Organic el display device

The present invention relates to a display device using an organic EL element, and more particularly to a technique for improving the moisture resistance of a light emitting layer.

Currently, as a next-generation display, a flat panel display (FPD), which is superior in space saving and power saving compared to existing CRTs and the like, is attracting attention. As a type of this FPD, research and development of an organic EL display device in which an organic electroluminescence element (hereinafter referred to as "organic EL element") is integrated as a light emitting cell is being actively carried out.

The configuration of the organic EL display device is as shown in the partial cross-sectional view showing the conventional configuration of FIG. 7. That is, the plurality of organic EL elements 10 each have a light emitting layer 102 capable of emitting white light, for example, a hole injection electrode (also referred to as "anode" or "anode") 101 and an electron injection electrode ("cathode" or "cathode"). It also has a configuration sandwiched between 11). As shown in this figure, the organic EL element called the top emission (TE) type has the light emitting layer 102 overlaid on the hole injection electrode 101 made of a metal material patterned on the substrate, and ITO and IZO are superposed on the hole injection electrode 101. Alternatively, it has a structure in which a transparent electrode such as a thin film metal or an electron injection electrode 11 composed of a translucent electrode is laminated. As a result, the light emitted from the light emitting layer 102 during driving is not blocked by the substrate, and the side on which the electrode injection electrode 11 is arranged can be taken out as the front surface. The hole injection electrode made of the metal material also serves to reflect the light emitted from the light emitting layer 102 to the front surface and improve the luminous efficiency.

In the case where each organic EL element 10 emits light of the same color (white) as in the above configuration, it can be provided across a plurality of organic EL elements. At this time, the light emitting layer 102 and the electron injection electrode 11 can be arranged by a vapor deposition method or the like. For the substrate, for example, an active matrix type TFT substrate 30 or the like is used. The light emitting layer 102 can be formed by, for example, laminating a blue light emitting layer and an orange light emitting layer. Then, according to the arrangement position of each organic EL element 10, any of the three primary color filters 61R, 61G, 61B or a transparent substrate on which a color conversion layer (not shown) is laminated is provided so as to face each other, so that the entire substrate can be multi-layered. The image is displayed in color or full color. The method using a color filter does not require mixing a phosphor material in each light emitting layer 102 or separately painting the elements, and simplifies the process, which is suitable for cost reduction and a high-definition display. Is.

A black matrix BM may be arranged in the gap between the color filters 61R, 61G, and 61B to improve visibility. In general, the thicknesses of the color filters 61R, 61G, and 61B corresponding to each color are different. Therefore, for the purpose of eliminating the unevenness of the thickness as a whole, for example, as in Patent Document 1, the color filters 61R, 61G, 61B are made of acrylic. It is overcoated with a flat film 60 made of a base resin, an epoxy resin, or the like.

Here, the light emitting layer 102 in the organic EL element 10 has a property of being vulnerable to moisture. Therefore, when the light emitting layer 102 comes into contact with water, it deteriorates, which may adversely affect the display performance such as a decrease in light emission intensity and a deterioration in life. Therefore, in the organic EL display device, it is necessary to isolate the light emitting layer 102 from the moisture in the outside world as much as possible.<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2003-248440</text></patcit>

<p> However, the organic EL display device having the above configuration has the following problems. First, it cannot be said that the current organic EL display device has sufficient moisture-proof measures for the light emitting layer 102 to the extent that the generation of non-lighting areas (so-called dark spots) is eliminated. As a result of diligent studies by the inventor of the present application, the main infiltration route of water to the light emitting layer 102 is considered to be the interface between the TFT substrate 30 and the adhesive layer 5 as well as the interface between the flat film 60 and the adhesive layer 5. ..</p><p> Of these, as shown in the conventional diagram of FIG. 7, the interface (L5 + L6) between the flat film 60 and the adhesive layer 5 is a portion to be particularly noted. When moisture penetrates into the interface, the moisture diffuses widely over the entire display, causing non-lighting areas (so-called dark spots) to occur, which causes a significant decrease in display performance. Secondly, there is a problem with the visibility of the display in the current organic EL display device. In the current display, color mixing may occur between adjacent elements as the viewing angle increases, and the desired color reproduction may not be performed well. Such a visibility problem is a problem to be solved particularly in the case of a configuration that forms a full-color display.</p><p> The present invention has been made in view of the above problems, and the first object of the present invention is to realize good display performance by exhibiting high moisture resistance particularly in the vicinity of a transparent substrate on which a color filter is arranged. The purpose is to provide a possible organic EL display device. The second purpose is to provide an organic EL display device having better color reproduction than the conventional one.</p>

