JP4533963B2 - Organic EL light emitting device - Google Patents

Description

  The present invention relates to an organic EL light emitting device, an organic EL lighting device, and a current injection method for the organic EL light emitting device, and in particular, organic EL light emission for supplying current to a cylindrical organic EL light emitting device having an organic EL light emitting element formed on the inner surface. The present invention relates to a current injection method for an apparatus, an organic EL lighting device, and an organic EL light emitting device.

  In recent years, a cylindrical surface emitting device in which an organic EL (Electro Luminescence) element is formed has been proposed. For example, according to Japanese Patent Application Laid-Open No. 2007-73403 (Patent Document 1), a surface emitting device includes a cylindrical transparent base material (tube) and an organic EL element formed on the transparent base material. The organic EL element has a transparent electrode, an organic EL layer, and a metal electrode that are sequentially formed inside the tube. As the transparent electrode, a metal thin film, an oxide of any one of indium, zinc and tin, or a nitride of titanium is used. As the metal electrode, aluminum, gold, silver, copper, or the like is used.

  Further, for example, in Japanese Patent Application Laid-Open No. 2003-142252 (Patent Document 2), a tubular light emitting device including a tubular non-moisture permeable transparent substrate (tube) and an organic EL element formed on the inner peripheral surface thereof. Is disclosed. The organic EL element includes a positive electrode layer, a light emitting functional layer, and a negative electrode layer. It is disclosed that the positive electrode layer is formed from a metal having a high work function, and the negative electrode layer is formed from a metal having a low work function.

  This organic EL element has a diode characteristic and emits light when a voltage is applied to a transparent electrode and a metal electrode to inject a current. That is, the organic EL element generally emits light by supplying a direct current.

JP 2007-73403 A JP 2003-142252 A

  The devices disclosed in Patent Documents 1 and 2 have a problem in that the light emission luminance varies in the longitudinal direction of the tube. In addition, the above Patent Documents 1 and 2 have not been devised for this problem.

  The present invention has been made in view of the above problems, and an object thereof is to provide an organic EL light-emitting device, an organic EL lighting device, and a current injection method for the organic EL light-emitting device that suppress variation in light emission luminance. .

  The organic EL light emitting device of the present invention includes a tube, a first electrode layer, an organic material layer, and a second electrode layer. The tube has translucency. The first electrode layer is formed inside the tube along the direction in which the tube extends, and has translucency. The organic material layer is formed inside the first electrode layer along the direction in which the tube extends, and emits light when a voltage is applied. The second electrode layer is formed inside the organic layer along the direction in which the tube extends. One of the first electrode layer and the second electrode layer is an anode, and the other is a cathode. The electrical resistance value of the first electrode layer and the electrical resistance value of the second electrode layer are the same.

  According to the organic EL light emitting device of the present invention, the electric resistance value per unit length along the extending direction of the first and second electrode layers is the same. For this reason, when a current is supplied to one of the anodes of the first electrode layer and the second electrode layer and a current is taken out from the other cathode, they face each other along the extending direction of the first electrode layer and the second electrode layer. The same voltage drop occurs at the position where That is, the potential difference between the first electrode layer and the second electrode layer along the longitudinal direction of the tube is the same. For this reason, a uniform electric current can be sent along the longitudinal direction of the tube from the first electrode layer and the second electrode layer to the organic layer. Therefore, variation in light emission luminance can be suppressed.

  The above-mentioned “the electric resistance value of the first electrode layer and the electric resistance value of the second electrode layer are the same” means that the electric resistance value of the first electrode layer and the electric resistance value of the second electrode layer are numerical values. The case where it is completely the same and the case where the numerical values are regarded as substantially the same are included. The case where the numerical values are regarded as substantially the same is, for example, that the electrical resistance value of the second electrode layer is in the range of 90% to 110% of the electrical resistance value of the first electrode layer.

  Preferably, in the organic EL light emitting device, a first external electrode electrically connected to the plurality of locations of the first electrode layer, and a second external electrode electrically connected to the plurality of locations of the second electrode layer are further provided. I have. The distances from the first external electrode to the plurality of locations of the first electrode layer are the same. The distances from the second external electrode to the plurality of locations of the second electrode layer are the same.

  Thereby, the resistance required for electrical connection between the first external electrode and the first electrode layer can be made uniform. Further, the resistance required for electrical connection between the second external electrode and the second electrode layer can be made uniform. For this reason, among the resistances of the first electrode layer and the second electrode layer, the resistance in the direction intersecting with the direction in which the tube extends can be made more uniform. Therefore, variation in the light emission luminance in the circumferential direction can be further suppressed.

  Preferably, in the organic EL light emitting device, the first external electrode is connected at one end of the first electrode layer, the second external electrode is connected at the other end of the second electrode layer, and the first electrode layer One end portion is either the inner peripheral side or the outer peripheral side of the tube, and the other end portion of the second electrode layer is opposite to the one end portion of the first electrode layer in the circumferential direction of the tube.

  As a result, a uniform current can flow from the first electrode layer and the second electrode layer to the organic layer. Therefore, it is possible to realize an organic EL light emitting device that further suppresses variations in light emission luminance.

  Preferably, the organic EL light emitting device further includes an extraction electrode positioned between the organic material layer and the cathode and disposed along the direction in which the tube extends.

  Thereby, uniform electrons can be emitted from the cathode by applying a voltage to the extraction electrode. For this reason, a uniform electric current can be inject | poured into an organic substance layer because an electron goes straight from a cathode to an organic substance layer via an extraction electrode. Therefore, variation in emission luminance can be further suppressed.

  In the organic EL light emitting device, preferably, a plurality of light emitting elements including the first electrode layer, the organic material layer, and the second electrode layer are formed in the tube, and the light emitting elements are connected in series to each other.

  Thereby, since the length of the 1st and 2nd electrode layer can be shortened, the electrical resistance of the 1st and 2nd electrode layer of the direction where a pipe extends can be made small. Therefore, variation in emission luminance can be further suppressed.

