JP6416307B2 - Light emitting element - Google Patents

Description

  The present invention relates to a light emitting element.

  As one of the light emitting elements, there is a light emitting element having an organic light emitting layer, that is, an organic EL (Electro Luminescence) element. Organic EL elements include a flexible type, that is, a type that has flexibility and can be bent (curved) (Patent Documents 1 to 5). Among such flexible organic EL elements, there is a type in which the base material includes a glass substrate (Patent Documents 1 and 2). The glass substrate can suppress moisture and oxygen permeation as compared with the resin layer.

  Patent Document 3 describes that the stress generated in the inorganic moisture-proof layer is reduced by disposing the inorganic moisture-proof layer at a substantially central portion in the thickness direction of the organic EL element. Similarly, in Patent Document 4, a gas barrier layer made of silicon oxide or silicon oxynitride is arranged in the vicinity of a position that becomes a neutral surface when the organic EL element is warped, thereby reducing the generation of stress in the gas barrier layer. There is a statement to do so. Similarly, Patent Document 5 describes that an inorganic insulating film made of a silicon oxynitride film or the like is disposed in the vicinity of a neutral axis when bending stress is applied to an organic EL element.

JP 2003-337549 A JP 2007-10834 A JP 2003-168556 A JP 2005-251671 A International Publication No. 2005/027582

  A glass substrate is easily broken when bent due to its properties. For this reason, suppressing the crack of a glass substrate is desired.

  An example of a problem to be solved by the present invention is to suppress cracking of a glass substrate included in a light-emitting element.

The first invention comprises a glass substrate,
An organic functional layer including a light emitting layer and formed on one side of the glass substrate;
Comprising a flexible plate-shaped part including
When the plate-like portion is bent in a predetermined bending direction, and one surface of the plate-like portion is a concave curved surface and the other surface is a convex curved surface, it is located on the concave curved surface side of both surfaces of the glass substrate. The surface to be called is the first surface,
When the thickness of the glass substrate is T,
When the plate-like portion is bent, the light emitting element applies compressive stress to a portion of the glass substrate whose distance from the first surface is L (L> T / 2) or less.

The second invention comprises a glass substrate,
An organic functional layer including a light emitting layer and formed on one side of the glass substrate;
Comprising a flexible plate-shaped part including
The whole of the glass substrate is a light emitting element located on one surface side of the plate-like part with respect to the center in the thickness direction of the plate-like part.

  The above-described object and other objects, features, and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings.

It is a typical sectional side view of the light emitting element which concerns on embodiment. 1 is a schematic side cross-sectional view of a light emitting element according to Example 1. FIG. 1 is a schematic side cross-sectional view of a light emitting element according to Example 1. FIG. 1 is a schematic side cross-sectional view of a light emitting element according to Example 1. FIG. It is a sectional side view which shows the 1st example of the layer structure of an organic functional layer. It is a sectional side view which shows the 2nd example of the layer structure of an organic functional layer. It is a figure for demonstrating the stress which arises in a plate-shaped part when a plate-shaped part is curved. 6 is a schematic side cross-sectional view of a light-emitting element according to Example 3. FIG. 6 is a schematic side cross-sectional view of a light emitting device according to Example 4. FIG. 6 is a schematic side cross-sectional view of a light-emitting element according to Example 5. FIG. 6 is a schematic exploded perspective view of a light emitting device according to Example 6. FIG. 12A is a schematic cross-sectional view of the light-emitting device according to Example 6 (when not curved), and FIG. 12B is a schematic cross-sectional view of the light-emitting device according to Example 6 (when curved). 12 (c) is a schematic side sectional view of the light emitting device according to Example 6. FIG.

  Hereinafter, embodiments will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 1 is a side sectional view of a light emitting device according to an embodiment. This light emitting element includes a flexible plate-like portion 100. The plate-like portion 100 includes a glass substrate 110 and an organic functional layer formed on one surface side of the glass substrate 110. The organic functional layer includes a light emitting layer. The configuration of the organic functional layer will be described later in Examples. When the plate-like portion 100 is bent in a predetermined bending direction, one surface 102 of the plate-like portion 100 is a concave curved surface, and the other surface 101 is a convex curved surface, the concave surface side of both surfaces of the glass substrate 110 The surface that is positioned is referred to as the first surface 111. The thickness of the glass substrate 110 is T. The distance from the first surface 111 in the glass substrate 110 when the plate-like portion 100 is bent in a predetermined bending direction, and one surface 102 of the plate-like portion 100 is a concave curved surface and the other surface 101 is a convex curved surface. , L (L> T / 2) or less (compressive stress generator 112 in FIG. 1) is subjected to compressive stress.

  In the following description, for the sake of simplicity of explanation, the positional relationship (vertical relationship, etc.) of each component of the light emitting element is assumed to be the relationship shown in each drawing. However, the positional relationship in this description is irrelevant to the positional relationship at the time of using and manufacturing the light emitting element.

  Further, in the following description, it is simply assumed that the plate-like portion 100 is bent in a predetermined bending direction so that one surface 102 of the plate-like portion 100 is a concave curved surface and the other surface 101 is a convex curved surface. The shape portion 100 is curved.

  The glass substrate 110 is made of translucent glass. The thickness of the glass substrate 110 is formed so as to have flexibility. The thickness of the glass substrate 110 is preferably about 10 μm to 200 μm, for example.

