JP2002299039A - Organic electroluminescence display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescence display cap of fully protecting privacy by limiting the angle of visibility. SOLUTION: An anode electrode 12 and a luminescent element layer 14 are formed by each pixel on a circuit board 10, and a cathode electrode 16 is formed on them to constitute an organic electroluminescence element, which is used as a light source in the organic electroluminescence display, and in the organic electroluminescence displays, an optical means 18 for imparting directivity to the emitted light is mounted on the light-emitting face of the circuit board 10. Because of the optical means 18, the diffused light emitted from the luminescence element layer 14 is collected and directivity is imparted to the collected light. Therefore, the angle of visibility of the organic electroluminescence display can be limited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent display, and more particularly to an improvement in the directivity of an organic electroluminescent display.

[0002]

2. Description of the Related Art As shown in FIG. 5, an organic electroluminescent display comprises an anode electrode 12,
An organic electroluminescent element including a light emitting element layer 14 and a cathode electrode 16 formed of an organic substance having a property of emitting light by recombination of electrons and holes is formed. The organic electroluminescent device includes at least one of the anode electrode 12 and the cathode electrode 16 and the light emitting device layer 1.
4 is formed for each pixel and functions as a light source.

[0003] Such an organic electroluminescent display consumes less power than a CRT and can be made thinner as a flat display. further,
Since the organic electroluminescent display is of a self-luminous type, clear display can be realized as compared with other flat displays such as a liquid crystal display. Therefore, a high-performance display device can be realized by the organic electroluminescent display.

[0004]

However, unlike the LCD, the conventional organic electroluminescent display is a set of self-luminous point light sources, so that the viewing angle is not limited. That is, the viewing angles in the vertical and horizontal directions are extremely wide. For this reason, for example, when used in a display for a mobile phone or the like, since the display content can be viewed by another person next to or in front of the viewer of the display,
There has been a problem that privacy protection tends to be insufficient.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an organic electroluminescent display capable of improving directivity and sufficiently protecting privacy.

[0006]

In order to achieve the above object, the present invention relates to an organic electroluminescent display in which an organic electroluminescent element is formed for each pixel. And an optical unit for giving directivity to the emitted light.

According to the above configuration, the optical means for providing a directivity to the emitted light is provided on the light emitting surface side with a pitch for each pixel, so that the directivity of the emitted light is enhanced, and the organic electroluminescence is provided. The viewing angle of a portable display can be limited.

In the organic electroluminescent display, the optical means is any one of a Fresnel lens, a lenticular lens, a microlens, and a lens constituted by a combination of members having different refractive indexes.

According to the above configuration, the viewing angle of the organic electroluminescent display can be narrowed with a simple configuration by using various lenses.

[0010]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an example of the structure of an organic electroluminescent display according to the present invention. In FIG. 1, an anode 12, a light emitting element layer 14 including at least a light emitting layer, and a cathode electrode 16 are formed on a substrate 10 to constitute an organic electroluminescent element. In this organic electroluminescent device, an anode electrode 12 and a light emitting device layer 14 are formed for each pixel.

A feature of the present embodiment is that the light emitted from the light emitting element layer 14 has directivity on the light emitting surface side of the substrate 10 of the organic electroluminescent display using the organic electroluminescent element as a light source. That is, the optical means 18 for providing the The light from the light emitting element layer 14 that normally diverges is collected by the optical unit 18,
As shown in FIG. 1, the light travels in a substantially constant direction.
For this reason, the viewing angle of the organic electroluminescent display can be limited to prevent a person other than the observer from seeing the screen display. For this reason, privacy can be sufficiently protected. Further, the directivity is enhanced in a specific direction by the optical means 18, so that a brighter display can be seen for the observer.

The anode electrode 12 shown in FIG.
The light emitting element layer 14 is provided independently for each pixel, but one optical means 18 may be provided on the entire light emission surface of the organic electroluminescent display. However, it is preferable that the optical unit 18 has a pitch for each pixel and provides directivity to the emitted light for each pixel. Thereby, higher directivity can be given to the emitted light.

Further, as described above, by providing the optical means 18 on the emission surface side of the substrate 10, light can be collected in a certain direction, so that the organic electroluminescent display can have high brightness.

As the optical means 18 described above, a lens can be used. Examples of such a lens are shown in FIGS.

FIG. 2 shows an example of a sectional view of a Fresnel lens. FIGS. 3A and 3B show examples of sectional views of the lenticular lens. Each of the lenses shown in FIGS. 2 and 3 is a concave lens and has a function of collecting divergent light.

In addition to these Fresnel lenses and lenticular lenses, it is also possible to use microlenses in which small concave lenses are arranged in a plane. In this case,
The arrangement of the microlenses is set to a pitch suitable for the arrangement of each pixel.

FIG. 4 shows a type of lens in which three members having different refractive indexes are laminated. The three members 20, 21, and 22 shown in FIG. 4 are formed of materials having different refractive indexes, and the function of the concave lens can be provided by the combination of the refractive indexes and the shape of the interface between the members.

As described above, by using various concave lenses as the optical means 18, it is possible to impart directivity to the emitted light with a simple configuration, and to easily narrow the viewing angle of the organic electroluminescent display. Can be.

In order for the Fresnel lens and the lenticular lens to have a pitch for each pixel, the pitch must be for each pixel in either the row direction or the column direction. This is because the Fresnel lens is a concentric lens, the pitch of which is a pitch in the row direction or the column direction, and the lenticular lens is a semi-cylindrical lens extending at a predetermined pitch in the row direction or the column direction. It is.

[0021]

As described above, according to the present invention,
The viewing angle of the organic electroluminescent display can be limited, and high luminance can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a configuration example of an organic electroluminescent display according to the present invention.

FIG. 2 is a sectional view of a Fresnel lens used as an optical unit.

FIG. 3 is a sectional view of a lenticular lens used as an optical unit.

FIG. 4 is a cross-sectional view of a lens configured as a combination of members having different refractive indexes used as an optical unit.

FIG. 5 is a cross-sectional view of a conventional organic electroluminescent display.

[Explanation of symbols]

10 substrate, 12 anode electrode, 14 light emitting element layer,
16 cathode electrode, 18 optical means, 20, 21, 22
2 members.

Claims (2)

[Claims] An organic electroluminescent display in which an organic electroluminescent element is formed for each pixel, the organic electroluminescent display having a pitch for each pixel on a light emitting surface side, and imparting directivity to emitted light. An organic electroluminescent display comprising optical means. 2. The organic electroluminescent display according to claim 1, wherein said optical means is any one of a Fresnel lens, a lenticular lens, a microlens, and a lens constituted by a combination of members having different refractive indexes. Organic electroluminescent display.