  Further, by connecting the light emitting elements in series with each other, the voltage increases, but the current flowing through the light emitting elements can be decreased. Since the power consumption is the product of voltage and current, the power consumption does not change even if the light emitting elements are connected in series with each other. However, by reducing the current, Joule heat is generated when current flows through the first and second electrode layers. Can be suppressed. That is, by dividing large-area light-emitting elements and connecting them in series, low-voltage and large-current light emission can be converted into high-voltage and low-current light emission. Although the light emission output does not change, the generation of Joule heat in the first and second electrode layers can be suppressed by reducing the current.

  Further, by dividing the light emitting elements and connecting them in series, even if one light emitting element is short-circuited, current is supplied to the other light emitting elements, so that light emission can be continued.

  In the organic EL light emitting device, preferably, the second electrode layer is formed along the direction in which the tube extends, the third electrode layer of the same electrode as the first electrode layer, and the tube extends inside the third electrode layer. A second organic layer that is formed along the direction and emits light when a voltage is applied; and a fourth electrode that is formed along the direction in which the tube extends inside the second organic layer and is the same electrode as the second electrode layer And further comprising a layer. The electric resistance value of the third electrode layer and the electric resistance value of the fourth electrode layer are the same. The polarities of the organic layer and the second organic layer are in the same direction. The first electrode layer and the fourth electrode layer are electrically connected.

  Since the first light-emitting element (organic EL element) including the first electrode layer, the organic material layer, and the second electrode layer has diode characteristics, current flows only in one direction. A second light emitting device including a third electrode layer, a second organic material layer, and a fourth electrode layer is stacked in two stages in series with the first light emitting device, between the first electrode layer and the second electrode layer, and third By applying an AC voltage between the electrode layer and the fourth electrode layer, the first and second light emitting elements can emit light alternately. When an AC voltage is applied, the direction of current flowing between the first electrode layer and the second electrode layer and between the third electrode layer and the fourth electrode layer changes, so that variation in emission luminance is suppressed. be able to.

  Further, since a general organic EL light emitting device is driven by a direct current, when an alternating voltage is applied, it is necessary to convert the alternating current into direct current. In the AC drive, there is a slight flicker at the timing when the positive voltage and the negative voltage are switched. However, the first and second light emitting elements do not require a ballast or an AC-DC converter, and power loss caused by these can be reduced.

  The “third electrode layer of the same electrode as the first electrode layer” means that when the first electrode layer is an anode, the third electrode layer is also an anode, and when the first electrode layer is a cathode, the third electrode layer is the third electrode layer. The electrode layer is also a cathode. The “fourth electrode layer of the same electrode as the second electrode layer” means that when the second electrode layer is an anode, the fourth electrode layer is also an anode, and when the second electrode layer is a cathode, the fourth electrode layer is the fourth. The electrode layer is also a cathode.

  Preferably, the organic EL light emitting device further includes a light-transmitting substrate that is formed along the direction in which the tube extends inside the tube and outside the first electrode layer.

  Thus, all of the above items can be applied even when a flexible substrate is formed on the inner surface of the tube.

  Preferably, the organic EL light emitting device includes a plurality of laminates each including a substrate, a first electrode layer, an organic material layer, and a second electrode layer, and the plurality of laminates are wound so as to overlap in a cylindrical shape, A strip-shaped auxiliary electrode is further provided to connect each other and the second electrode layers.

  As described above, even when a flexible substrate having translucency is mounted by being wrapped around the inner surface of the tube in multiple layers, if the belt-like auxiliary electrode is wound on the substrate, the auxiliary electrode is mounted on the substrate. All of the above items can be applied. By wrapping the substrate in multiple layers, the light emission area can be increased.

  Preferably, the organic EL light emitting device further includes a linear or wire mesh metal electrode connected to the first electrode layer and reducing the electric resistance of the first electrode layer.

  Since the 1st electrode layer has translucency, electric resistance is large compared with the usual metal. By providing a straight or wire mesh metal electrode on the outside or inside of the first electrode layer, the electrical resistance can be reduced.

  The organic EL lighting device of the present invention includes any of the plurality of organic EL light emitting devices described above and a coupler that connects the plurality of organic EL light emitting devices.

  According to the organic EL lighting device of the present invention, the organic EL light-emitting device that suppresses the variation in emission luminance is provided. Therefore, it is possible to realize an organic EL lighting device that suppresses variations in light emission luminance.

The current injection method for an organic EL light emitting device of the present invention is a method for injecting a current into any of the above organic EL light emitting devices, and includes the following steps. First, current is supplied to the anode. Then, a current is passed along the direction in which the tube extends, and the current is extracted from the cathode.

  According to the current injection method of the organic EL light emitting device of the present invention, the electrical resistance value of the first electrode layer and the electrical resistance value of the second electrode layer are the same, so the electrical resistance value of the anode and the electrical resistance value of the cathode Is the same. The organic material layer is close to an insulator, and the electrical resistance value is much larger than the electrical resistance values of the anode and cathode, so that it is close to a cylindrical capacitor. For this reason, a uniform electric current can be sent along the longitudinal direction of the tube.

  As described above, according to the present invention, since a uniform current can be supplied to the organic layer in the direction in which the tube extends, it is possible to suppress variations in light emission luminance.