  When the glass substrate 110 is formed to a thickness of a certain degree or less, it can have a certain degree of flexibility. However, even if the glass substrate 110 is formed to be sufficiently thin, if the glass substrate 110 is bent with a large curvature exceeding the limit (with a small radius of curvature), the glass substrate 110 is cracked starting from a small scratch.

  As a result of investigation of the breakage (cracking) of the glass substrate 110 by the present inventor, it was found that the progress of cracks due to the tensile stress is dominant, and the glass substrate 110 is hardly broken by the compressive stress. Therefore, the direction of bending (curving) of the plate-like portion 100 is defined, and in the thickness direction of the glass substrate 110 in a state where the plate-like portion 100 is curved, the region is larger than half of the thickness T of the glass substrate 110. By setting the arrangement of the glass substrate 110 in the thickness direction of the plate-like portion 100 so that the compressive stress is generated, the breakage (cracking) of the glass substrate 110 can be suppressed.

  When the plate-like portion 100 is curved, tensile stress is applied to the convex curved surface side (the other surface 101 side) of the plate-like portion 100, and compressive stress is applied to the concave curved surface side (the one surface 102 side). Each occurs. The center plane C1 shown in FIG. 1 is a plane where tensile stress and compressive stress are balanced in a state where the plate-like portion 100 is curved.

  As described above, a surface on the concave curved surface side of the plate-like portion 100 among both surfaces of the glass substrate 110 in a state where the plate-like portion 100 is curved is referred to as a first surface 111. In a state where the plate-like portion 100 is curved, a compressive stress is applied to the compressive stress generating portion 112 which is a portion of the glass substrate 110 whose distance from the first surface 111 is L or less. L is larger than half of the thickness T of the glass substrate. That is, L> T / 2.

  In other words, in the thickness direction of the glass substrate 110, a region larger than half of the thickness T of the glass substrate 110 is located on the other surface 101 side with respect to the center surface C1. Therefore, compressive stress is generated in a region larger than half of the thickness T of the glass substrate 110 in the thickness direction of the glass substrate 110 in a state where the plate-like portion 100 is curved.

  In the light emitting device according to the present embodiment, the center C2 in the thickness direction of the glass substrate 110 (the center C2 of the glass substrate 110 in the thickness direction of the glass substrate 110) is the center in the thickness direction of the plate-like portion 100. (The center of the plate-like part 100 in the thickness direction of the plate-like part 100: not shown) is located on the one surface 102 side of the plate-like part 100. The center in the thickness direction of the plate-like portion 100 may or may not coincide with the center plane C1.

  The light emitting element according to this embodiment does not have a glass substrate (a glass substrate other than the glass substrate 110) at least on the other surface 101 side than the glass substrate 110. The glass substrate included in the light emitting element is preferably only the glass substrate 110.

  As described above, according to the present embodiment, the light emitting element includes the flexible plate-like portion 100 including the glass substrate 110 and the organic functional layer including the light emitting layer and formed on one surface side of the glass substrate 110. Prepare. When the plate-like portion 100 is bent in a predetermined bending direction, one surface 102 of the plate-like portion 100 is a concave curved surface, and the other surface 101 is a convex curved surface, the concave surface side of both surfaces of the glass substrate 110 The surface that is positioned is referred to as the first surface 111. The thickness of the glass substrate 110 is T. When the plate-like portion 100 is curved, a compressive stress is applied to a portion of the glass substrate 110 whose distance from the first surface 111 is L (L> T / 2) or less. That is, the arrangement of the glass substrate 110 in the thickness direction of the light emitting element is set so that the compressive stress is applied to the compressive stress generating portion 112 that is a portion having a distance from the first surface 111 of L or less in the glass substrate 110. Thereby, since destruction (cracking) of the glass substrate 110 can be suppressed, the flexibility and reliability of the plate-like portion 100 of the light emitting element can be improved.

Here, as described above, in Patent Documents 3 to 5, the stress generated in the inorganic moisture-proof layer or the like is reduced by disposing the inorganic moisture-proof layer or the like at a substantially central portion in the thickness direction of the light emitting element. Is described. For this reason, even when the light emitting element is bent in any direction, an equivalent stress is generated inside the inorganic moisture-proof layer or the like. Since the inorganic moisture-proof film is usually a very thin film having a thickness of 1 μm or less, the stress generated in the inorganic moisture-proof film can be made extremely small by the configuration described in Patent Documents 3 to 5. However, even if the glass substrate 110 is thin, it has a thickness of, for example, 10 μm or more. When the center plane C1 and the center C2 in the thickness direction of the glass substrate 110 are made to coincide with each other, the plate-like portion 100 is curved in any direction. Even in such a case, a tensile stress is generated inside the glass substrate 110. The glass substrate 110 often has microcracks, chipping of the end face, and the like. Since the glass substrate 110 is weaker in tensile stress than the inorganic moisture-proof film, the glass substrate 110 is referred to as an inorganic moisture-proof layer or the like in Patent Documents 3 to 5. It is difficult to obtain a practically sufficient radius of curvature and fracture resistance with a configuration arranged at the same position.
On the other hand, in the present embodiment, the bending direction of the light emitting element is defined as one direction, and the distance from the first surface 111 in the glass substrate 110 when the plate-like portion 100 is bent is L (L > T / 2) The arrangement of the glass substrate 110 in the thickness direction of the light emitting element is set so that compressive stress is applied to the following portions. Thereby, the tensile stress which generate | occur | produces in the glass substrate 110 can be reduced significantly. Alternatively, only the compressive stress can be generated in the glass substrate 110. As a result, the plate-like portion 100 can be curved with a smaller radius of curvature, and the fracture resistance of the glass substrate 110 can be improved.

