JP2008103359A - Organic electroluminescent display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent display which can achieve the reduction of the electromagnetic waves of unwanted radiation at a low cost. <P>SOLUTION: A display panel 20 is such that a substrate on which an organic electroluminescent device is formed and a sealing substrate are arranged facing each other, and laminated across the entire surfaces via an adhesive resin. The organic electroluminescent device has a structure in which a first electrode, an organic layer of at least one layer containing a light emission layer, and a second electrode are laminated in order; and light is extracted from the second electrode side, i.e. a light emission surface 20A. A rear surface layer 32A constituted by containing a conductive material is adhered through an adhesive layer 33 so as to cover the surface of the substrate side where the organic electroluminescent device is not installed, i.e. the rear surface 20B of the display panel 20. The rear surface layer 32A is preferably of a film containing graphite. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a self-luminous display device using a self-luminous element, and more particularly, to a plurality of organic electroluminescent elements in which a first electrode, one or more organic layers including a light-emitting layer, and a second electrode are sequentially laminated ( The present invention relates to a self-luminous display device having an organic EL (Electroluminescence) element and taking out light generated in a light emitting layer from a second electrode side.

  Conventionally, display devices (displays) using self-luminous elements such as light emitting diodes (LEDs), laser diodes (LD), and organic electroluminescent elements have been developed. In this type of display device, generally, a plurality of self-luminous elements are arranged in a matrix to form a screen portion (display panel), and each element is selectively made to emit light according to a video signal, thereby displaying a video. Done.

A display device using a self-luminous element is a liquid crystal display (LCD).
Compared with non-self-luminous display devices such as Display), there is an advantage that a backlight is unnecessary. In particular, a display device (organic EL display) using an organic electroluminescent element has been attracting attention in recent years because it has a wide viewing angle, high visibility, and a high response speed of the element.

  As an organic electroluminescent element, for example, a device in which a first electrode, an organic layer including a light emitting layer, and a second electrode are sequentially laminated on a substrate is known. In such an organic electroluminescent element, the light generated in the light emitting layer may be extracted from the substrate side depending on the type of display, but may be extracted from the second electrode side.

  As a drive control method of the organic electroluminescence element, there are a simple matrix method (passive matrix method) and an active matrix method. In the simple matrix method, a plurality of data lines extending in the vertical direction and a plurality of scanning lines extending in the horizontal direction are formed in a matrix, and each scanning line is sequentially scanned and a signal is supplied to the data lines within one frame period. The organic EL element located at the intersection of the scanning line and the data line is caused to emit light. In the active matrix system, an active element (active element) such as a TFT (Thin Film Transister) is connected to each organic electroluminescent element, and light emission control is performed for each organic electroluminescent element.

  In recent years, an active matrix drive control is being adopted in an organic EL display as well as a liquid crystal display. In an active matrix organic EL display, it is possible to use an organic electroluminescent element having a structure for extracting light from the substrate side, but an organic electroluminescent element having a structure for extracting light from the second electrode side is more advantageous. is there. This is because the amount of light is not affected by the arrangement of TFTs formed on the substrate, so that the aperture ratio is improved, and high brightness and high definition are possible.

  By the way, generally electromagnetic waves leaking from electronic devices such as computers may cause malfunction of other electronic devices in the vicinity, and there is a concern about the influence on the human body. In particular, flat panel displays such as organic EL displays, liquid crystal displays, and plasma displays (PDPs) are generally digitally controlled, and control clocks and signals become faster with higher definition, so they are unnecessary. Countermeasures against disturbances caused by electromagnetic waves such as radiation are always necessary.

  Examples of the material having a function of shielding electromagnetic waves include metal foil, metal fiber or metal powder, and carbon fiber made of a metal having high electrical conductivity. For example, in a general electronic device, conventionally, leakage of electromagnetic waves has been performed by mixing metal fibers or carbon fibers into an insulating resin case or using a conductive resin case. However, in the case of a flat panel display, an electromagnetic wave shielding film must be provided on the front surface of the display panel. Therefore, such an electromagnetic wave shielding film material is required to have not only an electromagnetic wave shielding performance but also a transparency to visible light. The

  Therefore, conventionally, a transparent conductive material has often been used for the electromagnetic wave shielding film provided on the front surface of the display panel of the flat panel display. For example, regarding a plasma display, an example in which a transparent conductive film formed by laminating three layers of tin oxide, silver and tin oxide is provided on a transparent polymer film (Japanese Patent Laid-Open No. 10-21668), or a thin transparent acrylic plate An example in which a transparent conductive film or conductive mesh made of ITO (Indium Tin Oxide) or the like is provided (Japanese Patent Laid-Open No. 11-352897) has been proposed.

