JP2003168557A - Organic el panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL panel which has a large area of light- emitting part and in which fluctuation of the luminance of the light-emitting part is suppressed even in the case a large constant current is required, and degradation of display quality can be prevented. <P>SOLUTION: The organic EL panel comprises a laminated body in which organic layers having a luminous layer is clipped by a pair of electrodes of which at least one is translucent, a drawing-out part 15a which is provided to draw out from at least two positions of the transparent electrode (positive electrode) 2a, and a current drive source which is connected to the drawing-out part 15a and supplies a constant current to the above laminated body. <P>COPYRIGHT: (C)2003,JPO

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) panel driven based on a constant current from a current driving source.

[0002]

2. Description of the Related Art As shown in FIG. 6, an anode 2 made of a transparent conductive material such as indium oxide (ITO) on a transparent substrate 1, an organic layer having at least a light emitting layer (for example, a hole injection layer from the anode side, (It has a multi-layer structure in which a hole transport layer, an electron transport layer, an electron injection layer, etc. are laminated according to the light emitting layer)
An organic EL element A, which is a laminated body including a cathode 4 made of a metal conductive material such as 3 and aluminum (Al), is known, for example, from Japanese Patent Publication No. 6-32307. 5
Is an insulating layer for ensuring insulation between the anode 2 and the cathode 4. Further, 6 is a constant current circuit (current drive source) for obtaining a constant current for driving the organic EL element A, and 7 is, for example, for boosting the power supply voltage of the battery to generate a drive voltage for driving the organic EL element A. Power supply circuit.

Such an organic EL panel obtains predetermined light emission by applying a constant current supplied from the constant current circuit 6 to the organic EL element A through a single electrode lead portion. However, in a single organic EL element A having a large light emitting area (for example, a large segment display such as a digital display), the constant current supplied to the electrode lead portion also becomes large, so that the electrode lead portion There is a difference in the heat generation amount based on the constant current between the element located in the vicinity and the elements in the other parts.

[0004]

Accordingly, the organic EL device A
Has a brightness lowering characteristic that the brightness lowering time is faster when the temperature is higher. Therefore, the emission brightness varies among the single organic EL elements A due to the difference in the heat generation amount, and the display quality is deteriorated. There was a problem such as.

In view of the above problems, the present invention suppresses the variation in luminance at the light emitting portion and impairs the display quality even when the light emitting portion has a large area and a large constant current is required. It is an object of the present invention to provide an organic EL panel capable of preventing this.

[0006]

In order to solve the above-mentioned problems, the present invention provides a laminate in which an organic layer having a light-emitting layer is sandwiched between a pair of electrodes, at least one of which is transparent, and a transparent electrode. And a current drive source that is connected to the lead-out portion and supplies a constant current to the laminated body.

Also, at least two electrodes are provided from the transparent electrode.
One or more lead-out portions are drawn out and formed, and a current drive source is connected to each of the lead-out portions.

A laminated body in which at least one of the organic layers having a light emitting layer is sandwiched by a pair of translucent electrodes, and the laminated body is formed on the entire circumference or part of the periphery of the laminated body. A metal layer having a higher conductivity than the transparent electrode in contact with the transparent electrode, a lead portion provided so as to be pulled out from the metal layer, and a constant current connected to the lead portion and supplying a constant current to the laminate. And a current drive source.

Further, at least two lead portions are drawn out from the metal layer, and a current driving source is connected to each lead portion.

Further, the lead-out portion is formed by forming a wide area on the side of the laminated body that is wider than that on the side of the current drive source.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. The same or corresponding portions as those of the above-mentioned conventional technique are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 1 relates to a first embodiment of the present invention, in which an organic EL panel 10 is an organic EL element A (see FIG. 6).
It is a digital speedometer that is a display device for vehicles using.