  Similarly, the center C <b> 2 in the thickness direction of the glass substrate 110 is positioned closer to the one surface 102 of the plate-like part 100 than the center in the thickness direction of the plate-like part 100. It is possible to easily realize a configuration in which compressive stress is applied to the compressive stress generating portion 112 that is a portion having a distance L or less from the first surface 111, and to suppress breakage (cracking) of the glass substrate 110.

Example 1
The light-emitting element according to this example is different from the light-emitting element according to the above-described embodiment in the points described below, and is otherwise configured in the same manner as the light-emitting element according to the above-described embodiment.

  2 to 4 are schematic side sectional views of the light emitting device according to this example. Among these, FIG. 2 shows a schematic configuration of the plate-like portion 100. FIG. 3 shows a more detailed layer structure than FIG. FIG. 4 shows a state in which the plate-like portion 100 is fixed to the fixing member 300.

  In this embodiment, an example in which the light emitting element is a bottom emission type and light is emitted from the other surface 101 (convex curved surface) side will be described.

  As shown in FIG. 2, in the case of the present embodiment, the entire glass substrate 110 is located closer to the one surface 102 side of the plate-like portion 100 than the center C <b> 3 in the thickness direction of the plate-like portion 100.

  That is, the light emitting device according to this example includes a flexible plate-like portion including a glass substrate 110 and an organic functional layer 140 (described later) that includes the light emitting layer and is formed on one surface side of the glass substrate 110. 100, and the entire glass substrate 110 is located on the one surface 102 side of the plate-like portion 100 with respect to the center C3 in the thickness direction of the plate-like portion 100.

  Thereby, it can be expected that compressive stress is generated in the entire glass substrate 110 in a state where the plate-like portion 100 is curved as shown in FIG.

  In addition, it is preferable that the whole glass substrate 110 is located in the one surface 102 side of the plate-shaped part 100 rather than said center plane C1 (refer FIG. 1). By doing in this way, compressive stress can generate | occur | produce in the whole glass substrate 110 in the state which curved the plate-shaped part 100 like FIG.

  As shown in FIG. 3, the light emitting element includes a glass substrate 110, a first electrode 130, an organic functional layer 140, and a second electrode 150. The organic functional layer 140 is disposed between the first electrode 130 and the second electrode 150. The first electrode 130 is disposed between the organic functional layer 140 and the glass substrate 110.

  The first electrode 130 is a transparent electrode made of a metal oxide conductor such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). However, the first electrode 130 may be a metal thin film that is thin enough to transmit light.

  The second electrode 150 is a reflective electrode made of a metal layer such as Ag, Au, or Al. The second electrode 150 reflects light traveling from the organic functional layer 140 toward the second electrode 150 side. However, the second electrode 150 may be a transparent electrode made of a metal oxide conductor such as ITO or IZO, and a light reflecting layer (not shown) may be provided below the second electrode 150. Alternatively, the thickness of the metal layer constituting the second electrode 150 may be reduced so that the second electrode 150 has translucency, and a transparent light-emitting element may be used when no light is emitted.

  One of the first electrode 130 and the second electrode 150 is an anode, and the other is a cathode. The material constituting the cathode and the material constituting the anode have different work functions.

  For example, one surface (the lower surface in FIG. 4) of the glass substrate 110 and one surface (the upper surface in FIG. 1) of the first electrode 130 are in contact with each other. Further, the other surface (lower surface in FIG. 1) of the first electrode 130 and one surface (upper surface in FIG. 1) of the organic functional layer 140 are in contact with each other. Further, the other surface (lower surface in FIG. 1) of the organic functional layer 140 and one surface (upper surface in FIG. 1) of the second electrode 150 are in contact with each other. However, another layer may exist between the glass substrate 110 and the first electrode 130. Similarly, another layer may exist between the first electrode 130 and the organic functional layer 140. Similarly, another layer may exist between the organic functional layer 140 and the second electrode 150.

  The plate-like portion 100 further includes a resin layer 210 disposed on the other surface 101 side of the plate-like portion 100 with respect to the glass substrate 110. The layer thickness of the resin layer 210 is thicker than the thickness T of the glass substrate 110.

The resin layer 210 is, for example, a translucent resin. The resin layer 210 is made of, for example, any one of PEN (polyethylene naphthalate), PES (polyethersulfone), PC (polycarbonate), PET (polyethylene terephthalate), polyimide, and polyamide.
The resin layer 210 may be an organic / inorganic hybrid structure. Examples of the organic / inorganic hybrid structure include those formed by impregnating a glass fiber cloth with a resin. Also in this case, the resin layer 210 (also referred to as a resin-containing layer) is translucent.

  For example, the resin layer 210 is in contact with the surface of the glass substrate 110 opposite to the first surface 111. However, another layer may exist between the glass substrate 110 and the resin layer 210.

  The plate-like portion 100 further includes a light extraction film 220 provided on the opposite side of the resin layer 210 from the glass substrate 110 side. The light extraction film 220 is made of, for example, a microlens array sheet or a scattering sheet. For example, the light extraction film 220 is in contact with the surface of the resin layer 210 opposite to the glass substrate 110 side. However, another layer may exist between the resin layer 210 and the light extraction film 220.

