JP2009104828A - Organic electroluminescent panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL panel of a multiple matrix structure capable of maintaining excellent appearance even after an elapse of time of use. <P>SOLUTION: The organic EL panel has an organic EL element formed by laminating an organic layer at least having a light-emitting layer between a first electrode 1 formed on the substrate and a second substrate 2 formed so as to cross the first electrode 1. The first electrode 1 has a plurality of pixel electrodes 1a arranged in a crossing direction to the second electrode 2, and wiring electrodes 1b connected to the pixel electrodes 1a. The pixel electrodes 1a connected to the different wiring electrodes 1b are made adjacent to each other in a crossing direction with the second electrode 2 to make up a unit. The second electrode 2 is separately formed in a line so as to oppose one unit of the pixel electrodes 1a by a first barrier rib 4 formed in crossing the first electrode 1. A second barrier rib 5 is so as to be positioned between the pixel electrodes 1a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic EL panel using an organic EL (electroluminescence) element, and more particularly to a passively driven organic EL panel.

  Conventionally, a passive driving method is known as a driving method for an organic EL panel in which an organic EL element which is a self-luminous element is provided on a light-transmitting substrate. In the passive drive organic EL panel, the first electrode is formed in a plurality of lines on the translucent substrate, and the second electrode is formed in a plurality of lines so as to intersect the first electrode. It has a matrix structure in which the intersection position of the electrode and the second electrode is a light emitting pixel (see, for example, Patent Document 1). In general, the second electrode is separated and formed by barrier ribs formed in a line shape. In such an organic EL panel, a line-sequentially scanned image is displayed on the display unit. The passive drive organic EL panel has the advantage that it is easier to manufacture than the active drive system.

As an electrode structure of a passively driven organic EL panel, for example, a so-called multiple matrix structure disclosed in Patent Document 2 is known. Such a multi-matrix structure controls lighting of a plurality of rows of light emitting pixels during one-line scanning of the scanning electrode. Even when the number of dots in the column direction is increased, the luminance life is reduced, the voltage is increased or the consumption current is increased. It is possible to suppress an increase in power consumption.
JP 2003-142258 A Japanese Patent Laid-Open No. 2001-217081 Japanese Patent Application Laid-Open No. 2000-21565 JP 2003-257663 A

  Here, in each light emitting pixel, as the usage time elapses, moisture and oxygen enter through the gaps of the partition walls to generate non-light emitting portions called dark frames. In the simple matrix structure, since the barrier ribs are formed between the columns of the light emitting pixels, the generation of the dark frame is common to all the light emitting pixels, and the appearance is unlikely to be strange. On the other hand, in the multi-matrix structure, since the scanning electrodes are opposed to a plurality of signal electrodes (pixel electrodes) in the column direction, the partition walls are not formed between the light emitting pixels constituted by the same scanning electrodes. For this reason, the light emitting pixel also has a problem in that the appearance and progress of the dark frame are different between the portion adjacent to the partition wall and the portion not adjacent to the partition wall, and the appearance is likely to be uncomfortable with the passage of time of use.

  An object of the present invention is to provide an organic EL panel capable of maintaining a good appearance even when a usage time has elapsed in an organic EL panel having a multiple matrix structure, paying attention to the above-described problems.

  In order to solve the above-mentioned problems, the present invention provides an organic layer having at least a light emitting layer between a first electrode formed on a substrate and a second electrode formed so as to intersect the first electrode. An organic EL panel including an organic EL element formed, wherein the first electrode includes a plurality of pixel electrodes arranged in a crossing direction with the second electrode and a wiring electrode connected to the pixel electrode. A plurality of the pixel electrodes connected to the different wiring electrodes are formed adjacent to each other in the crossing direction with the second electrode so as to form one unit, and the second electrode includes the first electrode The first barrier ribs formed so as to intersect with each other are separated in a line so as to face one unit of the pixel electrode, and the second barrier ribs are formed so as to be positioned between the pixel electrodes in one unit. It is characterized by being That.

  Further, an auxiliary electrode made of a material having a lower electrical resistance than the wiring electrode is formed on the wiring electrode.

  Further, the second partition wall is formed by being divided except for a portion facing the auxiliary electrode.