As shown in FIG. 6, the groups 11 to 13 are organic EL elements in which an anode 2 which is a translucent electrode is formed separately, and an insulating layer 5, an organic layer 3 and a cathode 4 are sequentially laminated. The group 11 is divided into seven segments 11a to 11g, which are light emitting points arranged in a Japanese letter shape, and pseudo-displays the Arabic numerals "0" to "9". It is divided and formed similarly. Further, the group 13 pseudo-displays the Arabic numeral "1" by the segment 13a and the segment 13b. By arranging a plurality of groups 11 to 13 in the horizontal direction, a three-digit number from "0" to "199" can be displayed. The group 11 is at the lowest digit and the group 13 is at the highest digit.

Further, 14 is also a part of the organic EL element A and is a unit symbol portion for displaying the unit of speed "km / h", and this unit symbol portion 14 is also a light emitting portion.

FIG. 2 shows the electrical construction of a driving device for driving the organic EL panel 10. 20 is a sensor which outputs a pulse signal in accordance with the rotational speed of the wheel, and 30 is an output from the sensor 20 ( A counter for counting the number of pulses), a microcomputer 40 for calculating a traveling distance from the count number of the counter 30, and outputting a control signal so that the organic EL panel 10 which is a digital speedometer displays the calculation. A control unit 50, a power supply circuit 50 including an in-vehicle battery, a booster circuit, and the like 61 a power supply circuit 50
Constant current circuit (current drive source) 61 for obtaining a constant current from the
The constant current circuit unit 71 having a to 61 g, 71 is a constant current circuit unit 6 to the segments 11a to 11g composed of the organic EL element A that displays a predetermined number based on an instruction from the control unit 40.
1 is a switch unit having switches 71a to 71g for supplying or blocking the current from the constant current circuits 61a to 61g.

Although FIG. 2 shows only the group 11 displaying the least significant digit and omits the other groups 12 and 13, the constant current circuit section 61 and the switch section 71 are also included in the other groups 12 and 13. Needless to say, the components corresponding to are connected and the predetermined numbers are displayed based on the instruction from the control unit 40.

Further, the constant current circuit 62 of the constant current circuit unit 62
“A” is connected to the unit symbol portion 14, and the unit symbol portion 14 displays the unit “km / h” of the speedometer when a constant current is supplied from the constant current circuit 62a.

FIG. 3 shows the anodes 2 forming the group 11.

The lead-out portion 15a is formed by drawing out from two portions of the anode 2a having the shape of the segment 11a, and the constant current circuit 61 is formed by a single wiring portion 15b.
It is electrically connected to a. "Drawer formation" here
May be formed integrally with the anode 2a, or the extraction portion 15a may be provided exclusively for the anode 2a.
It may be bonded to a. In addition, the drawer 1
5a has a wide area B on the side of the anode 2a which is wider than that on the side of the constant current circuit 61a. In addition, the segment 11a
In, the lead portion 15a and the wiring portion 15b are non-visible areas covered with the insulating layer 5, and the inside of the dotted line of the anode 2a is a light emitting portion. Although only the anode 2a in the segment 11a is shown in FIG. 3 and the other anodes 2b to 2g are omitted, the other anodes 2b to 2g are also the anode 2a.
Same configuration as. In the above description, the group 11
However, in the organic EL panel 10, the other groups 12 and 13 and the unit symbol portion 14 have the same configuration as that of the group 11.

In such an organic EL panel 10, the extraction portion 15a is formed from two positions of the anode 2a in the segment 11a.
Is formed and the anode 2a and the constant current circuit 61a are connected by a single wiring portion 15b, so that the constant current circuits 61b to 6b, which are current drive sources, are formed.
Since the constant current output from 1 g can be dispersed and supplied to the anodes of the single segment 11a, it is possible to suppress the locally concentrated heat generation in the organic EL element A, suppress the variation in the emission brightness, and display quality. It is possible to prevent the damage.

