Organic el light-emitting device

Abstract

The present invention provides an organic EL light-emitting device in which a non-light-emitting region is less likely to be visually recognized during lighting, as compared to conventional products.　The present invention has an organic EL light-emitting element and a light output substrate. The light output substrate is provided on a light output side of the organic EL light-emitting element. On the surface on the light output side of the light output substrate, a light output region is present at a portion facing a light-emitting region of the organic EL light-emitting element, and when the light output substrate is viewed in a plan view, the light output substrate has a non-light-emitting region and a light extraction part is provided at a position overlapping the non-light-emitting region. The light extraction part is configured to have a recessed structure which is recessed relative to the light output region or a protruding structure which protrudes relative to the light output region.

Description

Organic EL light-emitting device

[0001] The present invention relates to an organic EL light-emitting device, and specifically relates to an organic EL light-emitting element utilizing the organic electroluminescence (EL) phenomenon, and a display device and a lighting device including the same.

[0002] An organic EL element is a solid-state light-emitting element that converts electric energy into light energy. Various display devices and lighting devices using the same are mainly characterized by being lightweight and thin, and research and commercialization thereof are progressing in various fields.

[0003] Among these, in particular, lighting devices using organic EL elements can irradiate soft diffused light as a surface light source and do not contain a large amount of harmful short-wavelength light, compared with lighting devices using light-emitting diodes (LEDs) that have rapidly spread in recent years (hereinafter also referred to as LED lighting). Therefore, they are attracting attention as next-generation lighting sources in a wide range of fields ranging from general housing to special applications such as inspection light sources.

[0004] Here, organic EL elements for lighting devices are often formed on a glass substrate, and generally emit uniform white light or monochromatic light from a light-emitting surface having a predetermined area such as a square or a rectangle. On the other hand, in LED lighting, LED elements with different emission colors, more specifically, three types of LEDs: red LED, green LED, and blue LED, or two types of LEDs: blue LED and orange LED which is a complementary color to blue LED, are combined to adjust the amount and tone of light. So-called dimmable and color-tunable lighting is already available on the market.

[0005] In contrast, several organic EL lighting devices capable of dimming and color tuning have been reported even for lighting devices using organic EL elements, in which two or more types of light-emitting regions having different emission colors are separately arranged in a pixel shape or stripe shape on the substrate surface, and the driving currents for causing the light-emitting regions of each color to emit light are individually adjusted.

[0006] JP 2016-006744 A, JP 2017-076467 A, Japanese Patent No. 5241783

[0007] Incidentally, when dimming and color tuning are performed by forming light-emitting regions of different colors in a striped pattern on the substrate surface as described above, non-light-emitting regions are generally formed between the light-emitting regions of each color (between the stripes). This is because, when forming each striped light-emitting region on the substrate, patterning of the transparent electrodes (separating the light-emitting regions for each color) and patterning of the organic material thin film formed on the transparent electrodes by vacuum deposition or the like are performed. This is a major factor in reducing the aperture ratio (the ratio of the area of ​​the actually light-emitting part to the total area of ​​the organic EL element), and the non-light-emitting regions become visible as dark areas within the light-emitting regions. The effect of these non-light-emitting regions becomes more pronounced as the area of ​​each color's light-emitting region becomes smaller and therefore cannot be ignored. A decrease in aperture ratio leads to a decrease in the amount of emitted light, and the visibility of non-light-emitting regions leads to a decrease in design aesthetics, so neither is desirable.

[0008] To minimize the impact of this non-emitting region, one approach is to enlarge the emission region of each color to effectively reduce the contribution of the non-emitting region. However, in this case, the emission regions of each color become clearly visible separately. For example, when attempting to represent white using blue light emission and its complementary color, orange light emission, the blue and orange emission regions would be visible separately despite the use of white lighting, thus reducing the aesthetic appeal from another perspective. Another approach is to attach a light-diffusing sheet to the light-emitting side of the organic EL panel (the substrate surface opposite to the substrate surface where the electrodes and thin films of organic material are formed, the surface in contact with the outside) to make the non-emitting region less visible. However, it is difficult to completely eliminate the visibility of this non-emitting region, and there are concerns about increased labor and costs due to the attachment of the light-diffusing sheet.

[0009] Therefore, the present invention aims to provide an organic EL light-emitting device in which the non-light-emitting area is less visible when lit compared to conventional devices.

[0010] To solve the aforementioned problem, the inventors investigated a simple method for making the non-emitting region difficult to see. Specifically, the inventors formed a concave or convex structure along the non-emitting region on the light-emitting side surface of the organic EL panel constituting the organic EL lighting device, thereby extracting some or all of the radiated light from the light-emitting region when power is applied and the light propagating within the substrate in the direction of the substrate surface (hereinafter also referred to as substrate mode light) from the non-emitting region to the light-emitting side of the organic EL panel through reflection, refraction, and scattering. By doing so, the inventors believed that the non-emitting region could be made difficult to see, improving the design and further improving the aperture ratio.

[0011] Specifically, in organic EL lighting devices, organic EL panels are formed on a substrate of a certain thickness. However, in this case, much of the light emitted from the light-emitting region toward the substrate is reflected due to the refractive index difference between the substrate material (such as glass) and the outside air, causing it to propagate laterally within the substrate. As a result, most of this light cannot exit the substrate from the light-emitting side. Therefore, the inventors considered that by forming the aforementioned concave or convex structure on the light-emitting side of the substrate, some or all of this light can be converted into light that exits the light-emitting side of the substrate. By utilizing this phenomenon and providing the aforementioned concave or convex structure in the non-light-emitting region on the light-emitting side of the substrate, it is possible to make this non-light-emitting region less visible, thereby improving the design and further improving the aperture ratio.

