JP2001185365A - Organic EL display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL display element capable of suppressing a voltage drop in a current path on the upstream side in a current flow direction when a drive current is supplied to transparent anode portions connected in series to each other. I do. SOLUTION: This dot matrix drive type organic EL is provided.
In the display element, a metal grid 21 made of a low-resistance metal material such as chromium is provided on each transparent anode section 13 constituting each pixel section 11 of the anode pattern 3. Further, the wiring portion 15 of the anode pattern 3 is made of a transparent wiring layer 22 formed of the same transparent conductive material as the transparent anode portion 13.
And a light-shielding metal thin film 23 formed of the same low-resistance metal material as the metal grid 21 on the transparent wiring layer 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL (electroluminescence) display element, and more particularly to a structure of an electrode thereof.

[0002]

2. Description of the Related Art FIG. 7 is a view showing an electrode structure of a conventional dot matrix drive type organic EL display element, and FIG. 8 is a sectional view of the organic EL display element. As shown in FIG. 7 and FIG. 8, this organic EL display element includes a transparent substrate 1 made of a glass substrate or the like, and ITO (longitudinally or vertically) extending parallel to each other on the transparent substrate 1. A plurality of anode patterns 3 made of a transparent conductive material such as indium tin oxide); a light emitting layer 5 containing an organic compound provided on the transparent substrate 1 so as to cover the anode patterns 3; On the layer 5, there are provided a plurality of cathode patterns 7 made of a metal film or the like extending in parallel with each other in the vertical direction (or the horizontal direction) perpendicular to the anode pattern 3. An insulating film 9 is provided between each of the cathode patterns 7 so as to divide the light emitting layer 5. Also, the luminous body layer 5 has 2
It comprises at least one organic compound layer, and has, for example, a hole transport layer (buffer layer) provided on the anode side and an electron transport layer (light emitting layer) provided on the cathode side.

[0003] In the organic EL display element having such a configuration, pixel portions (hatched portions in FIG. 7) arranged in a matrix in the vertical and horizontal directions are formed by respective intersections of the anode pattern 3 and the cathode pattern 7 (hatched portions in FIG. 7). A light emitting portion 11 is formed. Each pixel section 11 is driven by selectively applying a drive voltage to the anode pattern 3 to which the pixel section 11 to be driven (lighted) belongs from among the plurality of anode patterns 3, and the plurality of cathode patterns 7. This is performed by selectively connecting the cathode pattern 3 to which the pixel unit 11 to be driven belongs to the ground. When each pixel unit 11 is driven to display a predetermined image, for example, one of the plurality of cathode patterns 7 is connected to the ground,
The driving voltage is applied to the anode pattern 3 of the plurality of anode patterns 3 to which the pixel unit 11 constituting the display image belongs at each minute time while the cathode pattern 7 connected to the ground is sequentially switched at high speed every minute time. Is applied to display an image.

That is, in such an organic EL display element, the transparent anode sections 13 constituting each pixel section 11 of the anode pattern 3 are connected in series by a wiring section 15 which is a connecting section between the respective transparent anode sections 13. The driving current is supplied to each transparent anode section 13 via the transparent anode section 13 and the wiring section 15 on the upstream side in the current flow direction of each transparent anode section 13. .

[0005]

However, in the above-mentioned conventional organic EL display element, since the transparent anode portion 13 and the wiring portion 15 are made of a transparent conductive material such as ITO having a relatively high resistance value, the series connection is not possible. Transparent anode 13 connected
There is a problem that the voltage drop due to the wiring resistance in the transparent anode portion 13 and the wiring portion 15 on the upstream side in the current flow direction when the driving current is supplied to the device is large. In contrast, conventional organic E
In the L display element, by setting the line width of the anode pattern 3 to be large, voltage drop due to wiring resistance in the transparent electrode portion 13 and the wiring portion 15 is suppressed. And the high definition of the pixel portion 11 is hindered.