Further, in such an organic EL panel 10, a wide area B having a width wider than that of the constant current circuit side is formed on the anode side of the lead portion 15a, so that the constant current output from the constant current circuit can be efficiently generated. Organic E as it can be supplied
It is possible to further suppress the locally concentrated heat generation in the L element A.

In the first embodiment of the present invention, the lead-out portion 15a is formed by drawing out from two portions of the anode 2a, but in the present invention, at least the place where the lead-out portion is drawn out is formed. It may be two or more places.

FIGS. 4 and 5 relate to the second and third embodiments of the present invention, and the same or corresponding portions as those of the above-mentioned conventional technique or the first embodiment are designated by the same reference numerals. The detailed explanation is omitted.

FIG. 4 shows the anodes 2 forming the group 11 in the organic EL panel 10 according to the second embodiment of the present invention.

First and second lead portions 16a, 17a
Are formed by being drawn out respectively from two positions of the anode 2h that shape the shape of the segment 11a, and are the first and second current driving sources by the first and second wiring portions 16b and 17b, respectively. It is electrically connected to a second constant current circuit (not shown). Further, the first and second lead portions 16a and 17a are provided on the side of the anode 2a, respectively.
A wide area B having a width wider than that of the second constant current circuit side is provided. In the segment 11a, the first and second lead portions 16a and 17a and the first and second wiring portions 16b and 17b are non-visual areas covered with the insulating layer 5, and the inside of the dotted line of the anode 2h serves as a light emitting portion. Become. Although FIG. 4 shows only the anode 2h in the segment 11a and omits the other anodes 2i to 2n, the other anodes 2i to 2n have the same configuration as the anode 2h. Further, although the group 11 has been described in the above description, the organic EL panel 10 has the same configuration as the other groups 12, 13 and the unit symbol portion 14.

In such an organic EL panel 10, the first and second lead portions 16a and 17a are drawn from the anode 2h, and the first and second wiring portions 16b and 17b are used to form the first and second lead portions, respectively. When a plurality of current drive sources are connected to one light emitting point by connecting to the constant current circuit of, the constant current output from the first and second constant current circuits which are the current drive sources is Single segment 1
Since it can be dispersed and supplied to the anode of 1a, it is possible to suppress the heat generation that is partially concentrated in the organic EL element A, suppress the variation in the emission brightness, and prevent the display quality from being impaired.

The second embodiment of the present invention is the anode 2
The first and second lead portions 16a and 17a are drawn out from h, and the first and second wiring portions 16b and 17 are formed.
Although it is configured to be connected to the first and second constant current circuits respectively by b, in the present invention, the lead-out portion formed at one light emitting point and the current driving source connected to one light emitting point The number is not limited to the second embodiment of the present invention.

Further, in the present invention, the first lead portion 16a is formed by branching from at least two locations of the anode 2h, and the second lead portion 17 is formed.
The configuration may be such that a is branched and formed from at least two locations different from the first lead portion 16a of the anode 2h.

FIG. 5 shows the anodes 2 forming the group 11 in the organic EL panel 10 according to the third embodiment of the present invention.

The metal layer 18a is formed on the entire circumference of the anode 2o forming the segment 11a and has a portion overlapping the anode 2o so as to be in contact with the anode 2o. The metal layer 18a has a conductivity higher than that of the anode 2o. Made of good metal conductive material.

The lead portion 19a is formed by being drawn from the metal layer 18a and is electrically connected to the constant current circuit 61a by the wiring portion 19b. The lead-out portion 19a is provided with a wide area B on the side of the anode 2o that is wider than that on the side of the constant current circuit 61a. In addition, segment 11
In a, the metal layer 18a, the lead portion 19a, and the wiring portion 19b are non-visual areas covered with the insulating layer 5, and the inside of the dotted line of the anode 2o is a light emitting portion. Note that, in FIG. 5, only the anode 2o in the segment 11a is shown and the other anodes 2p to 2u are omitted, but the other anode 2p.
The same structure as that of the anode 2o is used also for 2u. Also,
Although the group 11 has been described in the above description, the organic E
The L panel 10 has the same configuration as the group 11 with respect to the other groups 12 and 13 and the unit symbol portion 14.

