JP2015225778A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress generation of brightness nonuniformity of light emitted from each light-emitting area.SOLUTION: A light-emitting device 100 includes: an organic EL panel 10 having a light-emitting area 11; and an organic EL panel 20, having a light-emitting area 21, electrically connected in series to the organic EL panel 10. The light-emitting area 11 and the light-emitting area 21 have mutually different shapes. An area S1 of the light-emitting area 11 and an area S2 of the light-emitting area 21 are roughly the same.

Description

  The present invention relates to a light emitting device including a plurality of organic EL panels.

  On the main surface (light emitting surface) of the organic EL panel, a light emitting region that emits light and a non-light emitting region that emits little or no light are formed. In general, the non-light emitting region is formed by sealing the light emitting layer or providing wiring for supplying power to the light emitting layer.

  Japanese Patent Application Laid-Open No. 04-255692 (Patent Document 1) discloses an invention in which a non-light emitting region is formed by irradiating a light emitting layer of an organic EL panel with ultraviolet rays. The publication states that, by irradiation with ultraviolet rays, the shape of the non-light-emitting region can be easily patterned, and thus a light-emitting region having a desired shape can be realized.

Japanese Patent Laid-Open No. 04-255692

  In a conventional light emitting device, when a plurality of organic EL panels electrically connected in series are driven with a constant current, the luminance of light emitted from the light emitting region of one organic EL panel and the other organic EL panels There may be unevenness (brightness difference) between the brightness of light emitted from the light emitting region. This was the same when driving at a constant voltage.

  The present invention is a light emitting device capable of suppressing unevenness in luminance of light emitted from each light emitting region when driving a plurality of organic EL panels electrically connected in series with a constant current or a constant voltage. The purpose is to provide.

  A light emitting device according to the present invention includes a first organic EL panel having a first light emitting region, a second organic EL panel having a second light emitting region and electrically connected in series to the first organic EL panel, The first light emitting region and the second light emitting region have different shapes, and the area of the first light emitting region and the area of the second light emitting region are substantially the same.

  Preferably, the non-light emitting region of the first organic EL panel and / or the non-light emitting region of the second organic EL panel is formed by irradiating the light emitting layer with light.

  Preferably, the apparatus further includes a mask plate, wherein the first light emitting region includes a light emitting region covered with the mask plate and another light emitting region not covered with the mask plate, the area of the light emitting region and the other The total area of the light emitting regions is substantially the same as the area of the second light emitting region.

  According to the light emitting device having the above configuration, when driving a plurality of organic EL panels electrically connected in series, it is possible to suppress unevenness in luminance of light emitted from each light emitting region.

FIG. 3 is a front view illustrating the light-emitting device according to Embodiment 1. FIG. 3 is a front view illustrating a state when the light-emitting device in Embodiment 1 emits light. 4 is a rear view showing an organic EL panel provided in the light emitting device in Embodiment 1. FIG. It is arrow sectional drawing along the IV-IV line in FIG. FIG. 6 is a front view showing a light emitting device in a second embodiment. FIG. 6 is a front view showing an exploded state of the light emitting device in the second embodiment.

[Embodiment 1]
With reference to FIGS. 1-4, the light-emitting device 100 in Embodiment 1 is demonstrated. FIG. 1 is a front view showing the light emitting device 100. FIG. 2 is a front view showing a state when the light emitting device 100 emits light. As illustrated in FIG. 1, the light emitting device 100 includes an organic EL panel 10 as a first organic EL panel, an organic EL panel 20 as a second organic EL panel, and wiring members 31 to 33.

  The organic EL panel 10 includes a light emitting region 11 (first light emitting region) that emits light and a non-light emitting region 12 that emits little or no light. The organic EL panel 20 includes a light emitting region 21 that emits light (second light emitting region) and a non-light emitting region 22 that emits little or no light. The wiring members 31 to 33 electrically connect the organic EL panel 10 and the organic EL panel 20 in series.

  Referring to FIG. 2, a drive circuit (not shown) drives organic EL panels 10 and 20 with a constant current via wiring members 31 to 33. The organic EL panels 10 and 20 may be driven with a constant voltage. The diagonally hatched hatching in FIG. 2 is attached to the portions corresponding to the non-light emitting areas 12 and 22, and the non-light emitting areas 12 and 22 are darker than the light emitting areas 11 and 21, and emit light. It is schematically shown that a state that is not present is formed.

(Organic EL panel 10, 20)
FIG. 3 is a rear view showing the organic EL panel 10, and shows a state when the organic EL panel 10 is viewed from the side opposite to the light emitting surface 10 </ b> S (FIG. 4) side of the organic EL panel 10. The light emitting surface 10 </ b> S is a surface on the outer surface of the organic EL panel 10 where the light emitting region 11 and the non-light emitting region 12 are formed. 4 is a cross-sectional view taken along line IV-IV in FIG.

  A detailed configuration of the organic EL panels 10 and 20 will be described below with reference to FIGS. 3 and 4. The organic EL panels 10 and 20 have substantially the same configuration except that the shapes of the light emitting regions 11 and 21 (see FIGS. 1 and 2) are different from each other. The description of the organic EL panel 20 will not be repeated.