  As an example using a metal, there is an example in which a metal thin film is laminated on one side of a substrate and further subjected to chemical mechanical polishing (CMP) method to reduce the film thickness and impart visible light translucency (Japanese Patent Application Laid-Open (JP-A)). 2000-59081).

  However, such an electromagnetic wave absorption filter is relatively expensive because of the cost of processing the conductive thin film, and has been an obstacle to cost reduction.

  In particular, an organic EL display generates heat due to its efficiency when emitting light with high luminance. In addition, a glass substrate having a low thermal conductivity is often used as the substrate, and depending on the light emission state, there is a concern that a large difference occurs in the heat distribution inside the display, which adversely affects the light emission characteristics of the display.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a self-luminous display device capable of reducing electromagnetic waves such as unnecessary radiation at a low cost.

  Another object of the present invention is to provide a self-luminous display device capable of uniforming the heat distribution inside the display and enhancing the light emission characteristics.

  A self-luminous display device according to the present invention includes a display panel having a pixel circuit including a plurality of self-luminous elements on a substrate and having a peripheral control circuit around the pixel circuit, and a conductive material. And a back layer provided so as to cover at least the surface opposite to the self-light-emitting element. The back layer is configured to include at least one selected from the group consisting of simple substances, alloys, and compounds of copper (Cu), aluminum (Al), zinc (Zn), iron (Fe), and tin (Sn). It is preferable. The back layer is, for example, a thin plate member made of a conductive material, a film containing the conductive material, or a metal layer formed by at least one of plating, vapor deposition, and chemical vapor deposition It can be. As a self-luminous element, an organic electroluminescent element in which a first electrode, one or more organic layers including a light emitting layer, and a second electrode are sequentially laminated on a substrate, and light generated in the light emitting layer is extracted from the second electrode side. Is preferred.

  In the self-luminous display device according to the present invention, since the back layer configured to include a conductive material is provided so as to cover at least the surface of the display panel opposite to the self-luminous element, the back layer is provided. As a result, the control circuit and wiring electrodes for driving the self-luminous element are shielded, and electromagnetic waves such as unnecessary radiation are reduced. In addition, since the heat conduction of the display panel can be enhanced by the back layer, heat generated by light emission of a self-luminous element such as an organic electroluminescent element is dissipated and the temperature distribution inside the display panel is made uniform. Furthermore, it is useful for reinforcing the display panel.

  As described above, according to the self-luminous display device according to any one of claims 1 to 11, the conductive layer is provided so as to cover at least the surface opposite to the self-luminous element of the display panel. Since the back layer composed of the material is provided, the back layer shields the peripheral control circuit and the wiring electrode, and can prevent leakage of electromagnetic waves such as unnecessary radiation at low cost.

  In particular, according to the self-luminous display device according to claim 2, the back layer is configured to include at least one selected from the group consisting of simple substances, alloys and compounds of copper, aluminum, zinc, iron and tin. Therefore, a high electromagnetic wave shielding ability can be expected with an inexpensive material without using a transparent conductive material. Since the back layer is located on the back surface of the display panel rather than the light emitting surface, it is not necessary to use a transparent conductive material that is expensive and laborious to manufacture as in the prior art, and the materials listed in the above group are sufficient. In addition, since the heat conduction of the display panel can be enhanced by the back layer, the heat generated with the light emission of the self-luminous element is dissipated and the temperature distribution inside the display panel is made uniform. In particular, if the back layer is composed of at least one of a single element, alloy and compound of copper having a high thermal conductivity, a synergistic effect between the electromagnetic shielding effect and the heat dissipation effect can be obtained.

  In particular, according to the self-luminous display device of the third aspect, since the back layer is a thin plate member, in addition to the electromagnetic wave shielding effect described above, it is useful for reinforcing the display panel. Particularly suitable materials for the back layer for reinforcing the display panel include iron simple substance, alloy and compound. Further, by using a thin plate-like member, it can be easily manufactured or obtained, and can be easily attached with a general adhesive.

  In particular, according to the self-luminous display device according to claim 4 or 5, since the back layer is a film containing a conductive material, specifically, a film containing a ferrite-based material or graphite, High electromagnetic shielding ability can be expected. In particular, in the case of a film containing graphite, the temperature inside the display panel can be made uniform by a heat dissipation effect in addition to the electromagnetic wave shielding effect. Moreover, such a film can be easily manufactured or obtained, and can be easily attached with a general adhesive.