  The present invention relates to an organic EL panel that uses an organic EL element and is particularly driven passively. In an organic EL panel having a multi-matrix structure, it is possible to maintain a good appearance even when the usage time has elapsed.

  Hereinafter, the organic EL panel according to the present embodiment will be described. The organic EL panel has a basic configuration in which an organic layer having at least a light emitting layer is laminated between a first electrode and a second electrode formed on a light-transmitting glass substrate.

  FIG. 1 shows an electrode structure of the organic EL panel. The organic EL panel includes a pixel electrode 1a and a wiring electrode 1b, a signal electrode (first electrode) 1 serving as an anode, and a scanning electrode (second electrode) formed so as to intersect the signal electrode 1 and serving as a cathode. 2 and. In the organic EL panel, a light emitting pixel (organic EL element) is formed at an opposing (crossing) portion between the pixel electrode 1a and the scanning electrode 2, and a plurality of the light emitting pixels are arranged in a matrix to form a light emitting unit. Note that an insulating layer is formed below the scanning electrode 2 except for a portion that becomes a light emitting pixel, and a short circuit between the signal electrode 1 and the scanning electrode 2 is prevented. FIG. 2 is an enlarged view of a main part of the organic EL panel. An auxiliary electrode 3 is formed on the wiring electrode 1 b of the signal electrode 1. Further, the scanning electrodes 2 are separated and formed by first ribs (first partition walls) 4. In addition, second ribs (second partition walls) 5 are formed where the first ribs between the pixel electrodes 1a are not formed. FIG. 3 is a cross-sectional view of an essential part of the organic EL panel, 6 is the above-described insulating layer for preventing short circuit, 7 is an organic layer including at least a light emitting layer, and 8 is a glass substrate.

  The signal electrode 1 is formed in a plurality of lines and has a plurality of pixel electrodes 1a arranged in the column direction (crossing direction with the scanning electrode 2) and a wiring electrode 1b connected to the pixel electrode 1a. It is. The signal electrode 1 is formed so that a plurality of (two in the present embodiment) adjacent to each other in the column direction of the pixel electrodes 1a constitute one unit, and the pixel electrodes 1a in one unit are connected to different wiring electrodes 1b. ing. That is, the signal electrode 1 is formed so as to constitute one column of the light emitting pixels by two lines.

  The pixel electrode 1a is formed by forming a light-transmitting conductive material such as ITO (Indium Tin Oxide) in a layer shape on the glass substrate by a sputtering method or the like, and patterning it into a predetermined shape by, for example, a photolithography method. Is. In the present embodiment, each pixel electrode 1 a is formed in a substantially rectangular shape, and is arranged on the glass substrate 7 in a matrix.

  The wiring electrode 1b is made of the same material as the pixel electrode 1a and is formed together with the pixel electrode 1a. The wiring electrodes 1b are formed between the columns of the pixel electrodes 1a so as to intersect the scanning electrodes 2, and are alternately connected to the pixel electrodes 1a in each column of the pixel electrodes 1a. The wiring electrodes 1b are wired toward one side of the glass substrate and connected to the signal electrode side drive circuit 9. The signal electrode side drive circuit 9 supplies power to the signal electrode 1 so as to display a predetermined image in accordance with the sequential scanning of the scan electrodes 2 by the scan electrode side drive circuit 10 described later.

  The scanning electrode 2 is a metal having higher conductivity than the signal electrode 1 such as aluminum (Al), magnesium (Mg), cobalt (Co), lithium (Li), gold (Au), zinc (Zn), or an alloy thereof. The conductive conductive material is formed into a layer by a vapor deposition method or the like, and is formed separately into a plurality of lines by the first rib 4. Each scanning electrode 2 intersects with the signal electrode 1 and is formed so as to face one unit of the pixel electrode 1a in the column direction. Further, each scan electrode 2 is connected to the scan electrode side drive circuit 10. The scan electrode side drive circuit 10 sequentially scans the scan electrodes 2 at a predetermined duty ratio.