<p> In order to solve the above problems, the present invention is an organic light emitting display device in which a back panel having a plurality of organic light emitting elements arranged on the surface of a TFT substrate is arranged so as to face the front panel. Is formed by laminating a color filter or a color conversion layer on the surface of the transparent substrate so as to face the organic light emitting element on the TFT substrate, and the color filter or the color is sandwiched between the front panel and the back panel. It was assumed that a single adhesive layer for adhering both panels was arranged so as to directly cover the conversion layer.</p><p> Here, the plurality of organic light emitting elements are arranged in a matrix on the surface of the TFT substrate, and a color filter corresponding to each display color is provided so as to display different colors along any direction of the matrix of the matrix. It can be arranged. Further, the plurality of organic light emitting elements are repeatedly arranged along any direction of the matrix of the matrix so as to correspond to the three primary colors, and the color filter is for each element corresponding to the three primary colors or a matrix for displaying the same color. It is assumed that they are provided corresponding to adjacent element groups in this direction.</p><p> Further, in the present invention, it is assumed that a sealing member made of a material different from the adhesive layer material is arranged between the TFT substrate and the transparent substrate so as to surround the matrix of the plurality of organic light emitting elements. .. Further, in the present invention, a film thickness adjusting layer for adjusting the laminated thickness can be further laminated on the color filter or the color conversion layer formed on the transparent substrate.</p><p> Further, a black layer is formed on the transparent substrate so as to match the gaps between adjacent color filters, and the thickness of the black layer can be set to be equal to or greater than the maximum thickness of the color filter.</p>

<p> As described above, in the organic light emitting display device of the present invention, the color filter provided on the transparent substrate on the front panel is not coated with the flattening film as in the conventional configuration, but is directly coated with a single adhesive layer. .. Therefore, in the present invention, in the front panel, in addition to the color filter provided on the transparent substrate and, in some cases, the color filter, there are irregularities corresponding to the thicknesses of the color conversion layer and the black layer (black matrix). Therefore, by filling and arranging the adhesive layer so as to enter the unevenness, the specific surface area of the interface between the adhesive layer and the front panel (the interface with respect to the area when viewed in a plan view) as compared with the conventional example of FIG. 7 above. The area along the interface (hereinafter referred to as "interface distance") corresponding to a certain distance on the panel plane is set longer. The longer the interface distance, the slower the rate at which moisture penetrates into the display. Therefore, in the present invention, the rate at which moisture penetrates into the device using the interface as the penetration path is delayed as compared with the conventional case, resulting in good moisture-proof measures. It will be exhibited, and the life of the device will be extended.</p><p> In particular, when color display is performed using the three primary colors of RGB in an organic EL display device, a plurality of filters corresponding to each color are arranged for each adjacent cell in any direction of the matrix matrix. In the case of such a configuration, the interface distance is secured long in proportion to the number of arrangements of the color filters, and the moisture-proof effect of the present invention can be satisfactorily obtained. The reason why the adhesive layer of the present invention is single is that when a plurality of adhesive layers are used, for example, as a laminated structure, a new interface is generated between different adhesive layers, which may serve as a moisture infiltration route. Because of its nature, it was set for the purpose of eliminating this.</p><p> Further, the present invention is not limited to the three primary colors and full-color display, and the color filters may be arranged at a plurality of locations on the surface of the transparent substrate. Therefore, the same effect can be expected even in the case of a configuration for displaying a single color, for example. .. Further, in the present invention, by laminating a film thickness conversion layer on a color filter or the like, the surface area of the interface can be further increased, the infiltration of water can be delayed, and effective moisture-proof measures can be taken. </p><p> Further, in the present invention, the surface area of the front panel can be increased and the moisture-proof effect can be obtained by arranging the black matrix so that the film thickness is thicker than that of the color filter. On the other hand, by reliably partitioning adjacent elements from each other by a black matrix formed on a thick film, it is possible to prevent the occurrence of color mixing even if the viewing angle increases, and to exhibit excellent display performance.</p>

(Embodiment 1) 1-1. Overall configuration of the TFT type organic EL display device FIG. 1 is a top view showing a partial configuration of the TFT type organic EL display device according to the first embodiment of the present invention. Further, FIG. 2 is a partial cross-sectional view of the organic EL display device. First, as shown in FIGS. 1 and 2, the organic EL display device 1 is composed of a front panel FP and a back panel BP, and an adhesive layer 5 and the like arranged between both substrate FPs and BPs. It has a top emission structure that extracts light from the panel FP (upper side of the paper in Fig. 1).