  Furthermore, according to the self-luminous display device according to claim 6 or 7, since the back layer is a metal layer formed on the surface opposite to the self-luminous element of the display panel, the weight of the display panel , The wiring electrode and the peripheral control circuit can be shielded and the leakage of electromagnetic waves such as unnecessary radiation can be prevented with little influence on the appearance and dimensions.

  In particular, according to the self-luminous display device according to any one of claims 9 to 11, the self-luminous element includes one or more organic layers including a first electrode and a light-emitting layer on a substrate, and Since the organic EL device is an organic electroluminescent device in which the second electrode is sequentially stacked and the light generated in the light emitting layer is extracted from the second electrode side, the organic EL device has a high brightness with the effect of preventing leakage of electromagnetic waves by the back layer. The effect of dissipating the heat generated when light is emitted at is obtained. Therefore, the temperature distribution in the display panel is made uniform, and an organic EL display having high display characteristics can be realized.

  Furthermore, according to the self-luminous display device according to claim 10 or 11, since the semi-transmissive electrode and the first electrode constitute a resonance part of the resonator, the light generated in the light emitting layer is By causing multiple interference and acting as a kind of narrow band filter, the half width of the spectrum of the extracted light can be reduced and the color purity can be improved. In addition, external light incident from the sealing panel can also be attenuated by multiple interference, and the reflectance of external light in the organic electroluminescent element can be extremely reduced by combining with a color filter. Therefore, the contrast can be further improved.

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

[First Embodiment]
FIG. 1 shows a cross-sectional structure of a self-luminous display device according to a first embodiment of the present invention. This self-luminous display device includes, for example, a self-luminous display panel 20, and an image or the like is displayed on the light emitting surface 20 </ b> A on the front surface of the display panel 20.

  FIG. 2 is a plan view of the display panel 20 as viewed from the light emitting surface 20A side. The display panel 20 is configured using a self-luminous element, for example, an organic electroluminescent element. The display panel 20 is driven by an active matrix method, and has a configuration in which a plurality of organic electroluminescent elements 22 are arranged in a display region 21B excluding a peripheral portion 21A of a substrate 21 made of an insulating material such as glass. Have.

  In the display area 21 </ b> B of the substrate 21, TFTs, capacitors, etc. (not shown) connected to the organic electroluminescent elements 22 and wiring electrodes 23 made of aluminum (Al) or the like disposed between the organic electroluminescent elements 22 are provided. A provided pixel circuit 24 is provided. In addition, a peripheral control circuit 25 for controlling a TFT and the like (not shown) of the pixel circuit 24 is disposed on the peripheral portion 21A of the substrate 21, and an external connection interface 26 is provided.

  Returning to FIG. 1 again, the display panel 20 is held from the peripheral edge to the side of the light emitting surface 20A by a frame-like holding member 31 made of metal such as aluminum, iron, or an alloy thereof, and for external connection. It is connected to the interface 26. The back surface 20 </ b> B of the display panel 20 includes a conductive material having a function of shielding electromagnetic waves in order to prevent leakage of electromagnetic waves such as unnecessary radiation generated in the pixel circuit 24 and the peripheral control circuit 25. 32A is provided. The back surface layer 32A is set to the ground potential G together with the holding member 31 and the external connection interface 26, whereby the electromagnetic wave shielding effect of the back layer 32A can be further improved.

  The back layer 32A is made of, for example, copper. In addition, the back layer 32A may be a simple substance of aluminum, zinc, iron and tin, or an alloy or compound thereof. In the present embodiment, the back layer 32A is a thin plate member, and the back layer 32A and the display panel 20 are bonded to each other with an adhesive 33. The holding member 31 has a U-shaped cross-section, and the back layer 32A and the holding member 31 are directly connected. The adhesive 33 is intended to set the back surface layer 32A to the ground potential G together with the holding member 31 and the external connection interface 26. Therefore, the material of the adhesive 33 is not particularly limited. An adhesive can be used.

  FIG. 3 shows a cross section in the display area 21 </ b> B of the display panel 20. In the display panel 20, the substrate 21 on which the organic electroluminescent element 22 is formed and the sealing substrate 27 are disposed to face each other, and are bonded together with an adhesive resin 28 made of, for example, an ultraviolet curable resin or a thermosetting resin. . On the substrate 21, an organic electroluminescent element 22R that generates red light, an organic electroluminescent element 22G that generates green light, and an organic electroluminescent element 22B that generates blue light are sequentially arranged as a whole. It is provided in a matrix. In FIG. 3, the wiring electrode 23 disposed between the organic electroluminescent elements 22R, 22G, and 22B is omitted.