  The organic functional layer 140 is disposed on the other surface 101 side of the plate-like portion 100 with respect to the glass substrate 110.

The plate-like portion 100 further has a sealing layer 160. The sealing layer 160 covers the lower surface of the second electrode 150. The sealing layer 160 is formed, for example, by sealing a layer made of an inorganic solid (SiON film, Al ₂ O ₃ film, etc.). The sealing layer 160 can be formed by, for example, CVD (Chemical Vapor Deposition) or ALD (Atomic Layer Deposition). A protective film made of an organic material may be further formed under the inorganic solid layer. Furthermore, solid sealing (for example, affixing an aluminum foil with a thermosetting epoxy adhesive) may be performed.

  As shown in FIG. 4, the light emitting device according to this example further includes a fixing member 300 having a curved surface (for example, a concave curved surface 301). The plate-like portion 100 is fixed to the fixing member 300 along the concave curve of the fixing member 300, and is curved so that one surface 102 of the plate-like portion 100 is a concave curved surface and the other surface 101 is a convex curved surface. .

  In the case of the present embodiment, the fixing member 300 is translucent. The fixing member 300 is made of a transparent acrylic plate, for example.

  In addition, the surface (upper surface in FIG. 4) on the opposite side to the concave curved surface 301 in the fixing member 300 is, for example, a convex curved surface. However, the surface of the fixing member 300 opposite to the concave curved surface 301 may be a flat surface or a surface having another shape.

  When a voltage is applied between the first electrode 130 and the second electrode 150, the light emitting layer of the organic functional layer 140 emits light. The organic functional layer 140, the first electrode 130, the glass substrate 110, the resin layer 210, the light extraction film 220, and the fixing member 300 all transmit at least part of the light emitted from the light emitting layer of the organic functional layer 140. . Part of the light emitted from the light emitting layer is emitted from the upper surface of the fixing member 300 to the outside of the light emitting element.

  Next, an example of the layer structure of the organic functional layer 140 will be described.

  FIG. 5 is a side sectional view showing a first example of the layer structure of the organic functional layer 140. The organic functional layer 140 has a structure in which a hole injection layer 141, a hole transport layer 142, a light emitting layer 143, an electron transport layer 144, and an electron injection layer 145 are stacked in this order. That is, the organic functional layer 140 is an organic electroluminescence light emitting layer. Note that instead of the hole injection layer 141 and the hole transport layer 142, one layer having the functions of these two layers may be provided. Similarly, instead of the electron transport layer 144 and the electron injection layer 145, one layer having the functions of these two layers may be provided.

  In this example, the light emitting layer 143 is, for example, a layer that emits red light, a layer that emits blue light, or a layer that emits green light. In this case, in a plan view, a region having a light emitting layer 143 that emits red light, a region having a light emitting layer 143 that emits green light, and a region having a light emitting layer 143 that emits blue light are repeatedly provided. May be. In this case, when each region emits light simultaneously, the light emitting element emits light in a single light emission color such as white.

  Note that the light-emitting layer 143 may be configured to emit light in a single emission color such as white by mixing materials for emitting a plurality of colors.

  FIG. 6 is a side sectional view showing a second example of the layer structure of the organic functional layer 140. The light emitting layer 143 of the organic functional layer 140 has a structure in which light emitting layers 143a, 143b, and 143c are stacked in this order. The light emitting layers 143a, 143b, and 143c emit light of different colors (for example, red, green, and blue). The light emitting layers 143a, 143b, and 143c emit light at the same time, so that the light emitting element emits light in a single light emission color such as white.

  Next, an example of a method for manufacturing the light emitting device according to this embodiment will be described.

  First, a light-transmitting conductive film made of a metal oxide conductor such as ITO or IZO is formed on the lower surface (first surface 111) of the glass substrate 110 by sputtering or the like, and this is patterned by etching. One electrode 130 is formed.

  Next, the organic functional layer 140 is formed by depositing an organic material on the lower surface of the first electrode 130.

  Next, a second electrode 150 is formed on the lower surface of the organic functional layer 140 by depositing a metal material such as Ag, Au, or Al in a desired pattern by an evaporation method using a mask or the like.

  Next, the sealing layer 160 is formed on the lower surface of the second electrode 150.

  In addition, you may form a bus line and a partition part at an appropriate timing as needed. The bus line is made of a material having a resistance lower than that of the first electrode 130 and is provided so as to be in contact with the first electrode 130. The partition wall partitions the organic functional layer 140 into a plurality of regions in a plan view and is configured by an insulating film.

  According to this example, in addition to the same effects as the above embodiment, the following effects can be obtained.

  Since the entire glass substrate 110 is located on the one surface 102 side of the plate-like portion 100 with respect to the center C3 in the thickness direction of the plate-like portion 100, the glass substrate 110 is curved in a state where the plate-like portion 100 is curved. It can be expected that compressive stress is generated throughout. Therefore, the breakage of the glass substrate 110 can be further suppressed.

  The plate-like portion 100 further includes a resin layer 210 disposed on the other surface 101 side of the plate-like portion 100 with respect to the glass substrate 110, and the layer thickness of the resin layer 210 is thicker than the thickness T of the glass substrate 110. Therefore, it is possible to easily realize a configuration in which the entire glass substrate 110 is positioned closer to the one surface 102 than the center C3 in the thickness direction of the plate-like portion 100.

