororesin, polystyrene resin, acrylic resin, polycarbonate resin, Examples thereof include silicone resin, polyethylene resin, ethylene-vinyl acetate copolymer, acrylonitrile, polyurethane, polyvinyl chloride, polyacrylonitrile, polyamide, polysiloxane resin, melamine resin, benzoguanamine resin, or a cross-linked product thereof.

  The shape of the filler is not particularly limited, and examples thereof include a spherical shape, an ellipsoidal shape, a cubic shape, a needle shape, a rod shape, a spindle shape, a plate shape, a scale shape, and a fiber shape. Spherical or nearly ellipsoidal shape is preferable in that it can be achieved.

  The size of the filler is preferably 0.2 μm to 50 μm in diameter, more preferably 0.5 μm to 10 μm. In addition, when the diameter here is not a perfect sphere, the diameter of the sphere of the same volume is substituted. In the case of a filler having a significantly different size in one direction such as a needle shape, a diameter of a circle having the same area as the cross-sectional area of the cross section perpendicular to the direction is substituted.

  The refractive index of the filler is preferably different from the refractive index of the resin, and the refractive index difference is more preferably 0.05 or more.

  The filler may be a single material, size, refractive index or other properties, or a mixture of two or more fillers. Moreover, you may use what consists of 2 or more types of raw materials as a filler.

  The content of the filler in the diffusion layer composed of the resin and filler is preferably 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the resin.

  The ratio between the average particle diameter d of the filler contained in the film having a diffusion function and the thickness l of the film is preferably 0.05 ≦ d / l ≦ 0.6, particularly preferably 0.07 ≦ d / l ≦. 0.3. If it is less than 0.05, the particle size of the filler is too small or the layer thickness is too thick, so if the former, the necessary scattering characteristics may not be obtained, but the latter does not require an unnecessary retardation. If it exceeds 0.6, the adhesive force between the film and other layers may be insufficient, and the film may be peeled off. The thickness of the film can be 0.02 to 3.0 mm.

(Sixth embodiment)
FIG. 9 is an elevational sectional view showing the layer structure of the sixth embodiment of the organic EL light source device of the present invention. This embodiment is a modification of the first embodiment shown in FIG. In FIG. 9, the device 900 includes a sealing adhesive layer 932 instead of the sealing layer 131, the sealing substrate 102, and the adhesive layer 132 below the second transparent electrode layer 112. It is different from the embodiment. That is, in the present embodiment, the sealing adhesive layer 932 is in direct contact with both the second transparent electrode 112 and the reflective layer 142. With such a configuration, the reflective layer 142 seals the light emitting element 120 (the first transparent electrode layer 111, the light emitting layer 121, and the second transparent electrode layer 112) instead of the sealing substrate 102. Deterioration can be prevented with a simple layer structure, and a thin, inexpensive and long-life light source device can be obtained.

(Seventh embodiment)
FIG. 10 is an elevational sectional view showing the layer structure of the seventh embodiment of the organic EL light source device of the present invention. The present embodiment is a further modification of the sixth embodiment shown in FIG. In FIG. 10, the apparatus 1000 is different from the sixth embodiment in that it includes a diffusion plate 760 having a periodic structural unit 761 similar to that in the fourth embodiment shown in FIG. By further including the diffusion plate as described above, it is possible to prevent deterioration with a simple layer configuration as in the case of the sixth embodiment, and it is thin, inexpensive and has a long life, and enhances the light extraction efficiency and the luminous intensity distribution. A light source device that can be set as desired can be obtained.

  As a further modification of the seventh embodiment, the diffusion plate 460 of the second embodiment shown in FIG. 4 is provided instead of the diffusion plate 760, or the adhesive layer 652 and the diffusion plate 660 of the third embodiment shown in FIG. Or the adhesive layer 652 of the fifth embodiment shown in FIG. 8 and the film 860 having a scattering function can be provided. Also with these configurations, it is possible to obtain a light source device that is thin, inexpensive, has a long life, can enhance light extraction efficiency, and can have a desired light intensity distribution.

(Use)
The use of the organic EL light source device of the present invention is not particularly limited, but it can be used as a light source for a backlight of a liquid crystal display device, a lighting device, etc. by taking advantage of high light extraction efficiency and high degree of freedom in controlling the orientation distribution. be able to.