The back panel BP is composed of a TFT substrate 30, a plurality of organic EL elements 10, a cell separation membrane 15, a protective film 4, and the like. The TFT substrate 30 is a known one having a TFT having an active layer made of polycrystalline silicon or the like, which is also used for LCD (liquid crystal display), and is formed on a main substrate 2 made of an inorganic material such as glass, for example, FIG. As shown in the circuit diagram of, the power supply line 103, the common gate line 1002, the capacitors C, the TFTs 1, 2 and the like are formed by a predetermined wiring pattern. Of these, capacitors C, TFTs 1 and 2 are provided at positions corresponding to each organic EL element 10. A known line driver is connected to the common gate line 1002, the power supply line 103, the common cathode 11 described later, and the like, and a predetermined pulse based on a video signal input from the outside is applied. ing.

A flattening film 3 made of an insulating material is formed on the surface of the main substrate 2 of the TFT substrate 30 so as to embed the wiring pattern. The flattening film 3 exhibits stability to the device mounted on the film, and thus plays a role of exhibiting stability at the time of positioning, joining, and the like. Such a flattening film 3 has a partial gap, and a region for exposing the wiring pattern is provided in accordance with the gap, whereby various connections with the wiring pattern, for example, as shown in FIG. 2, are provided. The anode 101 of each organic EL element 10 is connected to the power supply line 103, or the TFT 2 is connected to the common cathode 11.

Each organic EL element 10 has a configuration in which an anode (hole injection electrode) 101 as a first electrode, a light emitting layer 102, and a common cathode 11 (electron injection electrode) as a second electrode are laminated in the same order from the TFT substrate 30 side. Become. The anode 101 is made by processing a metal material such as Mo or Cr to a thickness of about 100 nm, and as shown in the element lower layer region along the X-ray in FIG. 1, the column direction is the longitudinal direction and the row direction is It is attached in multiple stripes. As a result, any one of the anodes 101 becomes a common electrode for the plurality of organic EL elements 10 for each line arranged in the row direction.

The common cathode 11 is constructed by processing a transparent electrode material such as ITO or IZO in a thickness range of 10 nm to 20 nm, and is entirely arranged for all organic EL elements 10 (see FIG. 2). ). In FIG. 1, the common cathode 11 is not shown for internal explanation. The light emitting layer 102 is configured to emit white light by laminating, for example, a light emitting layer that emits blue light and a light emitting layer that emits light in orange, which has a complementary color relationship with blue. Although not shown in FIGS. 1 and 2, more specifically, under the light emitting layer 102, a hole injection layer made of a triphenylamine derivative having a thickness of 100 nm and a diamine having a thickness of 20 nm are formed from the TFT substrate 30 side. Hole transport layers made of derivatives are sequentially laminated. In such a configuration example of the light emitting layer 102, 1000 to 3000 cd / m is applied by applying a drive voltage of 5 to 10 V.²It can exhibit a certain degree of brightness.

In the present invention, as shown in FIGS. 1 and 2, when all the organic EL elements 10 emit light of the same color (white), the organic EL elements 10 straddle the plurality of organic EL elements 10 and emit light by a vapor deposition method or the like. A layer 102 and a common cathode 11 (electron injection electrode) can be provided. Further, the emission display color at the time of driving is adjusted by arranging the color filters 61R, 61G and 61B described later.

Further, in the TFT substrate 30, a lattice-shaped cell separation membrane 15 for separating and partitioning each element 10 is formed so as to sandwich the organic EL element 10 having the above configuration. The cell separation membrane 15 is made of an insulating material having a trapezoidal cross-sectional shape, and is formed so as to cover the edge portion 1010 of each anode 101 exposed from below the organic EL element 10 as shown in FIG. There is. This is because the shape of the edge portion 1010 is relatively sharp because it is produced by processing such as photoetching, so it is covered so that it does not partially contact the different polar part and cause a short circuit. It was made for the purpose of protection. It is also arranged for the purpose of preventing the problem of color mixing between adjacent organic EL elements 10.