  The light emitting element further includes a fixing member 300 having a curved surface (for example, a concave curved surface 301). The plate-like portion 100 is fixed to the fixing member 300 along the curved surface of the fixing member 300, and one surface 102 of the plate-like portion 100. Is a concave curved surface, and the other surface 101 is curved to be a convex curved surface. Thereby, the direction of curvature of the plate-like portion 100 can be maintained constant. In addition, the direction of the curvature of the plate-like portion 100 is a direction in which the destruction of the glass substrate 110 is suppressed.

  Since the curved surface of the fixing member 300 is the concave curved surface 301, the plate-like portion 100 is pressed against the concave curved surface 301 of the fixing member 300 by the elastic force that the plate-like portion 100 tries to restore to a flat shape. Therefore, even if the plate-like portion 100 is not firmly fixed to the fixing member 300, it is easy to maintain the state where the plate-like portion 100 is stuck to the fixing member 300. Moreover, since the surface (light emitting surface) on the light extraction film 220 side exposed to the user side is covered with the fixing member 300, the light emitting element can be made to have a structure resistant to external impacts.

  In the first embodiment, the example in which the fixing member 300 is disposed only on the other surface 101 side of the plate-like portion 100 has been described. However, the concave curved surface and the convex curved surface of the first fixing member having a concave curved surface are described. The plate-like portion 100 may be sandwiched and fixed by the convex curved surface of the second fixing member. In this case, both surfaces of the plate-like portion 100 can be protected by the first fixing member and the second fixing member, respectively.

(Example 2)
The configuration of the plate-like portion 100 of the light emitting device according to this example is the same as that of Example 1 described above. In the present embodiment, a model of stress distribution in the glass substrate 110 will be described with respect to a specific structure of the plate-like portion 100.

  FIG. 7 is a diagram for explaining the stress generated in the plate-like portion 100 when the plate-like portion 100 is bent. In FIG. 7, the region R1 shows the stress distribution in the plate-like portion 100, the region R2 shows the width (width b) in the direction perpendicular to the thickness direction of each layer in the plate-like portion 100, and the region R3 shows the plate The Young's modulus (longitudinal elastic modulus) E of each layer in the shaped part 100 is shown. In each region R1 to R3, the vertical axis is the thickness direction position y. The horizontal axis of the region R1 is the magnitude of stress, the horizontal axis of the region R2 is the width b, and the horizontal axis of the region R3 is the Young's modulus E.

  Here, the center plane C1 shown in FIG. 2 is a plane where the tensile stress and the compressive stress are balanced in a state where the plate-like portion 100 is curved.

  When the width b and Young's modulus E are functions of the position y in the thickness direction of the light emitting element, and the light emitting element is located from y = 0 to y = h (that is, when the thickness of the light emitting element is h), light emission The position λ of the center plane C1 in the thickness direction of the element can be calculated by the following formula 1.

  Although the width b of the organic functional layer 140 and the sealing layer 160 is slightly smaller than the width b of the glass substrate 110, it can be almost ignored and can be made almost constant in an actual light emitting device.

  The stress σ generated in the plate-like portion 100 in a state where the plate-like portion 100 is bent with a certain curvature can be calculated by the following formula 2. In Equation 2, ρ is the radius of curvature of the plate-like portion 100.

  As shown in Equation 2 above, the stress σ is proportional to the distance from the center plane C1 and the Young's modulus, and inversely proportional to the curvature radius ρ.

  Here, as shown in a region R1 in FIG. 7, in the plate-like portion 100, a tensile stress TL is generated on the convex side of the center plane C1, and a compressive stress CS is generated on the concave side.

  The position λ of the center plane C1 in the case where the light emitting element is composed of three layers can be calculated by the following Expression 3.

Here, as an example, the thickness of each layer in the plate-like portion 100 is as follows.
Thickness t _{1 of the} portion including the first electrode 130, the organic functional layer 140, the second electrode 150, and the sealing layer 160 = 5 μm
Thickness of glass substrate 110 t ₂ = 50 μm
Resin layer 210 thickness t ₃ = 200 μm
Thickness t ₄ of light extraction film 220 = 100 μm

Moreover, the Young's modulus of each layer in the plate-like portion 100 is as follows as an example.
Young's modulus E _{1 of the} portion including the first electrode 130, the organic functional layer 140, the second electrode 150, and the sealing layer 160 = 3 GPa
Young's modulus E ₂ of glass substrate 110 = 70 GPa
Young's modulus E ₃ = 6 GPa of the resin layer 210
Young's modulus E ₄ of the light extraction film 220 = 3 GPa

  The resin layer 210 is a substrate made of PEN. The first electrode 130 is made of ITO. The sealing layer 160 includes a SiON CVD film and a protective film made of an ultraviolet curable resin.

  Under these conditions, the position λ of the center plane C1 is 76 μm from the above equation (3). Further, the position of the center C2 (see FIG. 1) in the thickness direction of the glass substrate 110 is 46 μm, and the center C2 is arranged at a position shifted from the position λ of the center plane C1 toward the other surface 101 (concave curved surface). Has been. Further, the upper surface of the glass substrate 110 is also arranged at a position shifted from the position λ of the center plane C1 by 21 μm toward the other surface 101 (concave surface). That is, the whole glass substrate 110 receives compressive stress in a state where the plate-like portion 100 is curved.