  The organic electroluminescent elements 22R, 22G, and 22B have, for example, a structure in which an anode 12 as a first electrode, an insulating layer 13, an organic layer 14, and a cathode 15 as a second electrode are stacked in this order from the substrate 21 side. have. The organic electroluminescent elements 22R, 22G, and 22B are covered with a protective layer (passivation) 16 made of, for example, silicon nitride (SiN). The protective layer 16 is for preventing moisture and oxygen from entering the organic electroluminescent elements 22R, 22G, and 22B.

  The anode 12 has, for example, a thickness in the stacking direction (hereinafter simply referred to as thickness) of about 200 nm and is made of platinum (Pt), gold (Au), silver (Ag), chromium (Cr), tungsten (W), or the like. It is comprised with the metal or its alloy.

The insulating layer 13 is for ensuring the insulation between the anode 12 and the cathode 15 and for accurately setting the shape of the light emitting region in the organic electroluminescent elements 22R, 22G, and 22B to a desired shape. The insulating layer 13 has a thickness of, for example, about 600 nm, is made of an insulating material such as silicon dioxide (SiO ₂ ), and has an opening 13A corresponding to the light emitting region.

  The organic layer 14 has a different configuration for each of the organic electroluminescent elements 22R, 22G, and 22B. FIG. 4 shows an enlarged configuration of the organic layer 14 in the organic electroluminescent elements 22R and 22G. In the organic electroluminescent elements 22R and 22G, the organic layer 14 has a structure in which a hole injection layer 14A, a hole transport layer 14B, and a light emitting layer 14C made of an organic material are stacked in this order from the anode 12 side. Yes. The hole injection layer 14A and the hole transport layer 14B are for increasing the efficiency of hole injection into the light emitting layer 14C. The light emitting layer 14 </ b> C generates light by current injection, and emits light in a region corresponding to the opening 13 </ b> A of the insulating layer 13.

  In the organic electroluminescent element 22R, the hole injection layer 14A has, for example, a thickness of about 30 nm and is made of 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine (MTDATA). The hole transport layer 14B has a thickness of, for example, about 30 nm and is composed of bis [(N-naphthyl) -N-phenyl] benzidine (α-NPD). Is about 40 nm, and is composed of 8-quinolinol aluminum complex (Alq) mixed with 2% by volume of 4-dicyanomethylene-6- (p-dimethylaminostyryl) -2-methyl-4H-pyran (DCM). Yes.

  In the organic electroluminescent element 22G, the hole injection layer 14A and the hole transport layer 14B are made of the same material as that of the organic electroluminescent element 22R, and the thickness of the hole transport layer 14A is about 30 nm, for example. The thickness of the hole transport layer 14B is, for example, about 20 nm. The light emitting layer 14C has, for example, a thickness of about 50 nm and is made of an 8-quinolinol aluminum complex (Alq).

  FIG. 5 shows an enlarged configuration of the organic layer 14 in the organic electroluminescent element 22B. In the organic electroluminescent element 22B, the organic layer 14 has a structure in which a hole injection layer 14A, a hole transport layer 14B, a light emitting layer 14C, and an electron transport layer 14D made of an organic material are stacked in this order from the anode 12 side. Have. The electron transport layer 14D is for increasing the efficiency of electron injection into the light emitting layer 14C.

  In the organic electroluminescent element 22B, the hole injection layer 14A and the hole transport layer 14B are made of the same material as the organic electroluminescent elements 22R and 22G, and the thickness of the hole transport layer 14A is, for example, about 30 nm. The thickness of the hole transport layer 14B is, for example, about 30 nm. For example, the light emitting layer 14C has a thickness of about 15 nm and is made of bathocuproine (BCP). For example, the electron transport layer 14D has a thickness of about 30 nm and is made of Alq.

  As shown in FIG. 4 and FIG. 5, the cathode 15 has translucency for the light generated in the light emitting layer 14C and the semitransparent electrode 15A that is semitransparent to the light generated in the light emitting layer 14C. The transparent electrode 15B has a structure in which the organic layer 14 is laminated in this order from the organic layer 14 side. As a result, in the display panel 20, light generated in the light emitting layer 14C is extracted from the cathode 15 side, as indicated by broken arrows in FIGS.