The protective film 4 is obtained by sputtering or vapor-depositing an insulating material (a material having high transparency in the visible region, electrical insulation, and a barrier property against moisture, oxygen, etc., for example, SiOx, SiNx, AlOx, etc.). It is constructed by forming a film by a method, a CVD method, or the like, and is arranged so as to cover and seal both the organic EL element 10 and the cell separation film 15 forming the matrix arrangement. The protective film 4 serves to protect the film by including the organic EL element 10, and is provided for the purpose of preventing moisture from entering from the outside of the apparatus and deteriorating the light emitting layer 102.

The adhesive layer 5 is transparent using a material having a visible light transmittance and a refractive light of 1.3 to 2.5, for example, an organic material such as transparent silicone rubber, transparent silicone gel, epoxy resin, or acrylic resin. It is made of excellent materials and has a single structure as a whole of the adhesive layer 5. The back panel BP is provided so as to cover one main surface of the TFT substrate 30 from above the protective film 4, and the front panel FP is provided with color filters 61R, 61G, 61B and the color filters 61R, 61G, 61B from the surface of the transparent substrate 6. It is provided so as to directly cover the black matrix BM. The adhesive layer 5, together with the protective film 4, also serves to isolate and maintain the light emitting layer 102 from the moisture in the outside world.

As a method of forming the adhesive layer 5, a printing method such as a thick film forming method is used in addition to a method of arranging the front panel FP and the back panel BP facing each other and then filling between the two panel FPs and BPs under reduced pressure conditions. Then, a method of applying the coating to both panel surfaces or one of the panel surfaces and bonding them under reduced pressure can also be mentioned. The "adhesive layer 5" in the present invention has a single structure, and does not include, for example, an adhesive layer having a laminated structure made of a plurality of different materials. Furthermore, it does not include materials made of different materials, such as a "flat film" that was conventionally formed to cover the surface of the front panel FP. This is because the presence of different materials inside the adhesive layer 5 itself prevents the formation of an interface that can be a moisture infiltration route.

On the other hand, the front panel FP is composed of a transparent substrate 6, color filters 61R, 61G, 61B, black matrix BM and the like. The transparent substrate 6 can be made of, for example, a highly transparent soda lime glass material or a non-alkali glass material. The color filters 61R, 61G, and 61B are individually provided on the surface of the transparent substrate 6 according to the gap positions of the cell separation membrane 15 so as to correspond to the respective positions of the organic EL elements 10 provided on the back panel BP. Be done. In the first embodiment, the color filters 61R, 61G, and 61B are formed in a band shape along the column direction of the matrix, and are shared by a group of white organic EL elements 10 arranged in the column direction. ing.

As a method of arranging the color filters 61R, 61G, and 61B, one may be provided for each cell. Further, although not shown in FIG. 2, a color conversion layer may be provided by laminating one above or below the color filters 61R, 61G, and 61B, or the color conversion layer may be used alone. The color conversion layer is for adjusting the emission color at the time of driving.

The black matrix BM is a so-called black layer, and is provided so as to match the gaps between the color filters 61R, 61G, and 61B and surround each organic EL element 10 when viewed from the front of the display. In this configuration example, the black matrix BM is formed of a thinner film than the color filters 61R, 61G, and 61B. According to the organic EL display device 1 having the above configuration, as shown in the circuit diagram of FIG. 3 during driving, when power is first supplied to any of the individual power supply lines 103 and the common gate line 1002, the TFT 1 Switching is performed at, and data is written to the capacitor C connected to the switching. After that, by supplying power to the anode 101 and the common cathode 11 via the power supply line 103, light is emitted from the organic EL element 10 corresponding to the position of the capacitor C in which the data is written. At this time, since the output from the capacitor C to which the data is written is sent to the arbitrary organic EL element 10 side via the TFT 2 connected to the capacitor C, the output is adjusted in the TFT 2. As a result, the emission intensity of the element is adjusted.

1-2. Features of the present embodiment The feature of the first embodiment is that the color filters 61R, 61G, and 61B each come into direct contact with the adhesive layer 5 on the surface of the transparent substrate 6 of the front panel FP. It is in the point that it is arranged in. By taking such measures in the display device 1, a large surface area of the front panel FP facing the adhesive layer 5 is secured, and water infiltrates from the outside of the device through the contact interface between the front panel FP and the adhesive layer 5. As a result, high moisture resistance is exhibited for a relatively long period of time.