  Here, as understood from the study of the present inventors, the breakage (cracking) of the glass substrate 110 is dominated by the progress of cracks due to tensile stress, and the glass substrate 110 is not easily broken by compressive stress.

  When the plate-like portion 100 of the light-emitting element of this example is curved in a direction opposite to that in FIG. 2 (a direction in which the sealing layer 160 side is a convex curved surface), a glass substrate is formed at a stage where φ80 mm (curvature radius is 40 mm). Cracks occurred at 110. On the other hand, when the plate-like portion 100 of the light-emitting element of this example is bent in the direction of FIG. 2, that is, in the specified bending direction, generation of cracks in the glass substrate 110 can be confirmed even when φ10 mm (curvature radius is 5 mm). There wasn't.

  In this way, the bending direction of the plate-like portion 100 is limited to one direction, and the glass substrate 110 is shifted from the center surface C1 to the other surface 101 (concave surface) side, so that half of the glass substrate 110 is placed. The above portions can be subjected to compressive stress. As a result, even when the plate-like portion 100 is bent with a high curvature, the glass substrate 110 can be prevented from being broken.

  According to the present embodiment, the same effect as that of the first embodiment can be obtained.

  In addition, when the light emitting surface side is bent convexly as in the present embodiment and the first embodiment described above, the center surface C1 needs to be closer to the light emitting surface side than the glass substrate 110. Therefore, a resin layer 210 having a relatively high Young's modulus is arranged on the light emitting surface side of the glass substrate 110, and a light extraction film 220 having a certain thickness is provided. Further, as the sealing layer 160, film sealing with a small thickness is used.

  In the present embodiment, the example in which the entire glass substrate 110 is disposed at a position shifted from the central plane C1 toward the concave curved surface, and the entire glass substrate 110 receives compressive stress has been described. However, if the center C2 (see FIG. 1) in the thickness direction of the glass substrate 110 is shifted to the concave side from the center plane C1, a certain effect can be expected. For example, in an example in which a resin layer 210 (t2 = 100 μm, E2 = 6 GPa) is laminated on a glass substrate 110 (t1 = 50 μm, E1 = 70 GPa), the center plane is λ = 36 μm and is located inside the glass substrate 110. Under this condition, when the plate-like portion 100 is bent in the direction opposite to that shown in FIG. 2, the glass substrate 110 is not destroyed until the curvature is 1/3 when the plate-like portion 100 is bent in the direction shown in FIG. The shape portion 100 could be bent. This is because, even if the plate-like portion 100 is curved in any direction, tensile stress is applied to the convex curved surface side of the glass substrate 110, but as shown in Equation 2, the stress decreases as the distance from the center plane C1 decreases. Therefore, it can be considered that the tensile stress at the same curvature is smaller in the case of bending in the direction of FIG. 2 than in the case of bending in the direction opposite to that in FIG.

(Example 3)
FIG. 8 is a schematic cross-sectional side view of the light emitting device according to Example 3. In the above-described Examples 1 and 2 (FIG. 3), the example in which the light emitting element is the bottom emission type and the light is emitted from the other surface 101 (convex curved surface) side has been described. On the other hand, in this embodiment, an example in which the light emitting element is a bottom emission type and light is emitted from one surface 102 (concave surface) side will be described.

  In the first and second embodiments, the glass substrate 110, the first electrode 130, the organic functional layer 140, the second electrode 150, and the sealing layer 160 are arranged in this order on one surface 102 side with respect to the resin layer 210. ing. On the other hand, in this embodiment, the sealing layer 160, the second electrode 150, the organic functional layer 140, the first electrode 130, the glass substrate 110, and the light extraction film are formed on one surface 102 side with the resin layer 210 as a reference. 220 are arranged in this order. Further, the upper surface of the resin layer 210 is the other surface 101, and the lower surface of the light extraction film 220 is the one surface 102.

  However, when the plate-like portion 100 is curved, the point where the compressive stress is applied to the portion of the glass substrate 110 whose distance from the first surface 111 is L (L> T / 2) or less is the above-described Example 1. Same as 2. Further, the arrangement of the glass substrate 110 with respect to the center plane C1 and the arrangement of the glass substrate 110 with respect to the center C3 in the thickness direction of the plate-like portion 100 are the same as in the first and second embodiments. Further, the light emitting element may include the fixing member 300 described above.

  In the case of the present embodiment, the resin layer 210 does not need to be translucent.

  When a voltage is applied between the first electrode 130 and the second electrode 150, the light emitting layer of the organic functional layer 140 emits light. Light from the light emitting layer passes through the first electrode 130, the glass substrate 110, and the light extraction film 220 in this order, and is emitted from the lower surface of the light extraction film 220 to the outside of the light emitting element.

  According to the present embodiment, the same effects as those of the first and second embodiments can be obtained.

  In this embodiment, it is preferable to form the light extraction film 220 as thin as possible. Alternatively, it is also preferable to omit the light extraction film 220. Moreover, as the sealing layer 160, it is also preferable to use solid sealing having a thickness larger than that of the film sealing.

Example 4
FIG. 9 is a schematic cross-sectional side view of a light emitting device according to Example 4. In the above Examples 1 and 2 (FIG. 3), the example in which the light emitting element is the bottom emission type has been described. In contrast, in this embodiment, an example in which the light emitting element is a top emission type will be described. In this embodiment, an example in which light is emitted from the other surface 101 (convex curved surface) side will be described.