  Referring mainly to FIG. 4, the organic EL panel 10 includes a transparent substrate 13, an anode 14, a light emitting layer 15, a cathode 16, a sealing member 17, and an insulating layer 18. The transparent substrate 13 is composed of various glass substrates, for example. The transparent substrate 13 is a member that forms the light emitting surface 10 </ b> S of the organic EL panel 10. As described above, the light emitting surface 11 of the organic EL panel 10 is formed with the light emitting region 11 that emits light and the non-light emitting region 12 that emits little or no light.

  The anode 14 is a conductive film having transparency. The anode 14 is formed by depositing ITO (Indium Tin Oxide) or the like on the transparent substrate 13 by sputtering or the like. The ITO film forming the anode 14 is divided into two regions by patterning in order to form an electrode extraction portion 10E (for anode) and an electrode extraction portion 10F (for cathode). The ITO film of the electrode extraction portion 10F is connected to the cathode 16.

  The light emitting layer 15 generates light when supplied with electric power. The light emitting layer 15 may be composed of a single light emitting layer, or may be composed of a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, and the like that are sequentially laminated. The cathode 16 is, for example, aluminum (AL). The cathode 16 is formed so as to cover the light emitting layer 15 by a vacuum deposition method or the like.

An insulating layer 18 is provided between the cathode 16 and the anode 14 so that the cathode 16 and the anode 14 are not short-circuited. A portion of the cathode 16 opposite to the side on which the insulating layer 18 is provided is connected to the electrode extraction portion 10F. The insulating layer 18 is formed in a desired pattern so as to cover a portion that insulates the anode 14 and the cathode 16 from each other using a photolithography method or the like after, for example, a SiO ₂ film is formed using a sputtering method. .

  The sealing member 17 is made of an insulating resin or glass substrate. The sealing member 17 is formed to protect the light emitting layer 15 from moisture and the like. The sealing member 17 seals the whole of the anode 14, the light emitting layer 15, and the cathode 16 on the transparent substrate 13. The electrode extraction part 10E and the electrode extraction part 10F are exposed from the sealing member 17 for electrical connection. Wiring members 31 to 33 (see FIGS. 1 and 2) are attached to the electrode extraction portion 10E and the electrode extraction portion 10F using soldering (silver paste) or the like.

  1 and 2 again, the light emitting region 11 of the organic EL panel 10 has an arrow shape pointing to the right side of the drawing. The light emitting region 21 of the organic EL panel 20 has a flag shape that flutters in the wind. That is, the light emitting region 11 and the light emitting region 21 have different shapes. As long as the shape of the light emitting region 11 and the shape of the light emitting region 21 are different from each other, any shape different from that shown in FIGS. 1 and 2 can be adopted. The shape of the light emitting areas 11 and 21 here refers to a design (pattern or pattern in the figure), characters, images, or the like formed by the light emitting areas 11 and 21.

  On the other hand, in the present embodiment, the area S1 of the light emitting region 11 and the area S2 of the light emitting region 21 are configured to have substantially the same value. The fact that the area S1 and the area S2 are substantially the same is not limited to the case where the areas S1 and S2 are completely the same value, and the ratio of the area S2 to the area S1 is within a range of 0.90 to 1.10. Is also included. Preferably, the ratio of the area S2 to the area S1 is in the range of 0.95 to 1.05.

  The light emitting regions 11 and 21 having the shapes as described above can be easily obtained by irradiating the organic light emitting layer (light emitting layer 15) with light in the manufacturing process of the organic EL panels 10 and 20. That is, by irradiating light, the functions of the hole transport layer and the like constituting the organic light emitting layer (light emitting layer 15) are changed. The light to be irradiated may contain ultraviolet rays, visible rays or infrared rays, but preferably contains ultraviolet rays. Ultraviolet light means an electromagnetic wave having a wavelength longer than that of X-rays and shorter than the shortest wavelength of visible light, and specifically has a wavelength in the range of 1 to 400 nm.

  A mask is previously provided in a portion where the light emitting regions 11 and 21 are formed. When light is not irradiated, that is, a portion of the organic light-emitting layer that was originally supposed to form a light-emitting region forms a non-light-emitting region by receiving light irradiation. Of the organic light emitting layer that was originally planned to form the light emitting region, the portions other than the portion that formed the non-light emitting region are provided with the light emitting regions 11 and 21 corresponding to the shape of the mask pattern. Will be configured. Such a light irradiation process is preferably performed after the sealing member 17 (see FIG. 4) is formed in the manufacturing process of the organic EL panel.

  The light emitting regions 11 and 21 can be obtained by a method other than the above-described light irradiation method. For example, the light emitting regions 11 and 21 can be obtained by providing the anode 14 and / or the cathode 16 so as to have a shape corresponding to the shape of the light emitting regions 11 and 21 in the manufacturing process of the organic EL panels 10 and 20. it can. The anode 14 and the cathode 16 can be configured to have desired shapes by a sputtering method using a mask pattern, a photolithography method, or the like.