  The semi-transmissive electrode 15A has a thickness of about 10 nm, for example, and is made of an alloy (MgAg alloy) of magnesium (Mg) and silver. The semi-transmissive electrode 15A is for reflecting the light generated in the light emitting layer 14C with the anode 12. That is, the translucent electrode 15A and the anode 12 constitute a resonance part of a resonator that resonates light generated in the light emitting layer 14C. If the resonator is configured in this manner, the light generated in the light emitting layer 14C causes multiple interference, and acts as a kind of narrow band filter, thereby reducing the half-value width of the spectrum of the extracted light. Since purity can be improved, it is preferable. Further, external light incident from the sealing substrate 27 can also be attenuated by multiple interference, and an organic electroluminescent element 22R can be combined with a red filter 29R, a green filter 29G, and a blue filter 29B (see FIG. 3) described later. , 22G and 22B are preferable because the reflectance of outside light can be extremely reduced.

  For this purpose, it is preferable to match the peak wavelength of the narrow band filter with the peak wavelength of the spectrum of light to be extracted. That is, the phase shift of the reflected light generated at the anode 12 and the semi-transmissive electrode 15A is Φ (rad), the optical distance between the anode 12 and the semi-transmissive electrode 15A is L, and the light to be extracted from the cathode 15 side. When the peak wavelength of the spectrum is λ, it is preferable that the optical distance L satisfies the formula 2. In practice, it is preferable to select the optical distance L to be a positive minimum value that satisfies the formula 2. In Equation 2, L and λ may have the same unit, but for example, (nm) is the unit.

(Equation 2)
2L / λ + Φ / 2π = q (q is an integer)

  The transparent electrode 15B is for lowering the electric resistance of the semi-transmissive electrode 15A, and is made of a conductive material having sufficient translucency with respect to the light generated in the light emitting layer 14C. As a material constituting the transparent electrode 15B, for example, a compound containing indium, zinc (Zn), and oxygen is preferable. This is because good conductivity can be obtained even if the film is formed at room temperature. The thickness of the transparent electrode 15B is preferably about 200 nm, for example.

  As shown in FIG. 3, the sealing substrate 27 is located on the organic electroluminescent elements 22R, 22G, and 22B side of the substrate 21, and seals the organic electroluminescent elements 22R, 22G, and 22B together with the adhesive resin 28. It has stopped. The sealing substrate 27 is made of a material such as glass that is transparent to the light generated by the organic electroluminescent elements 22R, 22G, and 22B. The sealing substrate 27 is provided with, for example, a red filter 29R, a green filter 29G, a blue filter 29B, and a black matrix 30 as color filters, and extracts light generated in the organic electroluminescent elements 22R, 22G, and 22B. The external light reflected by the organic electroluminescent elements 22R, 22G, and 22B and the wiring electrode 23 (see FIG. 2) positioned therebetween is absorbed to improve the contrast.

  The red filter 29R, the green filter 29G, the blue filter 29B, and the black matrix 30 may be provided on either side of the sealing substrate 27, but are provided on the organic electroluminescent elements 22R, 22G, and 22B side. It is preferable. This is because the red filter 29R, the green filter 29G, the blue filter 29B, and the black matrix 30 are not exposed on the surface and can be protected by the adhesive resin 28.

  The red filter 29R, the green filter 29G, and the blue filter 29 are sequentially arranged corresponding to the organic electroluminescent elements 22R, 22G, and 22B. As a plane arrangement method of the red filter 29R, the green filter 29G, and the blue filter 29B, any of conventional arrangement methods such as a delta arrangement and a stripe arrangement may be used. Each of the red filter 29R, the green filter 29G, and the blue filter 29B is composed of a resin mixed with a pigment. By selecting the pigment, the light transmittance in the target red, green, or blue wavelength range is high. The light transmittance in the wavelength region is adjusted to be low.

As shown in FIG. 3, the black matrix 30 is provided along the boundary of the red filter 29R, the green filter 29G, and the blue filter 29B. The black matrix 30 is composed of, for example, a black resin film having an optical density of 1 or more mixed with a black colorant, or a thin film filter using thin film interference. Of these, a black resin film is preferable because it can be formed inexpensively and easily. The thin film filter is formed by, for example, laminating one or more thin films made of metal, metal nitride, or metal oxide, and attenuating light using interference of the thin film. Specific examples of the thin film filter include those in which chromium and chromium oxide (III) (Cr ₂ O ₃ ) are alternately laminated.