BRIEF DESCRIPTION OF THE DRAWINGS It is an external view which shows schematically the structure of the light-emitting device in Embodiment 1 of this invention, (A) is a top view, (B) is a side view. It is sectional drawing which followed the II-II line in FIG. 1 (B). It is a schematic diagram when it sees from the III-III line | wire in FIG. It is a schematic diagram when it sees from the IV-IV line | wire in FIG. 1 is an equivalent circuit diagram of an organic EL light emitting device in Embodiment 1 of the present invention. It is a schematic sectional drawing of the organic electroluminescent light emitting device in Embodiment 2 of this invention. It is an equivalent circuit diagram of the organic EL light emitting device in the second embodiment of the present invention. It is a side view which shows roughly the structure of the organic electroluminescent illuminating device in Embodiment 3 of this invention. It is a top view which shows roughly the structure of the organic electroluminescent illuminating device in Embodiment 3 of this invention. It is the equivalent circuit schematic of the organic electroluminescent illuminating device in Embodiment 3 of this invention. It is the equivalent circuit schematic of the organic electroluminescent illuminating device in Embodiment 3 of this invention. It is an external view which shows roughly the structure of the organic electroluminescent illuminating device in the modification 1 of Embodiment 3 of this invention. It is an external view which shows roughly the structure of the organic electroluminescent illuminating device in the modification 2 of Embodiment 3 of this invention. It is an external view which shows roughly the structure of the organic electroluminescent illuminating device in the modification 3 of Embodiment 3 of this invention. It is an external view which shows roughly the structure of the organic electroluminescent illuminating device in the modification 4 of Embodiment 3 of this invention. It is an external view which shows roughly the structure of the organic electroluminescent illuminating device in the modification 5 of Embodiment 3 of this invention. It is sectional drawing of the organic electroluminescent light emitting device in the modification 1 of Embodiment 1 of this invention. It is an equivalent circuit diagram of the organic EL light emitting device in Modification 1 of Embodiment 1 of the present invention. (A) And (B) is a conceptual diagram of the organic electroluminescent light emitting device in the modification 1 of Embodiment 1 of this invention. It is sectional drawing of the organic electroluminescent light emitting device in the modification 2 of Embodiment 1 of this invention. FIG. 6 is an equivalent circuit diagram of an organic EL light emitting device in Modification 2 of Embodiment 1 of the present invention. FIG. 6 is an equivalent circuit diagram of an organic EL light emitting device in Modification 2 of Embodiment 1 of the present invention. It is sectional drawing of a structure of the organic electroluminescent light emitting device of the modification 3 of Embodiment 1 of this invention. It is a schematic diagram which shows the board | substrate of the modification 3 of Embodiment 1 of this invention. It is a schematic diagram which shows the board | substrate of the modification 3 of Embodiment 1 of this invention. It is a schematic diagram which shows the manufacturing process of the organic electroluminescent light emitting device of the modification 3 of Embodiment 1 of this invention. It is sectional drawing of a structure of the organic electroluminescent light emitting device of the modification 4 of Embodiment 1 of this invention. It is a schematic diagram which shows the flexible substrate and auxiliary electrode of the modification 4 of Embodiment 1 of this invention. It is a schematic diagram which shows the flexible substrate and auxiliary electrode of the modification 4 of Embodiment 1 of this invention. It is a schematic diagram which shows the metal electrode of the modification 5 of Embodiment 1 of this invention. It is a schematic diagram which shows the metal electrode of the modification 5 of Embodiment 1 of this invention.

Embodiments of the present invention will be described below.
(Embodiment 1)
First, the structure of the light emitting device of this embodiment will be described. 1 and 2 are an external view and a cross-sectional view schematically showing the configuration of the light-emitting device according to Embodiment 1 of the present invention.

  With reference to FIG. 1 and FIG. 2, the organic EL light-emitting device 130 of this Embodiment is the cylindrical tube 1 (base material), the organic EL element 12, the sealing part 110, electrode 112a, 112b, wiring 113a, 113b and desiccants 127a, 127b.

  The cylindrical tube 1 is a tube having a hollow portion extending in the length direction (LD direction in the drawing). That is, the cylindrical tube 1 has a tube shape. Moreover, the cylindrical tube 1 has translucency. Specifically, the cylindrical tube 1 is a tube made of, for example, soda lime glass and having a diameter of 50 mm, a length of 540 mm, and a thickness of 1 mm.

  The organic EL element 12 includes a protective layer 12a, a transparent anode layer 12b (first electrode layer), an organic material layer OL, and a cathode layer 12g (second electrode layer) in this order on the inner surface of the cylindrical tube 1. Yes. The organic layer OL has first to fourth layers 12c to 12f. The protective layer 12a, the transparent anode layer 12b, the organic layer OL, and the cathode layer 12g are arranged concentrically from the center of the cylindrical tube 1 (in the LD direction in the figure).

The protective layer 12a has a function of preventing movement of alkali metal ions. Therefore, even if a material containing alkali metal ions such as soda lime glass is used as the material of the cylindrical tube 1, the alkali metal ions are prevented from moving from the cylindrical tube 1 to the transparent anode layer 12b. The protective layer 12a is a layer having a thickness of 10 nm formed of, for example, silicon oxide (SiO ₂ ).

  The transparent anode layer 12 b has translucency and functions as an anode of the organic EL element 12. The transparent anode layer 12b is a conductive oxide layer, for example, a layer having a thickness of 5 μm formed of indium tin oxide (ITO (Tin doped Indium Oxide)).

  The first layer 12c of the organic layer OL is a layer having a thickness of 40 nm formed from, for example, an organic material (NPD) represented by the following formula (1).

The second layer 12d is made of, for example, an organic material (Znbox 2) represented by the following formula (2) as a main component and 1.5% by weight of perylene (C ₂₀ H ₁₂ ) represented by the following formula (3). It is a 7 nm thick layer that has been doped.

  The third layer 12e has, for example, an organic material (Znbox2) represented by the above formula (2) as a main component and is doped with 0.25 wt% by the organic material (DCM1) represented by the following formula (4). It was a layer with a thickness of 23 nm.

  The fourth layer 12f is a layer having a thickness of 30 nm formed from, for example, the organic material (Znbox 2) represented by the above formula (2).

  The first layer 12c has a function as a hole transport layer, and the fourth layer 12f has a function as an electron transport layer. Each of the second layer 12d and the third layer 12e has a function as a light emitting layer by containing perylene and DCM1 as dopant dyes. Blue light and orange light emission are generated in each of the second layer 12d and the third layer 12e, and white light is obtained by mixing these two colors of light.