[0006] Here, a dot matrix drive type organic EL display element has been described as an example of an organic EL display element having a plurality of transparent anode sections connected in series to each other by a wiring section. Organic EL having a plurality of transparent anode parts formed of a transparent conductive material
If it is a display element, a segment drive type organic EL display element and the like have the same problem.

[0007] In view of the above problems, the present invention provides an organic light emitting device that can suppress a voltage drop in a current path on the upstream side in a current flowing direction when a driving current is supplied to transparent anode portions connected in series to each other. An object is to provide an EL display element.

[0008]

The technical means for achieving the above object is that a plurality of transparent anode portions, which are disposed on a transparent substrate and are made of a transparent conductive material constituting a light emitting portion, are connected in series with each other by a wiring portion. An organic EL display element which is connected to a transparent electrode portion, and a driving current is supplied to the respective transparent anode portions on the downstream side in a current flow direction through the wiring portion and the respective transparent anode portions. A metal grid made of a low-resistance metal material is provided on the anode so as to cover the surface of the transparent anode in a grid.

Preferably, the wiring portion includes a transparent wiring layer formed of a transparent conductive material on the transparent substrate, and a light-shielding metal thin film formed of a low-resistance metal material on the transparent wiring layer. Good to have.

Preferably, the wiring portion is formed of a light-shielding metal thin film formed of a low-resistance metal material on the transparent substrate.

Further, preferably, the metal grid is provided in a parallel grid or a matrix grid.

Preferably, the organic EL display device is a dot matrix drive type organic EL display device,
The light-emitting portion is constituted by a plurality of anode patterns and a plurality of intersections of a plurality of cathode patterns extending vertically and horizontally so as to be orthogonal to each other across a light-emitting body layer containing an organic compound, the anode It is preferable that a portion of the pattern located at each of the intersections is the transparent anode portion, and a portion of each of the anode patterns that is not located at each of the intersections is the wiring portion.

Further preferably, the organic EL display element is a segment drive type organic EL display element, and a cathode portion disposed opposite to each of the transparent anode portions with a light emitting layer containing an organic compound interposed therebetween. It is preferable that each of the transparent anode portions connected in series via the wiring portion is individually provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> FIG. 1 shows a dot matrix drive type organic EL according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an electrode structure of a display element, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 is an enlarged cross-sectional view of a main part of FIG. The organic EL display element according to the present embodiment has the same configuration as the above-described organic EL display element shown in FIGS. 7 and 8 except for the structure of the anode pattern 3. The same reference numerals are given and the description is omitted.

In the organic EL display device according to this embodiment,
As shown in FIGS. 1 and 3, the surface of the transparent anode section 13 is placed in the longitudinal direction of the anode pattern 3 on each transparent anode section 13 made of a transparent conductive material such as ITO constituting each pixel section 11 of the anode pattern 3. A metal grid 21 made of a low-resistance metal material such as chromium is provided so as to partially cover a parallel grid along the (current flow direction). Here, the metal lattice 21 is provided so as to extend between two adjacent wiring portions 15 with each transparent anode portion 13 interposed therebetween. Thereby, the resistance value of each transparent anode portion 13 is largely suppressed.

Here, the arrangement conditions such as the line width and the number of the thin metal wires 21a constituting the metal grid 21 are determined such that the shade of the thin metal wires 21a is visually recognized when the pixel portion 11 emits light, It is necessary to make settings so that the brightness does not decrease.

Further, in the organic EL display element according to the present embodiment, a wiring portion 15 (in FIG. 1, a hatching in a satin-like pattern in FIG. 1) connecting the respective transparent anode portions 13 which are portions other than the transparent anode portion 13 of the anode pattern 3. 3, a transparent wiring layer 22 formed on the transparent substrate 1 with the same transparent conductive material as the transparent anode section 13 as shown in FIG. 3, and the same as the metal grid 21 on the transparent wiring layer 22. And a light-shielding metal thin film 23 formed of a low-resistance metal material. Here, the metal thin film 23 is provided in a planar shape so as to cover the entire surface of the transparent wiring layer 22. Then, the resistance value of the wiring portion 15 is largely suppressed by the metal thin film 23.