  As shown in FIG. 3, the adhesive resin 28 covers the entire surface of the substrate 21 on the side where the organic electroluminescent elements 22R, 22G, and 22B are provided, thereby corroding and damaging the organic electroluminescent elements 22R, 22G, and 22B. Is more effectively prevented. However, the adhesive resin 28 does not necessarily need to be provided on the entire surface of the substrate 21, and may be provided so as to cover at least the organic electroluminescent elements 22R, 22G, and 22B.

  This display device can be manufactured, for example, as follows.

  6 to 8 show the manufacturing method of this display device in the order of steps. First, as shown in FIG. 6A, for example, the black matrix 30 made of the above-described material is formed on the sealing substrate 27 made of the above-described material, and is patterned. Next, as shown in FIG. 6B, the material of the red filter 29R is applied onto the sealing substrate 27 by spin coating or the like, and patterned and baked by a photolithography technique to form the red filter 29R. Form. At the time of patterning, it is preferable that the peripheral edge of the red filter 29 </ b> R covers the black matrix 30. This is because it is difficult to perform patterning with high accuracy so as not to cover the black matrix 30, and the portion overlapping the black matrix 30 does not affect the image display. Subsequently, as shown in FIG. 6C, the blue filter 29B and the green filter 29G are sequentially formed in the same manner as the red filter 29R.

  Further, as shown in FIG. 7A, the anode 12 made of the above-described material is formed on the substrate 21 made of the above-mentioned material, for example, by direct current sputtering. Next, the insulating layer 13 is formed on the anode 12 with the above-described thickness by, for example, a CVD (Chemical Vapor Deposition) method, and a portion corresponding to the light emitting region is selectively selected using, for example, a lithography technique. Then, an opening 13A is formed.

  Subsequently, as shown in FIG. 7B, by using an area mask (not shown), for example, by vapor deposition, the hole injection layer 14A made of the above-described thickness and material corresponding to the opening 13A of the insulating layer 13 is formed. A hole transport layer 14B, a light emitting layer 14C, and an electron transport layer 14D are sequentially formed. At that time, the area mask used by the organic electroluminescent elements 22R, 22G, and 22B is changed, and film formation is performed for each of the organic electroluminescent elements 22R, 22G, and 22B. In addition, since it is difficult to deposit only the opening 13A with high accuracy, it is preferable to form the film so as to cover the entire opening 13A and slightly cover the edge of the insulating layer 13. After the organic layer 14 is formed, the translucent electrode 15A made of the above-described thickness and material is formed using an area mask (not shown) by, for example, vapor deposition. After that, the transparent electrode 15B is formed on the semi-transmissive electrode 15A by DC sputtering, for example, using the same area mask as the semi-transmissive electrode 15A. Finally, the organic electroluminescent elements 22R, 22G, and 22B are covered with the protective layer 16 made of, for example, the material described above. In addition to the formation of the organic electroluminescent elements 22R, 22G, and 22B described above, a TFT (not shown) for driving and controlling the wiring electrode 23, the peripheral control circuit 25, and the organic electroluminescent elements 22R, 22G, and 22B on the substrate 21. And capacitors are also formed.

  Thereafter, as shown in FIG. 8A, an adhesive resin 28 is applied and formed on the side of the substrate 21 where the organic electroluminescent elements 22R, 22G, and 22B are formed. The application may be performed, for example, by discharging resin from a slit nozzle type dispenser, or may be performed by roll coating or screen printing.

  Next, as illustrated in FIG. 8B, the substrate 21 and the sealing substrate 27 are bonded to each other with an adhesive resin 28 interposed therebetween. At this time, it is preferable that the surface of the sealing substrate 27 on which the red filter 29R, the green filter 29G, the blue filter 29B, and the black matrix 30 are formed is disposed so as to face the substrate 21. In addition, it is preferable that bubbles or the like are not mixed in the adhesive resin 28. Subsequently, before the adhesive resin 28 is cured, the relative positions of the sealing substrate 27 and the substrate 21 are aligned by appropriately moving the sealing substrate 27, for example. That is, the positions of the organic electroluminescent elements 22R, 22G, and 22B are aligned with the red filter 29R, the green filter 29G, and the blue filter 29B. At this time, the adhesive resin 28 is still uncured, and the relative position between the sealing substrate 27 and the substrate 21 can be moved by several hundred μm.

  Furthermore, the adhesive resin 28 is cured by irradiating ultraviolet rays or heating to a predetermined temperature, and the substrate 21 and the sealing substrate 27 are bonded. Thus, the display panel 20 shown in FIGS. 2 to 5 is completed. Finally, as shown in FIG. 1, the holding member 31 is attached to the display panel 20, and then the back layer 32 </ b> A is bonded to the back surface 20 </ b> B and the holding member 31 of the display panel 20 via the adhesive layer 33. Thus, the self-luminous display device shown in FIG. 1 is completed.