  The cathode layer 12 g has a function as a cathode of the organic EL element 12. The cathode layer 12g is a metal layer, for example, a layer made of aluminum and having a thickness of 50 nm.

  In the present embodiment, the cathode layer 12 g is disposed on the inner peripheral side of the cylindrical tube 1, and the transparent anode layer 12 b is disposed on the outer peripheral side of the cylindrical tube 1. Further, in order to efficiently emit light to the outside of the cylindrical tube 1, the cathode layer 12g has a property of reflecting light, and the transparent anode layer 12b has a property of transmitting light. For this reason, the material of the transparent anode layer 12b and the material of the cathode layer 12g are different. As a result, the material of the transparent anode layer 12b and the material of the cathode layer 12g have different specific electric resistance values determined by the material. Therefore, in the cathode layer 12g of the present embodiment, the electrical resistance value per unit length along the extending direction of the cylindrical tube 1 is adjusted to be the same as that of the transparent anode layer 12b. In other words, the resistance values of the surfaces when the transparent anode layer 12b and the cathode layer 12g are cut along the current path are the same. For example, when the transparent anode layer 12b is made of ITO and the cathode layer 12g is made of metal, the thickness of the cathode layer 12g is thinner than the thickness of the transparent anode layer 12b.

  The material of the transparent anode layer 12b and the material of the cathode layer 12g may be the same or different.

  In addition, the cathode layer 12g is not formed in the area | region of the both ends side of the length direction of the cylindrical tube 1 among the area | regions on the organic substance layer OL. The region where the cathode layer 12g is not formed is a short prevention space SP. By providing this short prevention space SP, the cathode layer 12g and the transparent anode layer 12b are prevented from being short-circuited at the end of the organic EL element 12.

  The sealing unit 110 includes sealing components 110a and 110b and O-rings 124a and 124b. Electrodes 112a and 112b protruding toward the outside of the organic EL light emitting device 130 are disposed on the sealing components 110a and 110b, respectively. Further, desiccants 127a and 127b are disposed on the sealing components 110a and 110b, respectively. Each of the sealing parts 110a and 110b is detachably fixed to both ends of the cylindrical tube 1 by O-rings 124a and 124b. The material of the sealing part 110 is glass or aluminum, for example. Each of the O-rings 124a and 124b is made of an elastomer, and is in close contact with one of the sealing components 110a and 110b and the cylindrical tube 1 by the restoring force of the elastomer. Thereby, the sealing part 110 has sealed the inside of the cylindrical tube 1 filled with the inert gas IG. Therefore, a region where the organic EL element 12 is formed, that is, a region including the organic material layer OL and the cathode layer 12 g is hermetically sealed from the outside of the organic EL light emitting device 130. In addition, in order to make sealing by the O-rings 124a and 124b more reliable, screws for fastening the O-rings 124a and 124b may be attached to the sealing portion 110.

  FIG. 3 is a schematic diagram when viewed from the line III-III in FIG. 2 and schematically shows the connection between the transparent anode layer 12b and the wiring 113a. Referring to FIG. 3, a plurality of portions of transparent anode layer 12b and electrode 112a (first external electrode) are electrically connected. The distances from the electrode 112a to the plurality of locations of the transparent anode layer 12b are the same.

  FIG. 4 is a schematic diagram when viewed from the line IV-IV in FIG. 2, and is a diagram schematically showing the connection between the cathode layer 12g and the wiring 113b. Referring to FIG. 4, a plurality of portions of cathode layer 12g and electrode 112b (second external electrode) are electrically connected. The distances from the electrode 112b (second external electrode) to the plurality of locations of the cathode layer 12g are the same.

  The above “same distance” means that there is no variation in the electric resistance values from the electrode 112a to the plurality of locations on the transparent anode layer 12b, and the respective electric resistance values from the electrode 112b to the plurality of locations on the cathode layer 12g. There is no variation in the resistance value.

  The electrode 112a is connected at one end of the transparent anode layer 12b (the outer peripheral side of the cylindrical tube 1), and the electrode 112b is connected at the other end of the cathode layer 12g (the inner peripheral side of the cylindrical tube 1). Yes.

  In the present embodiment, one end of the wiring 113a is electrically connected to the transparent anode layer 12b radially, and the other end of the wiring 113a is electrically connected to the electrode 112a. One end of the wiring 113b is electrically connected to the cathode layer 12g in a radial manner, and the other end of the wiring 113b is electrically connected to the electrode 112b. Each of the electrodes 112a and 112b is formed so as to penetrate through the centers of the sealing components 110a and 110b. That is, since the lengths of the wirings 113a and 113b can be made the same with respect to the circumferential direction of the cylindrical tube 1, the difference in electric resistance value between the wirings 113a and 113b can be reduced. With this configuration, the difference in resistance between the wirings 113a and 113b in the circumferential direction of the cylindrical tube 1 can be reduced. Therefore, by applying a voltage between the electrode 112a and the electrode 112b exposed outside the sealing region of the cylindrical tube 1, a uniform potential difference is generated in the organic layer OL between the transparent anode layer 12b and the cathode layer 12g. Due to this potential difference, a uniform current is supplied to the organic layer OL, and uniform light emission occurs.

  Next, the organic EL light emitting device 130 of the present embodiment will be described using the equivalent circuit diagram shown in FIG. In FIG. 5, the transparent anode layer 12b and the cathode layer 12g are represented by resistors, and the organic EL element 12 is represented by a diode and a resistor. The other parts are not thin films and are represented by solid lines as having an negligible electrical resistance.