  In the first and second embodiments, the glass substrate 110, the first electrode 130, the organic functional layer 140, the second electrode 150, and the sealing layer 160 are arranged in this order on one surface 102 side with respect to the resin layer 210. ing. On the other hand, in this embodiment, the sealing layer 160, the first electrode 130, the organic functional layer 140, the second electrode 150, and the glass substrate 110 are arranged in this order on the one surface 102 side with the resin layer 210 as a reference. Has been. The upper surface of the resin layer 210 is the other surface 101, and the lower surface of the glass substrate 110 is the one surface 102.

  However, when the plate-like portion 100 is curved, the point where the compressive stress is applied to the portion of the glass substrate 110 whose distance from the first surface 111 is L (L> T / 2) or less is the above-described Example 1. Same as 2. Further, the arrangement of the glass substrate 110 with respect to the center plane C1 and the arrangement of the glass substrate 110 with respect to the center C3 in the thickness direction of the plate-like portion 100 are the same as in the first and second embodiments. Further, the light emitting element may include the fixing member 300 described above.

  Note that the sealing layer 160 is translucent.

  When a voltage is applied between the first electrode 130 and the second electrode 150, the light emitting layer of the organic functional layer 140 emits light. Light from the light emitting layer passes through the first electrode 130, the sealing layer 160, the resin layer 210, and the light extraction film 220 in this order, and is emitted from the upper surface of the light extraction film 220 to the outside of the light emitting element.

  According to the present embodiment, the same effects as those of the first and second embodiments can be obtained.

(Example 5)
FIG. 10 is a schematic sectional side view of a light emitting device according to Example 5. In the above Examples 1 and 2 (FIG. 3), the example in which the light emitting element is the bottom emission type has been described. In contrast, in this embodiment, an example in which the light emitting element is a top emission type will be described. In this embodiment, an example in which light is emitted from the other surface 101 (concave surface) side will be described.

  In the first and second embodiments, the glass substrate 110, the first electrode 130, the organic functional layer 140, the second electrode 150, and the sealing layer 160 are arranged in this order on one surface 102 side with respect to the resin layer 210. ing. On the other hand, in the present embodiment, the glass substrate 110, the second electrode 150, the organic functional layer 140, the first electrode 130, the sealing layer 160, and the light extraction film are formed on one surface 102 side with the resin layer 210 as a reference. 220 are arranged in this order. Further, the upper surface of the resin layer 210 is the other surface 101, and the lower surface of the light extraction film 220 is the one surface 102.

  However, when the plate-like portion 100 is curved, the point where the compressive stress is applied to the portion of the glass substrate 110 whose distance from the first surface 111 is L (L> T / 2) or less is the above-described Example 1. Same as 2. Further, the arrangement of the glass substrate 110 with respect to the center plane C1 and the arrangement of the glass substrate 110 with respect to the center C3 in the thickness direction of the plate-like portion 100 are the same as in the first and second embodiments. Further, the light emitting element may include the fixing member 300 described above.

  In the case of the present embodiment, the resin layer 210 does not need to be translucent. On the other hand, the sealing layer 160 is translucent.

  When a voltage is applied between the first electrode 130 and the second electrode 150, the light emitting layer of the organic functional layer 140 emits light. Light from the light emitting layer passes through the first electrode 130, the sealing layer 160, and the light extraction film 220 in this order, and is emitted from the lower surface of the light extraction film 220 to the outside of the light emitting element.

  According to the present embodiment, the same effects as those of the first and second embodiments can be obtained.

  In this embodiment, it is preferable to form the light extraction film 220 as thin as possible. Alternatively, it is also preferable to omit the light extraction film 220. Further, as the sealing layer 160, it is preferable to use film sealing with a small thickness.

(Example 6)
FIG. 11 is a schematic exploded perspective view of the light emitting device according to Example 6. FIG. 12A is a schematic cross-sectional view of the light-emitting device according to Example 6 (when not curved), and FIG. 12B is a schematic cross-sectional view of the light-emitting device according to Example 6 (when curved). 12 (c) is a schematic side sectional view of the light emitting device according to Example 6. FIG. The light emitting device according to this example is different from the light emitting device according to Example 1 in the points described below, and is configured in the same manner as the light emitting device according to Example 1 in other points. .

  The plate-like portion 100 of the light-emitting element according to the present embodiment is configured in the same manner as the plate-like portion 100 of any of the first to fifth embodiments.

  The light emitting device according to this example includes a fixing member 400 instead of the fixing member 300 (FIG. 4). The fixing member 400 can be plastically deformed, and is fixed to the other surface 101 side of the plate-like portion 100 (FIG. 12A). Then, the plate-like portion 100 is curved together with the fixing member 400 so that the other surface 101 of the plate-like portion 100 is a convex curved surface, and the other surface 101 is a concave curved surface. It is held in a curved state (FIGS. 12B and 12C).

  That is, by fixing the fixing member 400 plastically, the fixing member 400 is held in the shape after plastic deformation. Further, since the flexible plate-like portion 100 is restrained by the fixing member 400, the plate-like portion 100 is held by the curved member by the fixing member 400.

  Thus, in this embodiment, the fixing member 400 is plastically deformed into a shape having a curved surface by curving the fixing member 400 together with the plate-like portion 100.

