JP2006338987A - Organic el display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display capable of performing display having sufficient visibility even in a bright environment, with thin and compact size. <P>SOLUTION: The organic EL display 1 which displays image information and letter information comprises a plurality of positive electrodes 3 arranged in a horizontal direction on a common transparent substrate 2, a plurality of negative electrodes 4 having as one set a first negative electrode 41 and a second negative electrode 42 which have a prescribed spacing from the plurality of positive electrodes 3 and are arranged in a direction crossing at right angles the plurality of positive electrodes 3, an organic EL layer 7 which is formed at the crossing part 7 of the plurality of positive electrodes 3 and the first negative electrode 41 and between these, and a spacer 5 which is provided at the crossing part of the plurality of positive electrodes 3 and the second negative electrode 42 and between these. The second negative electrode 42 is made of an elastic body which moves up and down in perpendicular direction against the plurality of positive electrodes 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic EL display (organic electroluminescence display) with improved outdoor visibility.

  Since organic EL elements have high-speed response and can emit light with low power consumption without dependence on the viewing angle, application to display devices such as portable terminal devices and personal computers as a display element has been studied. In-vehicle audio display panels have been put to practical use as area color display elements in which monocolors are partially combined.

  A high-performance organic EL display that emits light with high brightness at low voltage because full-color display is possible by combining display elements corresponding to red (R), green (G), and blue (B) organic EL elements. Various studies have been made.

Such an organic EL display is described in Patent Document 1.
That is, Patent Document 1 discloses an organic EL display unit that enables high-definition display with excellent visibility in a mobile terminal electronic device such as a mobile phone, and a transflective or reflective type that can reduce power consumption. It is described that by providing a liquid crystal display unit of a type, power consumption can be reduced and a display device can be selectively used according to the type and situation of information.
JP 2002-304136 A

However, since the organic EL element used in the organic EL display is a self-luminous element, there is a problem that sufficient contrast cannot be obtained in a bright environment and visibility is extremely lowered.
In addition, as mobile phones, display panels are provided on both sides of a display unit, and one display panel displays a message with high message quality and the other displays image information. Since the display panel requires a pair of electrodes for displaying information, it is necessary to provide four electrodes in the thickness direction. For this reason, there has been a problem that the overall thickness is increased, and it is thin and cannot be made compact.

  Therefore, the present invention is proposed in view of the above-described problems, and provides a thin and compact organic EL display that can perform display with sufficient visibility even in a bright environment. With the goal.

  The present invention relates to an organic EL display for displaying image information and character information, and a plurality of anodes arranged in a horizontal direction on a common transparent substrate, the plurality of anodes having a predetermined interval, and the plurality of anodes The first cathode and the second cathode arranged in a direction orthogonal to the plurality of cathodes, and at the intersection of the plurality of anodes and the first cathode, and formed between them An organic EL layer; and a spacer provided at an intersection of the plurality of anodes and the second cathode and provided therebetween, wherein the second cathode is perpendicular to the plurality of anodes. An organic EL display comprising an elastic body that moves up and down in a direction is provided.

  According to the present invention, a plurality of anodes arranged in a horizontal direction on a common transparent substrate, and a first cathode arranged at a predetermined interval from the plurality of anodes and orthogonal to the plurality of anodes A plurality of cathodes, each of which includes a plurality of cathodes and a second cathode, an organic EL layer formed at and between the plurality of anodes and the first cathode, the plurality of anodes, Since the second cathode is made of an elastic body that moves up and down in the vertical direction with respect to the plurality of anodes, at the intersection with the second cathode and between the spacers, Display with sufficient visibility can be performed even in a bright environment, and the display can be made thin and compact.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing an organic EL display according to an embodiment of the present invention.
2 is a cross-sectional view taken along the line AA in FIG. FIG. 3 is a BB cross-sectional view of FIG.

  As shown in FIG. 1, the organic EL display 1 according to the embodiment of the present invention includes a plurality of anodes 3 arranged in a horizontal direction on a common transparent substrate 2, and a plurality of anodes 3 in a direction perpendicular to the plurality of anodes 3. The cathode 4 is arranged. The plurality of cathodes 4 includes a pair of first cathode 41 and second cathode 42. As shown in FIG. 2, the organic EL layer 5 is formed in a matrix at the intersection of the plurality of anodes 3 and the first cathode 41 and between them. In addition, as shown in FIG. 3, the spacer 5 is formed at the intersection of the plurality of anodes 3 and the second cathode 42 and between them, and the plurality of anodes 3 and the second cathode 42 are connected to each other. There is a gap 6 between them.

The common transparent substrate 2, the anode 3, the first cathode 41, and the organic EL layer 7 constitute an organic EL element 8.
The organic EL layer 7 has a configuration in which a hole transport layer 71, a light emitting layer 72, and an electron transport layer 73 are sequentially stacked on the plurality of anodes 3.