  As shown in FIG. 5, since the material of the transparent anode layer 12b and the material of the cathode layer 12g are different depending on their functions, the electrical resistivity (electric resistance value per unit volume) of the transparent anode layer 12b. And the electrical resistivity (electric resistance value per unit volume) of the cathode layer 12g are different from each other. However, by optimizing the film thickness of at least one of the transparent anode layer 12b and the cathode layer 12g, the transparent anode layer 12b and the cathode layer 12g per unit length at a position facing the cylindrical tube 1 in the extending direction. The electrical resistance can be the same. Therefore, when a current is supplied from the electrode 112a to the transparent anode layer 12b and a current is extracted from the other electrode 112b to the cathode layer 12g, the same voltage proportional to the length of the cylindrical tube 1 in the length direction of the cylindrical tube 1 is obtained. Each descent occurs. For example, when a DC voltage of 10V is applied, the voltage drops to 9V at the center of the transparent anode layer 12b and to 8V at the end due to the electrical resistance of the transparent anode layer 12b. Assuming that the voltage on the outlet side of the cathode layer 12g is 0V, a voltage of 1V is generated at the center of the cathode layer 12g and a voltage of 2V is generated at the end. That is, the potential difference applied to the organic layer OL is equal to 8 V at all positions. By injecting the current in this way, the current can flow uniformly to the light emitting layer (organic layer OL) in the longitudinal direction of the cylindrical tube 1.

  When a voltage is applied to the transparent anode layer 12b and the cathode layer 12g, electrons and holes are respectively injected. The injected electrons and holes pass through the fourth layer 12f as the electron transport layer and the first layer 12c as the hole transport layer, respectively, and the second layer 12d and the third layer as the light emitting layer, respectively. Join at 12e. As described above, in this embodiment, the voltage difference applied to the organic material layer OL is the same at all positions. Therefore, if the film thickness of the organic material layer OL is uniform, the current flowing through the organic material layer OL is cylindrical. It becomes the same at all positions in the extending direction of the tube 1. Therefore, it is possible to suppress variations in light emission luminance in the direction in which the cylindrical tube 1 extends.

  In addition, since variation in light emission luminance can be suppressed, a large-area organic material layer OL can be used without disposing a plurality of electrodes in a dispersed manner.

  Furthermore, since it is not necessary to improve the luminance of the low emission luminance area, it is not necessary to increase the amount of current in order to improve the luminance of the low emission luminance area. For this reason, Joule heat generated by the electrical resistance of the transparent anode layer 12b and the cathode layer 12g can be reduced. Therefore, the light emission efficiency of the organic EL light emitting device 130 can be improved and the lifetime can be improved.

  In the present embodiment, the organic layer OL, the transparent anode layer 12b, and the cathode layer 12g have a uniform thickness, but the present invention is not limited to this. For example, even if the film thickness of the transparent anode layer 12b is changed, the potential difference applied to the organic layer OL should be the same in all places by optimizing the film thickness of the cathode layer 12g.

  In the present embodiment, the transparent anode layer 12b is disposed on the outer peripheral side of the cathode layer 12g, but the present invention is not limited to this. The transparent anode layer 12b may be disposed on the inner peripheral side of the cathode layer 12g. In this case, one end connected to the electrode 112a in the transparent anode layer 12b is on the inner peripheral side of the cylindrical tube 1, and the other end connected to the electrode 112b in the cathode layer 12g is on the outer peripheral side of the cylindrical tube 1. Also good.

  In this embodiment, a cylindrical tube is used as the tube (base material), but the present invention is not limited to this. For example, the cross-sectional shape of the tube may be rectangular.

(Modification 1)
FIG. 17 is a cross-sectional view of an organic EL light emitting device in Modification 1 of Embodiment 1. Referring to FIG. 17, the organic EL light emitting device according to Modification 1 of Embodiment 1 has three organic EL elements 12 (light emitting elements) with a space SP for short-circuiting therebetween. The cathode layer 12g of one organic EL element 12 is connected to the transparent anode layer 12b of another adjacent organic EL element 12 by a connection wiring 114a. That is, the plurality of organic EL elements 12 are connected in series with each other. The cathode layer 12g may be extended instead of the connection wiring 114a and connected to the transparent anode layer 12b of the adjacent organic EL element 12.

  FIG. 18 is an equivalent circuit diagram of the organic EL light emitting device in Modification 1 of Embodiment 1. In FIG. 18, the transparent anode layer 12b is represented by a resistor, and the organic EL element 12 is represented by a diode and a resistor. The other parts are not thin films and are represented by solid lines as having an negligible electrical resistance.

  Referring to FIG. 18, when a current is supplied from the electrode 112 a to the transparent anode layer 12 b and a current is extracted from the other electrode 112 b to the cathode layer 12 g, the length of the cylindrical tube 1 is proportional to the length of the cylindrical tube 1. The same voltage drop occurs in each organic EL element 12. By injecting the current in this way, the current can flow uniformly to the light emitting layer (organic layer OL) in the longitudinal direction of the cylindrical tube 1.

  FIG. 19 is a conceptual diagram of an organic EL light emitting device in Modification 1 of Embodiment 1. Referring to FIG. 19A, the organic EL element 12 that emits light at a voltage of 5 V and a current of 5 A has a transparent anode of a transparent anode layer 12b in the direction in which the cylindrical tube 1 extends. The layer 12b generates about 12.5 W. Referring to FIG. 19B, when this organic EL element 12 is divided into five and connected in series, the electrical resistance of transparent anode layer 12b in the direction in which one cylindrical tube 1 extends becomes 0.1Ω. Since the area of the divided organic EL element 12 is 1/5, the current required for light emission is also 1A of 1/5, but the electric resistance from the organic layer OL to the cathode layer 12g in the direction inside the cylindrical tube 1 Will be 5 times. Therefore, one of the divided organic EL elements 12 emits light at a voltage of 5V and a current of 1A, and when connected in series, emits light at a voltage of 25V and a current of 1A. At this time, the individual transparent anode layers 12b generate heat of about 0.1 W, and even a total of five can be suppressed to heat generation of 0.5 W. That is, the heat generation amount can be reduced to 1/25 by dividing the organic EL element 12 into five.