Such a metal grid 21 and a metal thin film 2
The formation of 3 is preferably performed simultaneously by vapor deposition, printing, etching or the like.

As described above, according to the present embodiment, when the drive current is supplied to the transparent anode sections 13 connected in series with each other, the current path (upstream side) of each transparent anode section 13 in the current flow direction is provided. Voltage drop in the transparent anode section 13 and the wiring section 15) can be largely suppressed, and as a result, the anode pattern 3
, The anode pattern 3 can be made thinner, and the pixel portion 11 can be made more precise.

Since the metal grid 21 provided on the transparent anode section 13 partially covers the surface of the transparent anode section 13 in a grid shape, the metal grid 21 substantially hinders the light emission of each pixel section 11. Never.

The metal thin film 2 used for the wiring portion 15
Since 3 has a light-shielding property, it is possible to prevent the light from the pixel section 11 from leaking to the display surface side through the wiring section 15 and deteriorating the display quality.

<Second Embodiment> FIG. 4 is a view showing an electrode structure of a segment drive type organic EL display element according to a second embodiment of the present invention, and FIG. FIG.

The organic EL display element according to the present embodiment is a segment drive type organic EL display element, and includes first to seventh seven segments (light emitting portions) 31a to 31 respectively.
g, 3a with 33a-33g, 35a-35g
It has segment display units (display units) 31, 33, 35, and each of the 7-segment display units 31, 33, 35
It is possible to display numbers from 9 to 9.

In the organic EL display device having such a structure,
Each segment 31a-31 is placed on a transparent substrate (not shown).
g, 33a-33g, ITO constituting 35a-35g
And a plurality of transparent anode portions 13 made of a transparent conductive material such as 7-segment display portions 31, 33, 3
5, corresponding segments 31a to 31g, 33
A plurality of wiring portions 15 are provided to connect the three transparent anode portions 13 constituting a to 33g and 35a to 35g in series with each other.

Thus, each 7-segment display unit 3
1, 33, 35 segments 31a to 31g, 33a
Transparent anode part 13 which constitutes each of
Is supplied with a drive current via the transparent electrode portion 13 and the wiring portion 15 on the upstream side of the transparent anode portion 13 in the current flow direction. For example, the transparent anode unit 1 constituting the first segment 35a of the seven-segment display unit 35
3 includes first segments 31a, 33a of 7-segment display units 31, 33 located on the upstream side in the current flow direction.
The driving current is supplied via the transparent anode part 13 and the wiring part 15 connecting them.

On the transparent substrate provided with the transparent anode section 13 and the wiring section 15, a 7-segment display section 3 is provided.
Areas 41a, 41b, 41c corresponding to 1, 33, 35
Is provided, except for the insulating film 41.
From above, a light-emitting layer (not shown) having the same configuration as the light-emitting layer 5 of FIG. 8 described above is provided.
Each of the seven segment display units 31, 33, and 35 is opposed to the seven transparent anode units 13.
Cathode film (cathode part) 4 made of metal film etc. for each 33, 35
3, 45, 47 are provided in a plane.

Here, also in this embodiment, each wiring portion 15 has the same configuration as the wiring portion 15 according to the first embodiment, and at least a part of the plurality of transparent anode portions 13. As in the case of the transparent anode 13 according to the first embodiment, the transparent anode 13 (here, the length of the current flowing direction is long and the resistance of the transparent anode 13 is equal to or more than a predetermined value) is provided on the transparent anode 13 as shown in FIG.
As shown in FIG. 1, a metal grid 21 made of a low-resistance metal material such as chromium is provided so as to partially cover the surface of the transparent anode section 13 in a parallel grid shape along the direction of current flow. The metal grid 21 is provided so as to extend between two adjacent wiring portions 15 with each transparent anode portion 13 interposed therebetween.