The anode 3 is made of a light transmissive electrode having a work function of about 5 eV, and for example, indium-tin oxide (hereinafter referred to as ITO) can be used.
As the hole transport layer 71, for example, an aryldiamine compound (hereinafter referred to as TPD) can be used.

The light-emitting layer 72 can be widely used from a high-molecular material having fluorescence to a low-molecular material and a metal complex. For example, a tris (8-quinolinol) aluminum organometallic complex (hereinafter simply referred to as Alq3) is used. it can. Alq3 can also be used as an electron transport layer because of its electron transport property.
As the cathode 41, a silver-magnesium alloy having a small work function can be used.

The anode 3, the second cathode 42 that moves up and down, and the spacer 5 constitute a MEMS (Micro Electro Mechanical Systems) element 9. The second cathode 42 is made of an elastic body that moves up and down in the vertical direction with respect to the plurality of anodes 3 by a driving unit (not shown).
The MEMS element 9 forms a Fizeau interferometer with the anode 3 and the second cathode 42, and irradiates white light from the transparent substrate 2 side, and between the anode 3 and the second cathode 42 corresponding to the thickness of the spacer 5. It is strengthened by the interference in the above, and only the emitted color emitted from the common transparent substrate 2 side can be taken out and displayed.
Therefore, the thickness of the spacer 5 is regularly changed so that interference light of the three primary colors can be obtained in the organic EL display 1 so that color display can be performed.

Next, this operation will be described.
First, the case where the some organic EL element 8 is operated is demonstrated.
A plurality of anodes 3 and first cathodes 41 are sequentially scanned by a drive circuit (not shown), and a current is passed through the organic EL layer 7 so that the emission color corresponding to the light emitting layer of the organic EL layer 7 is emitted from the common transparent substrate 2 side. The characters and image information can be displayed after being taken out. For example, the voltage applied to each electrode is +5 V for the anode 3 and the ground potential for the first cathode 41.

Next, a case where the MEMS element 9 is operated will be described.
When a plurality of anodes 3 and the second cathode 42 are sequentially scanned by a drive circuit (not shown) and an attractive force acts between the anode 3 and the second cathode 42, the gap 6 does not exist, so the transparent substrate 2 Even if light is irradiated from the side, the light is only reflected by the second cathode 42 and returned, so there is no light emission and a black mode is set. When a repulsive force acts between the anode 3 and the second cathode 42, the interference light corresponding to the gap 6 determined by the thickness of the spacer 5 can be extracted, so that the emission color can be obtained.
A color display is obtained by selecting the MEMS element 9 from which three primary color lights can be obtained.

  When an attractive force is applied between the anode 3 and the second cathode 42, for example, the anode 3 is + 5V, the second cathode 42 is 0V, and a repulsive force is applied between the anode 3 and the second cathode 42. In the case of the action, the anode 3 is + 5V, and the second cathode 42 is + 5V.

  As described above, the plurality of anodes 3 and the first cathode 41 or the second cathode 42 are sequentially scanned to selectively display the organic EL element 8 or the MEMS element 9 and to extract information from the common transparent substrate 2. Therefore, a compact and thin organic EL display can be obtained.

Further, the organic EL element 8 is driven to display only when the external environment is dark, and when the light is bright, the MEMS element 9 is used to save power.
Since the organic EL element 8 can be reflected from the first cathode 41 to emit light from the common transparent substrate 2 side, it is reflected by the first cathode 41 in addition to the light obtained directly from the common transparent substrate 2 side and returns. Since the emitted light also contributes to light emission, display with sufficient visibility can be performed even in a bright environment.

  Furthermore, by using a material with improved light transmittance of the first cathode 41, light emitted from the organic EL element 7 is extracted from the first cathode 41 side, and light emitted from the MEMS element 9 is emitted from the common transparent substrate 2 side. Therefore, image information can be displayed on the first cathode 41 side, and the degree of freedom of the user can be increased on the common transparent substrate 2 side.

It is a top view which shows the organic electroluminescent display which concerns on embodiment of this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Organic EL display, 2 ... Common transparent substrate, 3 ... Anode, 4 ... Cathode, 41 ... 1st cathode, 42 ... 2nd cathode, 5 ... Spacer, 6 ... Space | gap, 7 ... Organic EL layer, 71 ... Hole Transport layer 72 ... Light emitting layer 73 ... Electron transport layer 8 ... Organic EL device 9 ... MEMS device

Claims (1)

In an organic EL display that displays image information and character information,
A plurality of anodes arranged in a horizontal direction on a common transparent substrate;
A plurality of cathodes having a set of a first cathode and a second cathode having a predetermined interval from the plurality of anodes and arranged in a direction orthogonal to the plurality of anodes;
An organic EL layer formed at and between the plurality of anodes and the first cathode; and
A spacer provided at an intersection of the plurality of anodes and the second cathode and provided therebetween,
The organic EL display, wherein the second cathode is made of an elastic body that moves up and down in a direction perpendicular to the plurality of anodes.

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