(Modification 2)
FIG. 20 is a cross-sectional view of an organic EL light emitting device in Modification 2 of Embodiment 1. Referring to FIG. 20, organic EL element 12 in Modification 2 of Embodiment 1 includes transparent anode layer 12 b (first electrode layer), organic layer OL (organic matter) from the outer periphery to the inner periphery of cylindrical tube 1. Layer), cathode layer 12g (second electrode layer), transparent anode layer 12b (third electrode layer), organic layer OL (second organic layer), and cathode layer 12g (fourth electrode layer). Yes. The transparent anode layer 12b (first electrode layer), the organic material layer OL (organic material layer) and the cathode layer 12g (second electrode layer) form a first light emitting device (first organic EL device), and the transparent anode layer 12b (first material layer). The second light emitting element (second organic EL element) is formed by the three electrode layers), the organic layer OL (second organic layer), and the cathode layer 12g (fourth electrode layer). That is, the organic EL element 12 includes a first light emitting element and a second light emitting element. The electrical resistance value of the transparent anode layer 12b (first electrode layer) and the electrical resistance value of the cathode layer 12g (second electrode layer) are the same, and the electrical resistance value of the transparent anode layer 12b (third electrode layer). And the electrical resistance value of the cathode layer 12g (fourth electrode layer) are the same.

  A transparent material is used for the cathode layer 12g between the organic material layer OL and the transparent anode layer 12b (intermediate portion). Each organic EL element 12 is connected by wirings 113a and 113b and connection wirings 114a and 114b. When alternating current is applied to the electrodes 112a and 112b, the positive and negative polarities are alternately switched. When the electrode 112a is positive and the electrode 112b is negative, the outer organic layer OL becomes a forward voltage and a current flows to emit light. Since the inner organic layer OL has a reverse voltage, no current flows. Next, when the polarity is reversed and the electrode 112a is negative and the electrode 112b is positive, the inner organic layer OL becomes a forward voltage, and a current flows to emit light. Since the outer organic material layer OL has a reverse voltage, no current flows.

  21 and 22 are equivalent circuit diagrams of the organic EL light emitting device in Modification 2 of Embodiment 1. FIG. FIG. 21 is an equivalent circuit diagram when the electrode 112a is positive and the electrode 112b is negative, and FIG. 22 is an equivalent circuit diagram when the electrode 112a is negative and the electrode 112b is positive. 21 and 22, the transparent anode layer 12b is represented by a resistance, and the organic EL element 12 is represented by a diode and a resistance. The other parts are not thin films and are represented by solid lines as having an negligible electrical resistance.

  Referring to FIGS. 21 and 22, when alternating current is supplied to electrodes 112 a and 112 b, the same voltage drop proportional to the length of cylindrical tube 1 occurs in the length direction of cylindrical tube 1. Thus, even in the case of alternating current, a current can be made to uniformly flow through the light emitting layer (organic layer OL) in the longitudinal direction of the cylindrical tube 1.

(Modification 3)
FIG. 23 is a cross-sectional view of the configuration of the organic EL light emitting device of Modification 3 of Embodiment 1 of the present invention. The organic EL light emitting device of Modification 3 of Embodiment 1 is formed of a light-transmitting property that is formed along the extending direction of the cylindrical tube 1 inside the cylindrical tube 1 and outside the transparent anode layer 12b and can be bent. The substrate further includes: 24 and 25 are schematic diagrams showing a substrate of Modification 3 of Embodiment 1. FIG. 23 and 24, for example, a flexible substrate 115 is used as the substrate of the third modification.

  In Modification 3, a flexible substrate 115, a transparent anode layer 12b, an organic material layer OL, and a cathode layer 12g are formed in this order on the inner surface of the cylindrical tube 1. In the modification 3, since the flexible substrate 115 is formed on the inner surface of the cylindrical tube 1, the protective layer 12a is not formed. Note that a protective layer 12 a may be formed between the flexible substrate 115 and the cylindrical tube 1.

  When manufacturing the organic EL light-emitting device of the modification 3, it can carry out by the following methods, for example. First, referring to FIG. 24, a flexible substrate 115 is prepared and bent in the direction of the arrow. Thereby, the cylindrical flexible substrate 115 can be formed as shown in FIG. A flexible substrate 115 shown in FIG. 25 is inserted into the cylindrical tube 1 along the direction of the arrow shown in FIG. FIG. 26 is a schematic diagram illustrating a manufacturing process of the organic EL light emitting device of the third modification of the first embodiment. Thereafter, by forming the organic EL element 12 and the like, the organic EL light emitting device of Modification 3 shown in FIG. 23 can be manufactured.

  Here, the manufacturing method of the organic EL light emitting device of Modification 3 is not limited to the above method, and after forming the organic EL element 12 on the flexible substrate 115 shown in FIG. 24, as shown in FIG. The shape may be inserted into the cylindrical tube 1 shown in FIG.

(Modification 4)
FIG. 27 is a cross-sectional view of the configuration of the organic EL light emitting device of Modification 4 of Embodiment 1 of the present invention. FIG. 28 and FIG. 29 are schematic diagrams showing a flexible substrate and auxiliary electrodes according to the fourth modification of the first embodiment. 27 to 29, the organic EL light emitting device of Modification 4 of Embodiment 1 includes a plurality of flexible substrate 115, transparent anode layer 12b, organic material layer OL, and cathode layer 12g of Modification 3 (FIG. 27). In this case, a strip-shaped auxiliary electrode 114 is further provided which is laminated and is in contact with the cathode layer 12g. The auxiliary electrode 114 is provided to make contact inside the laminated flexible substrate 115.