Each segment 31a-31g, 33a-3
3g and 35a to 35g are driven by the segments 31a to 31g, 33a to 33g, and 35a to 3g to be driven.
A drive current is supplied to each of the transparent anode portions 13 constituting 5 g via the transparent anode portion 13 and the wiring portion 15 on the upstream side in the current flow direction, and the three cathode films 43, 45, and 47 are provided.
Of the segments 31a to 31 to be driven
g, 33a-33g, and cathode films 43, 4 corresponding to the 7-segment display units 31, 33, 35 to which 35a-35g belong.
5, 47 are selectively connected to the ground.

The three 7-segment display sections 31,
In the case of performing a predetermined numerical display by 33, 35, for example, one of the three cathode films 43, 45, 47 is connected to the ground, and one of the three cathode films 43, 45, 47 is connected to the ground. Cathode films 43, 45, 47
Are sequentially switched at high speed for each minute time, and the segments 31a to 31 to be turned on for each minute time are changed.
g, 33a to 33g, and 35a to 35g, a numerical value is displayed by applying a drive voltage to the transparent anode section 13.

As described above, also in the present embodiment, when the drive current is supplied to the respective transparent anode sections 13 connected in series with each other, the current path (transparent side) on the upstream side in the current flowing direction of each transparent anode section 13 is used. The voltage drop at the anode section 13 and the wiring section 15) can be largely suppressed.

Since the metal grid 21 provided on the transparent anode portion 13 partially covers the surface of the transparent anode portion 13 in a grid shape, the metal grid 21 substantially covers each segment 31a.
It does not hinder the emission of light of up to 31 g, 33 a to 33 g, and 35 a to 35 g.

Further, the wiring portion 15 can be made thinner while the resistance value of the wiring portion 15 is suppressed. As a result, the space for disposing the wiring portion 15 on the transparent substrate can be reduced, and the organic EL display element can be manufactured. The size can be reduced.

Further, since the metal thin film 23 used for the wiring section 15 has a light shielding property, each of the segments 31a to 31a
Light from 31g, 33a to 33g, and 35a to 35g can be prevented from leaking to the display surface side through the wiring portion 15 and deteriorating the display quality.

<Modification> In each of the above embodiments,
Although the parallel anode-shaped metal grids 21 are provided in the respective transparent anode portions 13, the matrix grid-shaped metal grids 21 may be provided as shown in FIG. In this case, the metal grid 21 is inclined with respect to the current flow direction as shown in FIG. 6 in order to reduce the arrangement length of each metal thin wire 21a constituting the metal grid 21 and reduce the resistance value. It is preferable to provide them in an oblique lattice (diamond matrix lattice).

Further, in each of the above-described embodiments, each of the disposing units 1
5 is a transparent wiring layer 22 and a metal thin film 2 provided thereon.
3, each wiring section 15 may be constituted only by the metal thin film 23.

[0036]

According to the first to sixth aspects of the present invention, the resistance value of each transparent anode portion can be largely suppressed by the metal grid made of a low-resistance metal material provided on the transparent anode portion. As a result, when a drive current is supplied to each transparent anode section, a voltage drop in the current path (transparent anode section) on the upstream side in the current flow direction of each transparent anode section can be significantly suppressed.

According to the second aspect of the present invention, the wiring portion is made of a transparent conductive material, and a light-shielding metal thin film formed on the transparent wiring layer by a low-resistance metal material. Therefore, the resistance value of the wiring portion can be largely suppressed by the metal thin film, and as a result, when the driving current is supplied to each transparent anode portion, the current flowing direction upstream of each transparent anode portion is The wiring portion can be made thinner while suppressing a voltage drop in the current path (wiring portion) on the side.