(Function and effect)
In a plurality of organic EL panels electrically connected in series, if the areas of the respective light emitting regions are different, the brightness of the light emitted from each of the light emitting regions is uneven when driven by constant current. This is because, when driven at a constant current, the same current flows per panel, so the current density per unit area of the light emitting region is different, and the brightness of the light emitted from the light emitting region is uneven. That's it. The same applies to the case of driving at a constant voltage.

  In the present embodiment, the area S1 of the light emitting region 11 and the area S2 of the light emitting region 21 are configured to have substantially the same value. Therefore, the current density per unit area of the light emitting region 11 and the current density per unit area of the light emitting region 21 take substantially the same value, and luminance unevenness occurs between the light emitting region 11 and the light emitting region 21. It rarely happens. That is, according to the idea disclosed in the first embodiment, when driving a plurality of organic EL panels electrically connected in series, unevenness occurs in the luminance of light emitted from each light emitting region. It can be said that it can be suppressed.

[Embodiment 2]
With reference to FIG. 5 and FIG. 6, the light-emitting device 200 in Embodiment 2 is demonstrated. Here, differences between the light emitting device 200 and the light emitting device 100 according to the first embodiment will be mainly described. FIG. 5 is a front view showing the light emitting device 200. FIG. 6 is a front view showing the disassembled state of the light emitting device 200.

  The light emitting device 200 further includes a mask plate 40. The mask plate 40 has rectangular openings 41 and 42 that roughly correspond to the arrangement and shape of the organic EL panels 10 and 20, and a part of the mask plate 40 overlaps the organic EL panels 10 and 20 from the front side. (See arrow AR in FIG. 6).

  The light emitting region 11 of the organic EL panel 10 of the present embodiment includes light emitting regions 11A, 11B, and 11C. The light emitting regions 11 </ b> A and 11 </ b> C are covered with the mask plate 40 when the mask plate 40 is disposed so that a part of the mask plate 40 overlaps the organic EL panels 10 and 20. The light emitting region 11B (other light emitting regions) is not covered with the mask plate 40 when the mask plate 40 is disposed so that a part of the mask plate 40 overlaps the organic EL panels 10 and 20.

  Here, the total value of the areas of the light emitting regions 11A and 11C and the area of the light emitting region 11B is substantially the same as that of the light emitting region 21. The fact that the total value and the area S2 are substantially the same is not limited to the case where the total value and the area S2 are completely the same value, and the ratio of the area S2 to the total value is 0.90 or more and 1.10. Cases within the following range are also included. Preferably, the ratio of the area S2 to the total value is in the range of 0.95 to 1.05. The light emitting regions 11A, 11B, and 11C having such a shape can also be obtained by a method similar to the method described in the first embodiment.

(Function and effect)
In the present embodiment, the light emitting region 11B of the organic EL panel 10 and the light emitting region 21 of the organic EL panel 20 have different areas, but can emit light with substantially the same luminance. That is, even when it is desired to make the areas of the light emitting region 11B (the region that is ultimately desired to be illuminated as a finished product) and the light emitting region 21 different from each other, the light emitting regions 11A and 11C are provided as so-called discard patterns (or dummy patterns). Thus, the total area of the light emitting regions 11A, 11B, and 11C and the area of the light emitting region 21 can be made substantially the same.

  Therefore, the current density per unit area of the light emitting region 11B and the current density per unit area of the light emitting region 21 take substantially the same value, and there is luminance unevenness between the light emitting region 11B and the light emitting region 21. It rarely happens. In other words, even when the plurality of organic EL panels electrically connected in series are driven, unevenness in the luminance of light emitted from each light emitting region is suppressed by the idea disclosed in the second embodiment. I can say that.

  Although the embodiment has been described above, the above disclosure is illustrative in all respects and is not restrictive. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 10 Organic EL panel (1st organic EL panel), 10E, 10F Electrode extraction part, 10S Light emission surface, 11 Light emission area (1st light emission area), 11A, 11C Light emission area, 11B Light emission area (other light emission area), 12 , 22 Non-light emitting area, 13 Transparent substrate, 14 Anode, 15 Light emitting layer, 16 Cathode, 17 Sealing member, 18 Insulating layer, 20 Organic EL panel (second organic EL panel), 21 Light emitting area (second light emitting area) , 31, 32, 33 Wiring member, 40 mask plate, 41, 42 opening, 100, 200 light emitting device, AR arrow, S1, S2 area.

Claims (3)

A first organic EL panel having a first light emitting region;
A second organic EL panel having a second light emitting region and electrically connected in series to the first organic EL panel,
The first light emitting region and the second light emitting region are different from each other,
The area of the first light emitting region and the area of the second light emitting region are substantially the same.
Light emitting device. The non-light-emitting region of the first organic EL panel and / or the non-light-emitting region of the second organic EL panel is formed by irradiating the light emitting layer with light.
The light emitting device according to claim 1. A mask plate,
The first light emitting area includes a light emitting area covered by the mask plate and another light emitting area not covered by the mask plate,
The total value of the area of the light emitting region and the area of the other light emitting region is substantially the same as the area of the second light emitting region.
The light emitting device according to claim 1.

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