  In Modification 4, the flexible substrate 115, the transparent anode layer 12b, the organic layer OL, the cathode layer 12g, the flexible substrate 115, the transparent anode layer 12b, and the organic layer OL are sequentially arranged on the inner surface of the cylindrical tube 1. The cathode layer 12g is formed. That is, a plurality of laminates including the flexible substrate 115, the transparent anode layer 12b, the organic material layer OL, and the cathode layer 12g are included, and the plurality of laminates are wound so as to overlap in a cylindrical shape. The cathode layer 12g located between the organic layer OL and the flexible substrate 115 preferably has a light-transmitting property, and indium tin oxide or the like can be used.

  In the fourth modification, the auxiliary electrode 114 connects the wirings 113a and 113b and the plurality of cathode layers 12g, respectively. The auxiliary electrode 114 may be connected to the transparent anode layer 12b instead of the cathode layer 12g.

  When manufacturing the organic EL light-emitting device of the modification 4, it can carry out, for example with the following method. First, referring to FIG. 28, it has a flexible substrate 115, auxiliary electrodes 114 formed in regions on both ends in the length direction of flexible substrate 115, and organic EL element 12 formed on flexible substrate 115. Prepare a laminate. Thereafter, this laminate is bent in the direction of the arrow shown in FIG. Thereby, a laminated body can be formed in a cylindrical shape as shown in FIG. A cylindrical flexible substrate 115 shown in FIG. 29 or the like is inserted into the cylindrical tube 1 along the direction of the arrow shown in FIG. Can do.

(Modification 5)
30 and 31 are schematic views showing a metal electrode of Modification 5 of Embodiment 1 of the present invention. As shown in FIGS. 30 and 31, the organic EL light emitting device of Modification 5 is connected to the transparent anode layer 12b that is the first electrode layer, and has a straight or wire mesh shape for reducing the electric resistance of the transparent anode layer 12b. The metal electrode 12i is further provided. The metal electrode 12i may be a straight line, that is, a stripe shape as shown in FIG. 30, or may be a wire mesh shape, that is, a mesh shape, as shown in FIG. 30 and 31, the metal electrode 12i is formed on the outer periphery of the transparent anode layer 12b, but may be formed on the inner periphery.

  Since the transparent anode layer 12b has translucency, the electric resistance is larger than that of a normal metal. For this reason, electrical resistance can be reduced by providing the linear or metal-mesh-like metal electrode 12i in the outer side or inner side of the transparent anode layer 12b.

(Embodiment 2)
First, the configuration of the organic EL light emitting device of the present embodiment will be described with reference to FIG. FIG. 6 is a schematic cross-sectional view of an organic EL light-emitting device according to Embodiment 2 of the present invention. Referring to FIG. 6, in organic EL light emitting device 130 of the present embodiment, it is positioned between organic layer OL and cathode layer 12g in the first embodiment, and is disposed along the direction in which cylindrical tube 1 extends. Further, a lead electrode 112c is further provided.

Referring to FIG. 6, the electrode 112b extends along the direction in which the cylindrical tube 1 extends and faces the organic layer OL. A cathode layer 12g is formed inside the cylindrical tube 1 of the electrode 112b and on a region facing the organic layer OL. The cathode layer 12g is provided at a position spatially separated from the organic material layer OL. The electrode 112b in the region where the cathode layer 12g is formed and the cathode layer 12g constitute a cathode 12h. For the cathode layer 12g, for example, an electron emission source such as a carbon nanotube or a silicon nanocrystal layer can be used.

  A space between the organic material layer OL and the cathode 12h is a vacuum VS. In the present embodiment, the inside of the cylindrical tube 1 is kept at a vacuum VS.

  The lead electrode 112c is disposed between the cathode layer 12g and the organic layer OL. The extraction electrode 112c can perform functions such as rectification, oscillation, modulation, detection, and amplification by being controlled by an electric field or a magnetic field when electrons emitted from the cathode layer 12g are injected into the organic layer OL. It is configured as follows. As such an extraction electrode 112c, for example, a mesh-like metal member can be used.

  Next, the organic EL light emitting device 130 of the present embodiment will be described with reference to an equivalent circuit diagram shown in FIG. In FIG. 7, the transparent anode layer 12b is represented by a resistor, and the organic EL element 12 is represented by a diode and a resistor. The other parts are not thin films and are represented by solid lines as having an negligible electrical resistance.

  Referring to FIG. 7, when a voltage is applied to extraction electrode 112c, electrons e are emitted from cathode layer 12g formed on the surface of cathode 12h. The emitted electrons e pass between the extraction electrodes 112c and are injected into the organic layer OL. For this reason, a current is injected into the organic EL element 12.

  Note that, since a high voltage is applied to the extraction electrode 112c and electrons e are emitted from the cathode 12h, the emission of the electrons e is not affected by the resistance of the transparent anode layer 12b.

  According to the organic EL light emitting device 130 in the present embodiment, the organic EL light emitting device 130 is further provided with a lead electrode 112c located between the organic material layer OL and the cathode layer 12g and disposed along the direction in which the cylindrical tube 1 extends. For this reason, the electrons e travel straight from the cathode layer 12g to the organic layer OL through the extraction electrode 112c, whereby a uniform current can be injected into the organic layer OL. Therefore, variation in the light emission luminance of the organic EL light emitting device 130 can be further suppressed.

In the present embodiment, since electrons e can be efficiently injected into the organic layer OL, for example, light emission is performed with a high current efficiency such as a current density of 0.14 mA / cm ² or more and a light emission efficiency of 138 cd / A or more. Can be made.

  Furthermore, unlike Embodiment 1, in this Embodiment, the area | region of vacuum VS is formed between the cathode 12h and the organic substance layer OL. For this reason, it is possible to suppress a short circuit due to a point defect generated in the organic material layer OL.

  In the organic EL light emitting device 130, carbon nanotubes are preferably used for the cathode layer 12g. When the applied voltage of the carbon nanotube reaches the threshold voltage, automatic electron emission occurs as a whole due to the self-emission phenomenon. For this reason, since more uniform electron injection is obtained, the dispersion | variation in light emission luminance can be suppressed more.