  The light source device of the present invention includes not only those specifically described above but also those belonging to the scope of the claims of the present application and their equivalents. For example, the light source device of the present invention includes a first transparent electrode layer, a light emitting layer, a second transparent electrode layer, and a reflective layer as essential components, and the light emitted from the first transparent electrode is between these layers. In addition to the diffusing plate, sealing layer, reflecting substrate, etc. exemplified above as optional components, any layer on the surface side and on the back side (opposite side of the light emitting surface) from the reflective layer Can have. In addition, the upper and lower substrates, the sealing substrate, the sealing layer, and the like are exemplified as the one that seals the light emitting element, but in addition, a sealing member that seals the edge of the light emitting element is further provided. be able to. Further, other optional components necessary for configuring the light source device, such as energization means for energizing the electrodes, can be provided.

  Hereinafter, the present invention will be described in more detail based on examples. In addition, this invention is not limited to the following Example.

<Production Example 1: Preparation of adhesive for sealing layer>
After 300 parts by weight of polyisoprene was completely dissolved in 700 parts by weight of toluene, 2.4 parts by weight of p-toluenesulfonic acid was added and a cyclization reaction was performed to obtain a polymer cyclized product solution.
An addition reaction was performed by adding 2.5 parts by weight of maleic anhydride to 100 parts by weight of the polymer cyclized product in the obtained solution.
A part of toluene in the solution is distilled off, an antioxidant is added, and then vacuum drying is performed to remove toluene and unreacted maleic anhydride, thereby modifying a modified conjugated diene polymer cyclized adhesive. Got.

<Example 1>
An organic EL light source device having the configuration of the first embodiment of the present invention shown in FIG. 1 was manufactured.

(1-1: Preparation of light-emitting element)
An organic EL light-emitting element including the first transparent electrode 111, the organic light-emitting layer 121, and the second transparent electrode 112 was provided on one surface of a glass substrate 101 having a thickness of 1.1 mm.

(1-2: Preparation of laminated body in which light-emitting element is sealed)
The adhesive for sealing layer obtained in Production Example 1 was applied on one surface of a glass sealing substrate 102 having a thickness of 0.7 mm, and this was applied to the light emitting device obtained in (1-1). 2 is attached to the surface of the transparent electrode, and a means for energizing the electrode layer is provided at the periphery of the element and sealed with a peripheral sealing member (not shown in FIG. 1), and a sealing layer 131 having a thickness of 15 μm is formed. Thus, a laminate including the substrate 101, the first transparent electrode 111, the organic light emitting layer 121, the second transparent electrode 112, the sealing layer 131, and the sealing substrate 102 was obtained.

(1-3: reflective substrate)
A reflective substrate 140 was formed from a pellet of a resin having an alicyclic structure (Nippon Zeon Co., Ltd., ZEONOR) using an injection molding machine. The obtained reflective substrate has a thickness of 0.7 mm, and on one surface thereof, a number of triangular prism shapes that are periodic structural units as shown in FIGS. And had a surface shape composed of rows arranged in parallel to each other without a gap. The width of each triangular prism (width 141BS in FIG. 11) was 10 μm.

(1-4: reflective layer having a periodic structure)
A metal reflective layer is formed by vapor-depositing Al on the surface of the reflective substrate 140 obtained in (1-3) on which the rows are formed, and includes a reflective substrate 140 and a reflective layer 142 having a periodic structure. A laminate was obtained.

(1-5: Manufacture of light source device)
The sealing adhesive obtained in Production Example 1 is applied to the reflective layer 142 side surface of the laminate obtained in (1-4), and this is sealed in the laminate obtained in (1-2). Adhering to the stationary substrate 102 side, an adhesive layer 132 having a thickness of 15 μm (distance from the highest part of the periodic structure to the sealing substrate 102) is formed, whereby the substrate 101, the first transparent electrode 111, and the organic light emission An organic EL light source device having the layer 121, the second transparent electrode 112, the sealing layer 131, the sealing substrate 102, the adhesive layer 132, the reflective layer 142, and the reflective substrate 140 was obtained.

(1-6: Evaluation)
The obtained organic EL light source device was energized to emit light, and the luminous intensity distribution from the light exit surface 100A was measured using EZ-contrast manufactured by ELDIM. The normal direction of the light exit surface 110A was set to 0 °, the observation direction was tilted along the repeating direction of the periodic structure (X-axis direction in FIG. 2), and the relationship between the observation angle and the luminous intensity was obtained. The results are shown in FIG. As shown in FIG. 3, the highest luminous intensity was obtained when the observation angle was around + 40 °. Further, when the total luminous flux of this light source device was obtained, it increased by 20%.