Specifically, the surface of the transparent substrate 6 on which the color filters 61R, 61G, 61B and the black matrix BM corresponding to each color are arranged is conventionally formed by a flat film 60 having a flat surface so as to overcoat them. Since it was formed (see FIG. 7), the interface between the adhesive layer 5 and the flat film 60 is flat. Therefore, when water infiltrates from the outside of the device using this interface as an infiltration path (L5 + L6), it permeates to the center of the display at a relatively early time, and the gap G from the interface to the back panel BP._R, G_B, G_GMoisture may be mixed into the light emitting layer 102 of the back panel BP to form a dark spot (non-lighting region). On the other hand, in the first embodiment, the surface area of the front panel FP is increased by the area of the wall surface formed by the difference in the layer thickness between the color filters 61R, 61G, 61B and the black matrix BM. Even if water infiltrates through the infiltration route, the infiltration rate of water is delayed. The light emitting layer 102 originally has a chemical property of being weak against water, but in the first embodiment, the deterioration of the light emitting layer 102 is suppressed under high moisture resistance due to the delay effect of water infiltration, and the light emitting layer 102 is dark. It is possible to prevent frequent occurrence of spots and realize stable light emission performance and display performance for a relatively long period of time.

The present invention is characterized in that the surface area of the front panel FP is increased as compared with the conventional configuration using a flat film, but the pattern shape, stacking thickness, etc. of the color filters 61R, 61G, 61B and the black matrix BM, etc. Even if the setting of is the same as the conventional one, the surface area of the front panel FP increases unless the flat film 60 is formed. However, as described in the configuration of FIG. 2 above as well as in other embodiments, the thickness of at least one of the color filters 61R, 61G, 61B and the black matrix BM is increased, resulting in a further increase in the surface area of the front panel FP. This is desirable because the rate of water infiltration can be further delayed. Even if the color filters 61R, 61G, 61B and the black matrix BM have the same film thickness, the surface area of the front panel FP increases slightly unless the flat film 60 is used.

Hereinafter, other embodiments will be described focusing on the differences from the first embodiment. (Embodiment 2) FIG. 4 is a cross-sectional view of the device showing the configuration of the organic EL display device according to the second embodiment of the present invention. The difference from the first embodiment is that when the color filters having different colors have different thicknesses, the thick film adjusting layers 62R and 62G are laminated on the thin color filters (61R and 62G in this case), and all the colors are used. The point is that the apparent thickness of the filter is adjusted to be the same. The film thickness adjusting layers 62R and 62G are made of a material having excellent transparency.

Even with such a configuration, the same effect as that of the first embodiment can be obtained. In particular, by providing the film thickness adjusting layers 62R and 62G, the unevenness of the front panel FP surface becomes larger and the surface area thereof also increases, so that moisture penetrates from the outside of the device through the interface L2 with the adhesive layer 5. In this case, the penetration rate is effectively delayed as compared with the first embodiment, and stable driving is possible for a long period of time.

Further, in the second embodiment, by providing the film thickness adjusting layers 62R and 62G, the gap G between the color filters 61R, 61G and 61B and the back panel BP is G._R, G_G, G_BIs adjusted to a certain distance, so that the viewing angle dependence of each RGB color can be made uniform, and there is also the advantage that excellent emission color characteristics are exhibited. (Embodiment 3) FIG. 5 is a cross-sectional view of the device showing the configuration of the organic EL display device according to the third embodiment of the present invention.

The configuration of the third embodiment is basically the same as that of the first embodiment, but the thickness of the black matrix BM is made thicker than the maximum thickness of the color filters 61R, 61G, and 61B (here, 61B). It is at the set point. According to such a configuration, the surface area of the front panel FP is increased by the amount of the black matrix BM film thickness, so that the same effect as that of the first embodiment is more effectively exhibited, and a high moisture-proof effect is obtained. Quality reliability is ensured. In particular, in the first embodiment, since the black matrix BM protrudes more than the surface of the transparent substrate 6, the moisture that has penetrated into the interface L3 with the adhesive layer 5 from the outside is effectively blocked by the barrier of the black matrix BM. Therefore, the moisture is the gap G between the black matrix BM and the back panel BP._BMIt is difficult to penetrate into the back panel BP side.