  In the organic EL light emitting device 130, preferably, a silicon nanocrystal layer is used for the cathode layer 12g. When the applied voltage of the silicon nanocrystal layer reaches the threshold voltage, automatic electron emission occurs entirely due to the ballistic electron emission phenomenon. For this reason, since more uniform electron injection is obtained, the dispersion | variation in light emission luminance can be suppressed more.

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

(Embodiment 3)
First, the configuration of the organic EL lighting device according to the present embodiment will be described. FIG. 8 is a side view schematically showing the configuration of the organic EL lighting device according to Embodiment 3 of the present invention, and FIG. 9 is a top view. The organic EL lighting device of the present embodiment includes a plurality of organic EL light emitting devices 130 and a coupler 131 that connects the organic EL light emitting devices 130.

  8 and 9, in the organic EL lighting device of the present embodiment, electrodes 112a and 112b (see FIGS. 2 and 6) at both ends of four cylindrical organic EL light emitting devices 130 are connected. It is fixed with 131. The couplers 131 disposed at both ends are coupled by a reflecting mirror 132, and each organic EL light emitting device 130 has a structure that can be easily removed.

  Since the electrodes 112a and 112b have positive and negative polarities, the electrodes 112a and 112b have different shapes and are coupled to the coupler 131, respectively.

  10 and 11 are equivalent circuit diagrams of the organic EL lighting device according to Embodiment 3 of the present invention. With reference to FIGS. 10 and 11, each organic EL light emitting device 130 is represented by a diode and a resistor. Since the other parts are metal wiring, the electric resistance is negligible and is indicated by a solid line.

  In the organic EL lighting device, four organic EL light emitting devices 130 are connected in series in the coupler 131 as shown in FIG. 10 or in parallel as shown in FIG.

(Modification 1)
FIG. 12 is an external view schematically showing a configuration of an organic EL lighting device in Modification 1 of Embodiment 3. As shown in FIG. 12, four organic EL light emitting devices 130 are connected using four couplers 131 so that the planar shape is a square.

(Modification 2)
FIG. 13 is an external view schematically showing a configuration of an organic EL lighting device in Modification 2 of Embodiment 3. As shown in FIG. 13, six organic EL light emitting devices 130 are connected using six couplers 131 so that the planar shape is a hexagon.

(Modification 3)
FIG. 14 is an external view schematically showing a configuration of an organic EL lighting device in Modification 3 of Embodiment 3. As shown in FIG. 14, eight organic EL light emitting devices 130 are connected using eight couplers 131 so that the planar shape is an octagon.

(Modification 4)
FIG. 15 is an external view schematically showing a configuration of an organic EL lighting device in Modification 4 of Embodiment 3. As shown in FIG. 15, three organic EL light emitting devices 130 are connected using two couplers 131 so as to form a straight line.

(Modification 5)
FIG. 16 is an external view schematically showing a configuration of an organic EL lighting device in Modification 5 of Embodiment 3. As shown in FIG. 16, the coupler 131 in the present modification connects six organic EL light emitting devices 130. For this reason, the coupler 131 connects the six organic EL light emitting devices 130 radially.

  According to the organic EL lighting device of the present embodiment and the modification thereof, the plurality of organic EL light emitting devices 130 and the coupler 131 that connects the plurality of organic EL light emitting devices 130 are provided. A plurality of organic EL light emitting devices 130 are connected in series or in parallel by a coupler 131 to form a set of organic EL lighting devices. For this reason, an organic EL lighting device having an arbitrary shape can be realized.

  In the organic EL lighting device, the coupler 131 is preferably detachable from the organic EL light emitting device 130. For this reason, the organic EL light-emitting device 130 can be removed as needed, such as exchanging some of the plurality of organic EL light-emitting devices 130. Therefore, convenience can be improved.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can realize an organic EL light emitting device capable of suppressing variations in light emission luminance, and thus can be applied to an organic EL light emitting device that is required to emit light uniformly over a large area, particularly an organic EL lighting device.

  DESCRIPTION OF SYMBOLS 1 Cylindrical tube, 12 Organic EL element, 12a Protective layer, 12b Transparent anode layer, 12c 1st layer, 12d 2nd layer, 12e 3rd layer, 12f 4th layer, 12g Cathode layer, 12h Cathode, 12i Metal electrode, 110 sealing portion, 110a, 110b sealing component, 112a, 112b electrode, 112c lead electrode, 113a, 113b wiring, 114 auxiliary electrode, 114a, 114b connection wiring, 115 flexible substrate, 124a, 124b O-ring, 127a 127b, desiccant, 130 organic EL light emitting device, 131 coupler, 132 reflector, OL organic layer, SP short prevention space, IG inert gas, VS vacuum, e electron.

Claims (1)

A translucent tube;
A first electrode layer formed inside the tube along the direction in which the tube extends and having translucency;
An organic material layer that is formed inside the first electrode layer along a direction in which the tube extends and emits light when a voltage is applied;
A second electrode layer formed along the direction in which the tube extends inside the organic layer,
Either one of the first electrode layer and the second electrode layer is an anode, the other is a cathode,
Ri same Der the electrical resistance of the second electrode layer and the electric resistance value of the first electrode layer,
A first external electrode electrically connected to the first electrode layer;
A second external electrode electrically connected to the second electrode layer;
A plurality of first wirings connecting the plurality of locations of the first electrode layer and the first external electrode;
A plurality of second wires connecting the plurality of locations of the second electrode layer and the second external electrode;
The plurality of first wirings are respectively connected radially to the plurality of locations of the first electrode layer around the first external electrode,
The plurality of second wirings are respectively connected radially to the plurality of locations of the second electrode layer around the second external electrode,
Each distance from the first external electrode to the plurality of locations of the first electrode layer is the same,
The organic EL light emitting device, wherein each distance from the second external electrode to the plurality of locations of the second electrode layer is the same .

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