  In the self-luminous display device thus manufactured, when a predetermined voltage is applied between the anode 12 and the cathode 15, a current is injected into the light emitting layer 14C, and holes and electrons are recombined. As a result, light emission occurs mainly at the interface on the light emitting layer 14C side. This light is multiple-reflected between the anode 12 and the semi-transmissive electrode 15A, passes through the cathode 15, the adhesive resin 28, the red filter 29R, the green filter 29G, the blue filter 29B, and the sealing substrate 27 to be sealed. It is taken out from the stop substrate 27 side.

  As described above, according to the present embodiment, the back surface 20B of the display panel 20, that is, the back surface configured to include the conductive material so as to cover the surface opposite to the organic electroluminescent elements 22R, 22G, and 22B. Since the layer 32A is provided, the back surface layer 32A shields the peripheral control circuit 25 and the wiring electrode 23, thereby preventing leakage of electromagnetic waves such as unnecessary radiation.

  Since the back layer 32A includes at least one member selected from the group consisting of simple substances, alloys, and compounds of copper, aluminum, zinc, iron and tin, it is an inexpensive material without using a transparent conductive material. High electromagnetic shielding ability can be expected. In addition, since the back surface layer 32A is located not on the light emitting surface 20A side of the display panel 20 but on the back surface 20B, there is no need to use a transparent conductive material that is expensive and laborious to manufacture, and is listed in the above group. Materials are enough.

  Further, since the heat conduction of the display panel 20 can be enhanced by the back layer 32A, the heat generated by the light emission of the organic electroluminescent elements 22R, 22G, and 22B is dissipated, and the temperature distribution inside the display panel 20 is made uniform. The In particular, if the back layer 32A is made of at least one of a simple substance, alloy, and compound of copper having a high thermal conductivity, a high heat dissipation effect can be obtained. In this case, it is more effective to use a silicone adhesive having a high thermal conductivity for the adhesive layer 33.

  Furthermore, since the back layer 32A is a thin plate-like member, it is useful for reinforcing the display panel 20. Suitable materials for the back layer 32A for reinforcement include, among others, simple iron, alloys and compounds. Moreover, by using a thin plate-like member, it can be easily manufactured or obtained, and can be easily attached by the adhesive layer 33.

[Second Embodiment]
FIG. 9 shows a self-luminous display device according to the second embodiment of the present invention. This self-luminous display device has the same configuration, operation, and effects as those of the first embodiment except that the back layer 32B is a film containing a conductive material. Therefore, the same components are denoted by the same reference numerals, and the description thereof is omitted.

  In the present embodiment, the back layer 32B is a film containing, for example, a ferrite-based material or graphite, and can function as an electromagnetic wave shielding film similarly to the back layer 32A in the first embodiment. In particular, in the case of a film containing graphite, in addition to the electromagnetic wave reduction effect, a synergistic effect that the temperature in the display panel 20 can be made uniform by the heat dissipation effect can be obtained.

[Third Embodiment]
FIG. 10 shows a self-luminous display device according to the third embodiment of the present invention. In this self-luminous display device, the back layer 32C is a metal layer formed on the surface opposite to the organic electroluminescent elements 22R, 22G, 22B of the display panel 20, except for the first embodiment. It has the same configuration, action and effect as the form. Therefore, the same components are denoted by the same reference numerals, and the description thereof is omitted.

  The metal used as the material for the back layer 32C can be at least one member selected from the group consisting of simple substances, alloys, and compounds of copper, aluminum, zinc, iron and tin, but is generally easy to form. To silver or silver alloys are preferred.

  Further, since the back layer 32C is provided on the back surface 20B of the display panel 20, there is no particular limitation on the film thickness and accuracy, and the back layer 32C is formed by at least one of plating, vapor deposition, and chemical vapor deposition. It can be. In particular, it is preferable to use chemical vapor deposition because the back layer 32C can be formed simultaneously with the manufacturing process of the display panel 20. The film thickness of the back layer 32C is not particularly limited as described above, but is desirably 100 μm or more in order to ensure good conduction performance.

  In the present embodiment, since the back layer 32C is a metal layer formed on the surface of the display panel 20 opposite to the organic electroluminescent elements 22R, 22G, 22B, the weight, appearance, and dimensions of the display panel 20 The wiring electrode 23 and the peripheral control circuit 25 can be shielded and the leakage of electromagnetic waves such as unnecessary radiation can be prevented.