  The auxiliary electrode 3 is made of a material such as chromium (Cr), molybdenum (Mo), aluminum (Al), copper (Cu), or an alloy thereof having a lower electric resistance than the constituent material of the pixel electrode 1a by a method such as sputtering. It is formed in a layer and is patterned into a predetermined shape by, for example, a photolithography method. The auxiliary electrode 3 may be formed by forming a plurality of layers of different materials. Further, the auxiliary electrode 3 is divided and formed so as to exclude a portion facing the first rib 4. This is for preventing the ultraviolet rays irradiated when the first rib 4 is formed by the photolithography method from being reflected by the auxiliary electrode 3 so that the first rib 4 does not have a desired shape.

  The first rib 4 is formed by forming an insulating resin material in a line shape by a photolithography method in a direction intersecting with the signal electrode 1. The first rib 4 separates and forms the scanning electrode 2 so as to face one unit of the pixel electrode 1a in the column direction. Therefore, the first rib 4 for separating the scanning electrode 2 is not formed between the pixel electrodes 1a in one unit. In order to separate the scan electrodes 2 satisfactorily, it is desirable that the first ribs 4 are formed so as to have a reverse taper in cross section as shown in FIG.

  The second rib 5 is formed by forming an insulating resin material in a line shape in a direction intersecting with the signal electrode 1 by a photolithography method. The second rib 5 is formed at a position where the first rib 4 is not formed, that is, between the pixel electrodes 1a in one unit. The second rib 5 does not separate the scanning electrode 2. Further, the second rib 5 is formed by being divided so as to exclude a portion facing the auxiliary electrode 3.

  Such an organic EL panel has a so-called multiple matrix structure, and two rows of light emitting pixels are controlled to be turned on when the scanning electrode 2 performs one line scanning.

  In the organic EL panel of the present embodiment, by providing the second rib 5 so as to be positioned between the pixel electrodes 1a in one unit, the occurrence of dark frames can be made equal in all the light emitting pixels, Even if the usage time elapses, a good appearance can be maintained. Moreover, since the auxiliary electrode 3 does not oppose the second rib 5 by dividing the second rib 5 so as to exclude a portion facing the auxiliary electrode 3, the second rib 5 is formed in a good shape. Therefore, it is not necessary to increase the number of locations where the auxiliary electrode 3 is divided, and an increase in the wiring resistance of the signal electrode 1 can be suppressed.

  In this embodiment, two pixel electrodes 1a constitute one unit, and each pixel electrode 1a in one unit is connected to a different wiring electrode 1b. These pixel electrodes may constitute one unit. That is, a configuration in which three or more pixel electrodes connected to different wiring electrodes with respect to one line of the scanning electrodes are arranged to face each other may be used. The same effect can be obtained by applying the present invention to these configurations.

It is a general-view figure which shows the electrode structure of the organic electroluminescent panel which is embodiment of this invention. It is a principal part enlarged view of an organic electroluminescent panel same as the above. It is principal part sectional drawing of an organic electroluminescent panel same as the above.

Explanation of symbols

1 Signal electrode (first electrode)
1a Pixel electrode 1b Wiring electrode 2 Scan electrode (second electrode)
3 Auxiliary electrode 3a Width details 4 First rib (first partition)
5 Second rib (second partition)
6 Insulating layer 7 Organic layer 8 Glass substrate 9 Signal electrode side drive circuit 10 Scan electrode side drive circuit

Claims (3)

An organic EL device comprising an organic EL element formed by laminating an organic layer having at least a light emitting layer between a first electrode formed on a substrate and a second electrode formed so as to intersect the first electrode A panel,
The first electrode includes a plurality of pixel electrodes arranged in a crossing direction with the second electrode and wiring electrodes connected to the pixel electrodes, and the pixel electrodes connected to different wiring electrodes are It is formed so as to constitute one unit adjacent to the second electrode in the intersecting direction with the second electrode,
The second electrode is separated and formed in a line so as to face one unit of the pixel electrode by a first partition formed to intersect the first electrode,
2. An organic EL panel, wherein a second partition is formed so as to be positioned between the pixel electrodes in one unit. The organic EL panel according to claim 1, wherein an auxiliary electrode made of a material having a lower electric resistance than the wiring electrode is formed on the wiring electrode. 3. The organic EL panel according to claim 2, wherein the second partition wall is formed by being divided except for a portion facing the auxiliary electrode. 4.

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