Further, since the metal thin film used for the wiring portion has a light shielding property, it is possible to prevent the light from the light emitting portion from leaking to the display surface side through the wiring portion and deteriorating the display quality.

According to the third aspect of the present invention, since the wiring portion is formed of a light-shielding metal thin film formed of a low-resistance metal material, the resistance of the wiring portion can be significantly suppressed. As a result, when a drive current is supplied to each transparent anode portion, the voltage drop in the current path (wiring portion) on the upstream side in the current flow direction of each transparent anode portion is suppressed, and the thin wires of the wiring portion are suppressed. Can be achieved.

Further, since the metal thin film used for the wiring portion has a light-shielding property, it is possible to prevent the light from the light emitting portion from leaking to the display surface side through the wiring portion and deteriorating the display quality.

[Brief description of the drawings]

FIG. 1 is a diagram showing an electrode structure of a dot matrix drive type organic EL display element according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is an enlarged sectional view of a main part of FIG.

FIG. 4 is a diagram showing an electrode structure of a segment drive type organic EL display element according to a second embodiment of the present invention.

FIG. 5 is an enlarged view of a portion indicated by reference numeral A in FIG.

FIG. 6 is a diagram showing a modification of the configuration of FIG. 2;

FIG. 7 is a diagram showing an electrode structure of a conventional dot matrix drive type organic EL display element.

FIG. 8 is a sectional view of the organic EL display element of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transparent substrate 3 Anode pattern 5 Light emitting layer 7 Cathode pattern 9 Insulating film 11 Pixel part 13 Transparent anode part 15 Wiring part 21 Metal grid 22 Transparent wiring layer 23 Metal thin film 33a-33g, 35a-35g, 37a-37g Segment 41 Insulation Membrane 43, 45, 47 Cathode membrane

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Nobuyuki Minami 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi F-term in Harness Research Institute, Inc. (reference) 3K007 AB00 AB05 BA06 CA01 CB01 CB04 DA00 DB03 EB00 FA01

Claims (6)

[Claims] 1. A plurality of transparent anode portions, which are disposed on a transparent substrate and are made of a transparent conductive material constituting a light-emitting portion, are connected in series by a wiring portion, and are connected via the wiring portion and each of the transparent anode portions. An organic EL display element in which a drive current is supplied to each of the transparent anode portions on the downstream side in a current flow direction, wherein a surface of the transparent anode portion is covered in a grid on the transparent anode portion. An organic EL display element provided with a metal grid made of a low-resistance metal material. 2. The wiring section includes: a transparent wiring layer formed on the transparent substrate by a transparent conductive material; and a light-shielding metal thin film formed by a low-resistance metal material on the transparent wiring layer. The organic EL display element according to claim 1, wherein 3. The organic EL display device according to claim 1, wherein the wiring portion is formed of a light-shielding metal thin film formed of a low-resistance metal material on the transparent substrate. 4. The organic EL display device according to claim 1, wherein the metal grids are provided in a parallel grid shape or a matrix grid shape. 5. The organic EL display element is a dot matrix drive type organic EL display element, and the light emitting portions are vertically and horizontally extended so as to be orthogonal to each other with a light emitting layer containing an organic compound interposed therebetween. A plurality of anode patterns and a plurality of cathode patterns each constituted by the intersection, the portion of each anode pattern located at each intersection,
2. The wiring part, wherein the transparent anode part is a part that is not located at each of the intersections of the anode patterns.
5. The organic EL display device according to any one of items 1 to 4. 6. The organic EL display device is a segment drive type organic EL display device, wherein a cathode portion opposed to each of the transparent anode portions with a light-emitting layer containing an organic compound interposed therebetween is provided with the wiring. The organic EL display element according to claim 1, wherein the organic EL display element is provided separately for each of the transparent anode sections connected in series via a section.