Further, in the third embodiment, since the color filters 61R, 61G, and 61B are surrounded by the thick black matrix BM, color mixing between different adjacent colors is prevented over a wide viewing angle. It is also possible to exhibit good emission color characteristics. In the third embodiment, an example in which the thickness of the black matrix BM is made thicker than the maximum thickness of the color filters 61R, 61G, 61B has been described, but the thickness of the black matrix BM is not necessarily the thickness of the color filters 61R, 61G, 61B. It is not necessary to make it thicker than the maximum thickness, and even if it is formed slightly thinner, a certain effect can be expected.

(Embodiment 4) FIG. 6 is a cross-sectional view of the device showing the configuration of the organic EL display device according to the fourth embodiment of the present invention. In the fourth embodiment, the internal structure is the same as that in the first embodiment, but in addition to this, the side surface of the adhesive layer 5 on the peripheral edge (outermost circumference) of the panel is sealed with a moisture-proof material so as to surround the adhesive layer 5. It is characterized in that a moisture-proof wall 7 is provided as a stopping member.

As the material of the moisture-proof wall 7, for example, a visible light-curable adhesive, a thermosetting adhesive, an ultraviolet-curable adhesive, or a material made of a water-repellent fluorine compound such as PTFE is used to further prevent moisture. May be increased. According to the fourth embodiment having such a configuration, it is possible to further suppress the infiltration of water as compared with the first embodiment. In particular, in the fourth embodiment shown in FIG. 6, since the moisture-proof wall 7 is provided so as to fit into the gap between the transparent substrate 6 and the TFT substrate 30, in addition to the interface L4 between the front panel FP and the adhesive layer 5, A moisture-proof effect is also exhibited at the interface between the adhesive layer 5 and the TFT substrate 30. Therefore, more stable driving and long-term stability have been realized.

The moisture-proof wall 7 does not need to completely surround the panel, and even if it is provided in a part of the area, some effect can be expected. (Example) Here, in order to confirm the effect of the present invention, the organic EL display devices of Examples and Comparative Examples were prepared and driven to evaluate the performance.

&lt;Measurement Experiment 1&gt; The organic EL display devices of the above embodiments 1 to 4 were produced as Examples 1 to 4, respectively. Further, the configuration shown in FIG. 7 was used as Comparative Example 1, and the configuration provided with the same moisture-proof wall 7 as in the fourth embodiment was prepared as Comparative Example 2, respectively. The experimental items are high temperature and humidity resistance experiments (85 ° C / 85% RH, elapsed time conditions) and measurements in the viewing angle dependence of the display.

The experimental results are shown in Table 1 below. The numerical values described are relative values when the data of Comparative Example 1 is used as a reference.

<tables num="1"><img file="JP2005293946A_D0001.tif" /></tables> &lt;Measurement Experiment 2&gt; Next, with respect to the organic EL display device of the first embodiment, an investigation experiment was conducted on the film thickness and the water infiltration rate of the color filter. In the experiment, the film thickness of the color filter was changed in the range of 0.5 μm to 20 μm, which corresponds to the film thickness of the filter formed on the actual organic EL display device, and Examples 5 to 14 were prepared.

Further, an organic EL display device in which a flat film was overcoated on the front panel FP and this was combined with an active matrix type back panel BP without a separation film was produced as Comparative Example 3. Further, an organic EL display device in which a flat film was overcoated on the front panel FP and combined with the back panel BP using a TFT substrate was produced as Comparative Example 4.

The panel size was 2.4 inches QVGA standard (320 x 240 x RGB), and the size of the display was 3.6 cm x 4.8 cm (diagonal 6.0 cm). On the surface of the TFT substrate to be used, a flattening film having a thickness of 1.0 μm was used for each cell composed of each organic EL element. Here, the calculation was performed on the assumption that the flattening film of the TFT substrate has a rectangular cross section. The experimental results are shown in Table 2 below.

R-CF, G-CF, and B-CF indicate red, green, and blue color filters, respectively. The "distance ratio (TFT / CF)" in Table 2 refers to the length along the surface of the TFT substrate (TFT) and the length along the interface of the front panel FP in the cross section along the lateral direction of the panel (TFT). It shows the ratio of CF). Further, the "distance to the light emitting center" in Table 2 represents the distance from the lateral end portion of the panel to the central portion along the interface between the front panel FP and the adhesive layer.

Further, the water vapor arrival time in Table 2 represents the time until the water vapor reaches the central portion of the panel. The numerical values in parentheses after Example 12 represent the difference from the time of Examples 5 to 11.