  While the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above-described embodiment, the configuration of the organic electroluminescent elements 22R, 22G, and 22B has been specifically described. However, it is not necessary to include all the layers such as the insulating layer 13 or the transparent electrode 15B. These layers may be further provided. Note that the present invention can be applied to the case where the translucent electrode 15A is not provided. However, as described in the above embodiment, a resonator having the translucent electrode 15A and the anode 12 as a resonating unit. It is preferable to have the above because the reflectance of external light in the organic electroluminescent elements 22R, 22G, and 22B can be reduced and the contrast can be further improved.

  Moreover, as the drive control method of the display panel 20, the example of the active matrix method has been described in the above embodiment, but the present invention can also be applied to the case where the passive matrix drive control is adopted.

  Furthermore, in the above-described embodiment, an example in which the back layers 32A, 32B, and 32C cover only the back surface 20B of the display panel 20 has been described. However, the back layers 32A, 32B, and 32C cover the back surface 20B of the display panel 20 from the side surface. It may be formed. Further, the back layers 32A, 32B, and 32C may be formed so as to cover from the back surface 20B of the display panel 20 to the side surface and the peripheral portion of the light emitting surface 20A, and may also serve as the holding member 31.

  In addition, in the above-described embodiment, red, green and blue light is generated by changing the material of the organic layer 14, but the present invention combines color changing mediams (CCM). The present invention can also be applied to a display device that generates these lights by combining color filters.

1 is a cross-sectional view illustrating a configuration of a self-luminous display device according to a first embodiment of the invention. FIG. 2 is a plan view of a display panel in the self-luminous display device shown in FIG. 1. FIG. 3 is a cross-sectional view in a display area of the display panel shown in FIG. 2. FIG. 2 is an enlarged cross-sectional view illustrating a configuration of an organic electroluminescent element in the self-luminous display device illustrated in FIG. 1. FIG. 2 is an enlarged cross-sectional view illustrating a configuration of an organic electroluminescent element in the self-luminous display device illustrated in FIG. 1. FIG. 5 is a cross-sectional view illustrating a method of manufacturing the self-luminous display device illustrated in FIG. FIG. 7 is a cross-sectional view illustrating a process following FIG. 6. FIG. 8 is a cross-sectional diagram illustrating a process following the process in FIG. 7. It is sectional drawing showing the structure of the self-light-emitting display device which concerns on the 2nd Embodiment of this invention. It is sectional drawing showing the structure of the self-light-emitting display device which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 12 ... Anode (1st electrode), 13 ... Insulating layer, 13A ... Opening part, 14 ... Organic layer, 14A ... Hole injection layer, 14B ... Hole transport layer, 14C ... Light emitting layer, 14D ... Electron transport layer, 15 ... cathode (second electrode), 15A ... semi-transparent electrode, 15B ... transparent electrode, 20 ... display panel, 20A ... light emitting surface, 20B ... back surface, 21 ... substrate, 21A ... peripheral portion, 21B ... display region, 22, 22R, 22G, 22B ... organic electroluminescence element, 23 ... wiring electrode, 24 ... pixel circuit, 25 ... peripheral control circuit, 26 ... external connection interface, 27 ... sealing substrate, 28 ... adhesive resin, 29R ... red filter , 29G ... green filter, 29B ... blue filter, 30 ... black matrix, 31 ... holding member, 32A, 32B, 32C ... back layer, 33 ... adhesive layer

Claims (5)

The substrate on which the organic electroluminescent element is formed and the sealing substrate are arranged to face each other, and the entire surface is bonded by an adhesive resin. The organic electroluminescent element has a first electrode and a light emitting layer on the substrate. One or more organic layers including the second electrode and the second electrode, and a display panel for extracting light generated in the light emitting layer from the second electrode side;
An organic electroluminescent display device comprising: a back layer that includes a conductive material and is provided so as to cover a surface of the substrate on which the organic electroluminescent element is not provided. The organic electroluminescent display device according to claim 1, wherein the back layer is a film containing a conductive material. The organic electroluminescence display device according to claim 1, wherein the back layer is a film containing graphite. The organic electroluminescence display device according to claim 1, wherein the back layer is a thin plate member made of a conductive material. 2. The organic electroluminescence display device according to claim 1, wherein the back layer is a metal layer formed by at least one of plating, vapor deposition, and chemical vapor deposition.

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