In such an organic EL panel 10, a metal layer 18a having a conductivity higher than that of the anode 2o is formed on the entire circumference of the anode 2o so as to be in contact with the anode 2o, and a lead portion 19a is drawn from the metal layer 18a. The wiring portion 19b is connected to the constant current circuit 61a which is the current driving source, so that the constant current circuit 61a which is the current driving source is connected.
The constant current output from the anode 2o passes through the metal layer 18a.
Since the constant current supplied to the anode 2a can be dispersed all around the anode 2o by being supplied to the organic EL,
It is possible to suppress heat that is partially concentrated in the element A, suppress variations in light emission luminance, and prevent deterioration of display quality.

In the third embodiment of the present invention, the lead-out portion 19a is drawn out from one location of the metal layer 18a. However, the lead-out portion 19a is formed in the metal layer 18a.
Alternatively, the structure may be formed by drawing out from two or more places.

In the third embodiment of the present invention, one lead portion 19a is drawn from the metal layer 18a. However, the present invention is based on the metal layer 18a.
The second lead portion is formed by pulling out the first lead portion,
The second wiring portion may be connected to the first and second current drive sources, respectively.

[0035]

INDUSTRIAL APPLICABILITY The present invention is an organic EL (electroluminescence) driven by a constant current from a current driving source.
It is related to the panel, the area of the light emitting part is wide,
Even when a large constant current is required, it is possible to prevent the luminance from varying in the light emitting portion and prevent the display quality from being impaired.

[Brief description of drawings]

FIG. 1 is a diagram showing a display form of an organic EL panel which is a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing an electrical configuration of a driving device of the above organic EL panel.

FIG. 3 is a diagram showing an anode in the above organic EL panel.

FIG. 4 is a diagram showing an anode in an organic EL panel that is a second embodiment of the present invention.

FIG. 5 is a diagram showing an anode in an organic EL panel which is a third embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view showing the structure of an organic EL element.

[Explanation of symbols]

A organic EL device B Wide area 1 substrate 2,2a-2u Anode 3 organic layers 4 cathode 5 insulating layers 6 constant current circuit (current drive source) 7 Power circuit 10 Organic EL panel 11-13 groups 11a to 11g segment (light emitting point) 15a, 19a Drawer 15b, 19b wiring section 16a First drawer part 16b First wiring part 17a Second drawer part 17b Second wiring section 18a metal layer 14 Unit symbol part (light emitting part) 61,62 constant current drive unit 61a to 61g, 62a constant current circuit (current drive source)

Claims (5)

[Claims] 1. A laminate in which an organic layer having a light emitting layer is sandwiched between a pair of electrodes, at least one of which is translucent,
An organic EL device comprising: a lead-out portion provided so as to lead out from at least two or more transparent electrodes; and a current drive source connected to the lead-out portion and supplying a constant current to the laminate. panel. 2. The organic EL panel according to claim 1, wherein at least two lead portions are drawn out from the transparent electrode and a current driving source is connected to each lead portion. 3. A laminate in which an organic layer having a light emitting layer is sandwiched between a pair of electrodes, at least one of which is translucent,
A metal layer which is formed on the entire circumference or a part of the periphery of the laminate and has a conductivity higher than that of a transparent electrode that is in contact with the transparent electrode of the laminate, and is provided so as to be drawn from the metal layer. An organic EL panel comprising: a lead portion and a current drive source connected to the lead portion and supplying a constant current to the laminate. 4. The organic EL panel according to claim 3, wherein at least two lead portions are drawn out from the metal layer, and a current driving source is connected to each lead portion. 5. The organic material according to claim 1, wherein the lead-out portion is formed with a wide area having a width wider than that of the current drive source side on the laminate side. EL panel.