<tables num="2"><img file="JP2005293946A_D0002.tif" /></tables> &lt;Results and Discussion&gt; First, from the data shown in Table 1, all of the organic EL display devices of Examples 1 to 4 of the present invention are superior to the organic EL display devices of Comparative Examples 1 and 2 having the conventional configuration in terms of moisture resistance. It became clear that it has other characteristics. As a result of conducting a high temperature and high humidity experiment, it is presumed that the organic EL display device of the present invention effectively suppressed the infiltration of water and exhibited high resistance.

On the other hand, from the data of Comparative Example 2, it was found that simply providing a moisture-proof wall around the panel does not improve the moisture resistance so much as compared with the conventional configuration. Therefore, in order to take effective moisture-proof measures, it is basically necessary to increase the surface area of the front panel FP at least as in Example 1 in the present invention, and by doing so, even if the front panel FP is taken. Even if water infiltrates the interface end of the adhesive layer 5, the infiltration rate is delayed, so stable driving can be expected over the entire panel.

It was also found that the performance of the viewing angle was not inferior to that of the conventional Comparative Examples 1 and 2 in Examples 1 to 4. In particular, in Example 3, since the black matrix is formed so as to be a thicker film than the color filter, it was found that high display performance is exhibited by preventing the occurrence of problems such as color mixing. As described above, the present invention is also effective as a measure for improving the display performance of the organic EL display device.

Next, from the data in Table 2, even if the thickness of the color filter is in the small value range of 0.5 μm to 1 μm as in Examples 12 to 14, as a result, it is shown in the distance to the emission center. In addition, since the surface area of the front panel FP is increased, the moisture-proof effect is higher than that of Comparative Example 3 or 4. In the examples, the moisture-proof effect increases as the thickness of the color filters increases, but in the experiment, as shown in the data of Examples 5 to 11, the thickness of each color filter all exceeded 1.0 μm, and the thickness of the separation membrane was increased. When it exceeds, the moisture-proof effect of the organic EL display device becomes dependent on the moisture-proof effect in the penetration path between the TFT substrate and the adhesive layer, and the apparent moisture penetration rate due to the effect of the present invention becomes constant. Therefore, in order to obtain a higher moisture-proof effect, for example, as shown in the fourth embodiment (Example 4), a device such as providing a moisture-proof wall so that the moisture-proof effect from the vicinity of the TFT substrate can also be obtained is devised. There is a need to do. The configuration of the fourth embodiment is based on the configuration of the first embodiment, and can be realized only by surrounding the panel with a moisture-proof material. Therefore, a relatively simple configuration can be expected to have a high moisture-proof effect, which is preferable.

From the data of the examples shown in Table 2, the following relationship is established. That is, the thickness of the color filter laminated on the surface of the transparent substrate is in the range of 0.5 μm or more and 20 μm or less, and the thickness of the flat film formed on the TFT substrate is in the range of 0.5 μm or more and 2.0 μm or less. When the interface length between the front panel and the adhesive layer in one section of the light emission display device is a and the interface length between the back panel and the adhesive layer in the one section is b, 0.57 b / a 1.02. It is considered desirable to set the relationship so that a high moisture-proof effect can be obtained. When b / a is larger than 1.02 or b / a is less than 0.57, it is difficult to obtain a favorable effect. However, this numerical range depends on the thickness of the flat film of the color filter and the TFT substrate, and the optimum range changes as these sizes change.

The organic EL display device of the present invention can be used for displays of portable electronic devices, full-color televisions, and the like.

<figref num="1">It is a top view of the organic EL display device of Embodiment 1.</figref><figref num="2">It is sectional drawing of the organic EL display device of Embodiment 1. FIG.</figref><figref num="3">It is a schematic wiring diagram of Embodiment 1.</figref><figref num="4">It is sectional drawing of the organic EL display device of Embodiment 2.</figref><figref num="5">It is sectional drawing of the organic EL display device of Embodiment 3.</figref><figref num="6">It is sectional drawing of the organic EL display device of Embodiment 4.</figref><figref num="7">It is sectional drawing of the conventional organic EL display device.</figref>

Code description

1 Active matrix type organic EL display device 2 Main substrate 3 Flattening film 4 Protective film 5 Adhesive layer 6 Transparent substrate 10 Organic EL element 11 Cathode, common cathode (electron injection electrode) 15 Cell separation membrane 61R, 61G, 61B Color filter 101 Anode (Hole injection electrode) 102 Light emitting layer 1010 Edge part