  More specifically, for example, the plate-like portion 100 has a rectangular shape. On the other hand, the fixing member 400 is formed in a rectangular frame shape of the plate-like portion 100.

  The fixing member 400 has four linear plate portions 401 to 404 extending along each side of the plate portion 100. Of these, the plate-like portion 401 and the plate-like portion 403 face each other in parallel, and the plate-like portion 402 and the plate-like portion 404 face each other in parallel. Further, the plate-like portions 402 and 403 are orthogonal to the plate-like portions 401 and 403. A rectangular opening 400 a is formed at the center of the fixing member 400.

  For example, as shown in FIGS. 12B and 12C, by bending the plate-like portions 401 and 403 in an arc shape and by bending the plate-like portion 100, the plate-like portions 401 and 403 are plastically deformed, and the plate The shape portion 100 is held in a curved state.

  That is, the fixing member 400 includes a first portion (a plate-like portion 401) that extends along the first side of the plate-like portion 100 and a second side that faces the first side of the plate-like portion 100. A second portion (plate-like portion 402) that extends. The first portion and the second portion are each curved in an arc shape.

  In the case of a type that emits light from the other surface 101 side of the plate-like portion 100 (when the plate-like portion 100 is the above-described embodiment 1, 2, or 4), it is suitable through the opening 400a of the fixing member 400. Can emit light.

  In addition, even when the plate-like portion 100 has any of the configurations of the first to fifth embodiments, heat can be suitably radiated through the opening 400a of the fixing member 400.

  The fixing member 400 can be made of metal, for example. Although the method of fixing the plate-like part 100 to the fixing member 400 is not limited, for example, it can be fixed using an adhesive.

  According to the present embodiment, the same effects as in the first embodiment (excluding the effects obtained by the fixing member 300) can be obtained, and the following effects can be obtained.

  By bending the fixing member 400 together with the plate-like portion 100, the fixing member 400 is plastically deformed into a shape having a curved surface. Therefore, the fixed member 400 holds the plate-like portion 100 in a curved state in which one surface 102 is a concave curved surface and the other surface 101 is a convex curved surface. That is, the bending direction of the plate-like portion 100 can be kept constant by the fixing member 400. In addition, the direction of the curvature of the plate-like portion 100 is a direction in which the destruction of the glass substrate 110 is suppressed.

  Further, in the case of this example, in order to curve the entire light emitting element including the fixing member 400 and the plate-like portion 100, the above-described center plane C1 is closer to the fixing member 400 (see FIG. The same effect as moving to b) and (upper side in (c)) can be obtained. As a result, the compressive stress generated in the glass substrate 110 can be increased in a state where the plate-like portion 100 is curved. In other words, the same effect as that of increasing the layer thickness of the resin layer 210 in Example 1 can be obtained.

  Here, as the Young's modulus of the material disposed on the convex surface side of the light emitting element is higher, there is an effect of moving the center plane C1 to the convex surface side of the light emitting element. As shown in the above formula 1, even if the thickness (width b) of the fixing member 400 is small, the effect is sufficiently obtained if the Young's modulus of the fixing member 400 is high.

  Further, the plate-like portion 100 has a rectangular shape, and the fixing member 400 includes a first portion (plate-like portion 401) extending along the first side of the plate-like portion 100 and a first side of the plate-like portion 100. And a second portion (plate-like portion 402) extending along the second side opposite to the first side. The first portion and the second portion are each curved in an arc shape. Therefore, the fixing member 400 holds the plate-like portion 100 in a curved state in which one surface 102 is a concave curved surface and the other surface 101 is a convex curved surface.

  As mentioned above, although embodiment and the Example were described with reference to drawings, these are illustrations of this invention and can also employ | adopt various structures other than the above.

  For example, in the above description, an example in which compressive stress is generated in the glass substrate 110 by applying an external force to the plate-like portion 100 to bend the plate-like portion 100 has been described, but by applying chemical treatment to the glass substrate 110, A compressive stress may be generated in the glass substrate 110.

Claims (7)

A light emitting device,
A glass substrate;
An organic functional layer including a light emitting layer and formed on one side of the glass substrate;
A resin layer thicker than the thickness of the glass substrate;
Have
The light emitting element is fixed along the curved surface of the fixing member having a curved surface, and is curved so that the surface side on which the resin layer is formed with respect to the glass substrate is a convex curved surface,
The center of the glass substrate in the thickness direction is a light emitting element located on the concave surface side of the center of the light emitting element in the thickness direction . The light emitting device according to claim 1,
The center of the light emitting element in the thickness direction is a light emitting element located in the resin layer. The light emitting device according to claim 1,
The center of the light emitting element in the thickness direction is a light emitting element located on the glass substrate. In the light emitting element as described in any one of Claims 1-3,
The glass substrate has the other surface opposite to the one surface and the one surface,
The resin layer is a light emitting element located on the one surface side. In the light emitting element as described in any one of Claims 1-4,
Light emitted from the light emitting layer is emitted to the outside through the resin layer. In the light emitting element as described in any one of Claims 1-3,
The glass substrate has the other surface opposite to the one surface and the one surface,
The resin layer is a light emitting element located on the other surface side. In the light emitting device according to any one of claims 1, 2, 3, and 6,
The light emitting element in which the light of the said light emitting layer is radiated | emitted on the opposite side to the said glass substrate and the said resin layer.

Images