<Example 2>
An organic EL light source device having the configuration of the second embodiment of the present invention shown in FIG. 4 was manufactured.

(2-1: Preparation of diffusion plate)
A diffusion plate 460 was formed from pellets of a resin having an alicyclic structure (Nippon Zeon Co., Ltd., ZEONOR) using an injection molding machine. The obtained diffuser plate has a thickness of 0.7 mm, and on one surface thereof, a large number of triangular prismatic linear prisms, which are periodic structural units as shown in FIG. It had a surface shape consisting of prism rows provided parallel to each other without gaps. The width of each linear prism was 50 μm, the apex angle 461Q1 was 90 °, the inclination angle 461Q2 of the inclined surface 461S1 was 25 °, and the inclination angle 461Q3 of the inclined surface 461S2 was 65 °.

(2-2: Manufacture of light source device)
On the light emission surface of the organic EL light source device obtained in the step (1-5) of Example 1, the diffusion plate obtained in (2-1) is placed through the air layer 451 using an appropriate support means. And the organic EL light source device concerning a present Example was obtained.

(2-3: Evaluation)
The obtained organic EL light source device was energized to emit light, and evaluated in the same manner as in Example 1 (1-6). The measurement result of the relationship between the observation angle and the luminous intensity is shown in FIG. As shown in FIG. 5, the highest luminous intensity was obtained when the observation angle was around + 20 °.

1 is an elevational sectional view schematically showing an organic EL light source device according to an embodiment of the present invention. FIG. 2 is a perspective view showing more specific shapes of a reflective substrate 140 and a reflective layer 142 in the organic EL light source device shown in FIG. 1. It is a graph which shows the relationship between the observation angle and luminous intensity of the organic electroluminescent light source device shown in FIG. It is an elevational sectional view schematically showing an organic EL light source device according to another embodiment of the present invention. It is a graph which shows the relationship between the observation angle and luminous intensity of the organic electroluminescent light source device shown in FIG. It is an elevational sectional view schematically showing an organic EL light source device according to still another embodiment of the present invention. It is an elevational sectional view schematically showing an organic EL light source device according to still another embodiment of the present invention. It is an elevational sectional view schematically showing an organic EL light source device according to still another embodiment of the present invention. It is an elevational sectional view schematically showing an organic EL light source device according to still another embodiment of the present invention. It is an elevational sectional view schematically showing an organic EL light source device according to still another embodiment of the present invention. FIG. 3 is a partial elevation sectional view showing a section of the periodic structure shown in FIG. 2. It is a partial elevation sectional view showing another example of a periodic structure. It is a partial elevation sectional view showing another example of a periodic structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Substrate 120 Light emitting element 111 1st transparent electrode layer 112 2nd transparent electrode layer 121 Light emitting layer 131 Sealing layer 102 Sealing substrate 132 Adhesive layer 140 Reflective substrate 141 Periodic structural unit 142 Reflective layer 460, 660, 760, 860 Diffusion plate

Claims (4)

An organic electroluminescence light source device having a first transparent electrode layer, a light emitting layer, a second transparent electrode layer, and a reflective layer in this order,
The reflective layer has a periodic structure composed of repeating periodic structural units including a plurality of inclined surfaces;
At least one of the cross-sections of the periodic structural unit, which is a plane perpendicular to the main surface of the light emitting layer and cuts the periodic structural unit at a plane passing through the highest position of the periodic structural unit, has an asymmetric shape. Ri, there are major surface parallel to the light exit surface of the light-emitting layer, the organic electroluminescent light source device according to claim Rukoto to have a maximum luminous intensity in the direction other than the front direction of the main surface of the light emitting surface.   A sealing adhesive layer is further provided between the second transparent electrode layer and the reflective layer, and the sealing adhesive layer is in direct contact with both the second transparent electrode and the reflective layer. The organic electroluminescence light source device according to claim 1. The periodic structural unit has a prismatic shape;
The longitudinal direction of the prism is arranged in parallel with the light emitting layer main surface,
The organic electroluminescence light source device according to claim 1, wherein the cross section is asymmetric in a cross section obtained by cutting the prism in a plane perpendicular to the longitudinal direction. A diffusion plate and a substrate;
The diffusion plate, the substrate, the first transparent electrode layer, the light emitting layer, the second transparent electrode layer, and the reflective layer in this order,
The organic electroluminescence light source device according to claim 1, wherein an air layer or an adhesive layer is present between the diffusion plate and the substrate.

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