ORGANIC ELECTROLUMINESCENT DISPLAY DEVICE

Abstract

The present invention provides an organic EL display device which can maintain a light emitting efficiency and can prolong a lifetime by suppressing the degradation of an organic light emitting layer attributed to moisture. The organic EL display device includes a sealing film formed of an organic film which covers an organic light emitting layer which is constituted of a first electrode which is formed on a main surface of an insulation substrate, an organic EL layer of the multi-layered structure, and a second electrode and has a peripheral end portion sealed to a peripheral portion of the insulation substrate. The organic EL display device includes a moisture-resistant structural body which covers an upper surface and a side surface of the organic light emitting layer and is formed by stacking a first moisture prevention layer, a moisture absorption layer and a second moisture prevention layer in this order. The first moisture prevention layer, the moisture absorption layer and the second moisture prevention layer on the side surface of the organic light emitting layer are bent toward the side surface from the upper surface of the organic light emitting layer and, further, are bent parallel to a main surface of the insulation substrate from the side surface, and lower surfaces of the respective bent portions are hermetically adhered to the main surface of the substrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an essential part for explaining the schematic structure of an organic EL display element of the present invention;

FIG. 2 is a cross-sectional view of an essential part for explaining a structural example of a light emitting layer;

FIG. 3 is a cross-sectional view of an essential part for explaining the basic structure of an organic EL display device according to the present invention;

FIG. 4 is a cross-sectional view of an essential part for explaining the structure of an embodiment 1 of the organic EL display device according to the present invention;

FIG. 5 is a cross-sectional view of an essential part for explaining the structure of an embodiment 2 of the organic EL display device according to the present invention;

FIG. 6 is a cross-sectional view of an essential part for explaining another constitutional part of the organic EL display device representing the organic EL display device explained in conjunction with the embodiment 1;

FIG. 7 is an explanatory view of one example of a pixel circuit which constitutes the organic EL element;

FIG. 8 is an equivalent circuit diagram for explaining an example of the whole constitution of the organic EL display device according to the present invention; and

FIG. 9 is a schematic cross-sectional view of an essential part of the organic EL display device having the conventional sealing can structure.

Claims

1. An organic EL display device comprising: a first electrode which is formed on a main surface of an insulation substrate;an organic EL layer of the multi-layered structure which is formed on the first electrode;a second electrode which is formed on the organic EL layer; anda sealing member which covers the second electrode and has a peripheral end portion thereof sealed to a peripheral portion of the insulation substrate, whereinthe organic EL display element includes a moisture-resistant structural body which covers an upper surface and a side surface of the organic EL layer and is formed by stacking a first moisture prevention layer, a moisture absorption layer and a second moisture prevention layer, whereinthe first moisture prevention layer, the moisture absorption layer and the second moisture prevention layer on the side surface of the organic EL layer are bent toward the side surface from the upper surface of the organic EL layer and, further, are bent parallel to a main surface of the insulation substrate from the side surface, and lower surfaces of the respective bent portions are hermetically adhered to the main surface of the substrate.

2. An organic EL display device according to claim 1, wherein an adhesive layer is formed between the moisture absorption layer and the second moisture prevention layer, and the first moisture prevention layer and the moisture absorption layer are fixedly mounted on the main surface of the substrate by the adhesive layer together with the second moisture prevention layer.

3. An organic EL display device according to claim 2, wherein the first moisture prevention layer is made of silicon nitride, the moisture absorption layer is made of calcium and the second moisture prevention layer is made of aluminum.

4. An organic EL display device according to claim 1, wherein a first adhesive layer is formed between the organic EL layer and the first moisture prevention layer, and a second adhesive layer is formed between the first moisture prevention layer and the moisture absorption layer, and the first moisture prevention layer is fixedly mounted on the main surface of the substrate by the first adhesive layer and, at the same time, the moisture absorption layer and the second moisture prevention layer are fixedly mounted on the main surface of the substrate by the second adhesive layer.

5. An organic EL display device according to claim 4, wherein the first moisture prevention layer is formed of an aluminum foil, the moisture absorption layer is made of zeolite (a product name), and the second moisture prevention layer is formed of an aluminum foil.

6. An organic EL display device according to any one of claims 2 to 5, wherein the sealing member is formed of a laminate film made of polyethylene terephthalate.

7. An organic EL display device according to any one of claims 2 to 6, wherein a caulking agent is applied to a periphery of the sealing member and a sealing region of the insulation substrate.

8. An organic EL display device according to claim 7, wherein the caulking agent is a silicon-based waterproof caulking agent.