[0012] One aspect of the present invention derived from the above considerations is an organic EL light-emitting device comprising an organic EL light-emitting element and a light-emitting substrate, wherein the light-emitting substrate is provided on the light-emitting side of the organic EL light-emitting element, the surface of the light-emitting substrate on the light-emitting side has a light-emitting region in a portion facing the light-emitting region of the organic EL light-emitting element, the light-emitting substrate has a non-light-emitting region when viewed from above, and a light extraction portion is provided at a position overlapping with the non-light-emitting region, the light extraction portion includes a concave structure recessed with respect to the light-emitting region and / or a convex structure protruding with respect to the light-emitting region.

[0013] According to this embodiment, the light extraction unit, which is positioned to overlap with the non-emitting region, can extract the light emitted from the light-emitting region when power is applied, as well as the light propagating within the light-emitting substrate in the direction inward of the light-emitting substrate surface. When the light is turned on, the light extraction unit glows, making the non-emitting region less visible compared to conventional designs.

[0014] In a preferred embodiment, the non-emitting region extends in a predetermined direction, and the light extraction portion extends along the direction of extension of the non-emitting region.

[0015] A preferred embodiment includes a concave structure recessed relative to the light emission region, wherein the concave structure is linear or dotted.

[0016] In a preferred embodiment, the light extraction portion includes a recessed structure that is recessed relative to the light emission region, and the recessed structure has scribe marks.

[0017] In this context, "scribe marks" refer to processing marks that occur during scribing using a diamond scriber, laser, or other similar tools, and are formed by minute grooves, cracks, and other features.

[0018] In a preferred embodiment, the light extraction section includes a recessed structure that is recessed relative to the light emission area, and the recessed structure has blast marks.

[0019] In this context, "blast marks" refer to processing marks that occur during blasting, a process in which abrasive materials such as sand, steel slabs, or ceramics are blasted onto a surface. These marks are formed by minute irregularities.

[0020] A preferred embodiment includes a recessed structure in the light extraction area that is recessed relative to the light emission area, and the recessed structure has etching marks.

[0021] In this context, "etching marks" refer to processing marks that occur during etching, a process that involves corrosion using etchants or gases.

[0022] A preferred embodiment is that the light extraction portion includes a recessed structure recessed with respect to the light emission region, wherein the depth of the recessed structure is less than half the thickness of the light emission substrate.

[0023] In a preferred embodiment, the light extraction section includes a convex structure that protrudes from the light emission region, and the convex structure is made of a photocurable resin or a thermosetting resin.

[0024] In a preferred embodiment, the light extraction portion includes a convex structure that protrudes from the light emission region, and the convex structure is made of a resin tape or a resin seal.

[0025] In a preferred embodiment, the light emission region is smoother than the light extraction portion.

[0026] A preferred embodiment includes a second organic EL light-emitting element, wherein the light-emitting side surface of the light-emitting substrate has a second light-emitting region in the portion facing the light-emitting region of the second organic EL light-emitting element, and the non-light-emitting region is formed between the light-emitting region and the second light-emitting region when the light-emitting substrate is viewed from above.

[0027] A preferred embodiment is that the first organic EL light-emitting element and the second organic EL light-emitting element have different light-emitting colors in their light-emitting regions when lit.

[0028] In a preferred embodiment, the refractive index of the light-emitting substrate is smaller than the refractive index near the interface between the organic EL light-emitting element and the light-emitting substrate.

[0029] A preferred embodiment is that the refractive index of the light-emitting substrate is smaller than the refractive index of the portion of the organic EL light-emitting element that is closer to the light-emitting region than the light-emitting region.

[0030] In a preferred embodiment, the refractive index of the light-emitting substrate is greater than 1.

[0031] One aspect of the present invention is an organic EL light-emitting device having a stripe-shaped or similar non-emitting region within its light-emitting surface, wherein linear or dot-shaped concave structures are formed on the non-emitting region on the light-emitting side surface of the substrate for the purpose of light extraction.

[0032] One aspect of the present invention is an organic EL light-emitting device having a stripe-shaped or similar non-emitting region within its light-emitting surface, wherein linear or dot-shaped convex structures are formed on the non-emitting region on the light-emitting side surface of the substrate for the purpose of light extraction.

[0033] In one embodiment of the present invention, the concave structure may be formed on the light-emitting side of the substrate (light-emitting substrate) of the organic EL panel by a scribe method along a non-light-emitting region.

[0034] In another embodiment of the present invention, the concave structure may be formed on the light-emitting side of the substrate (light-emitting substrate) of the organic EL panel along the non-light-emitting region by sandblasting, laser scribing, or etching.

[0035] In another embodiment of the present invention, the convex structure may be formed by applying a thermosetting resin or a photocurable resin along a non-emitting region on the light-emitting side of the substrate (light-emitting substrate) of the organic EL panel and curing it.

[0036] In another embodiment of the present invention, the convex structure may be formed by attaching a resin tape or resin seal along the non-emitting region on the light-emitting side of the substrate (light-emitting substrate) of the organic EL panel.

[0037] Here, the concave structure and the convex structure are not limited to those formed by the method described above. The method described above is merely an example, and various forming methods capable of obtaining the light extraction effect are included.

[0038] As described above, the depth of the concave structure is preferably less than half the thickness of the substrate (light-emitting substrate) from the viewpoint of maintaining the mechanical strength of the substrate.

[0039] The above-described embodiments can be dependent on each other, refer to some of their components, or substitute for some of their components, as long as they fall within the technical scope of the present invention.

[0040] According to the present invention, when the light is on, the non-emitting area is less visible compared to conventional methods.

[0041] This figure shows an example of the cross-sectional structure of an organic EL panel. This figure shows organic EL elements formed in a stripe pattern on a substrate. This figure shows an example of light being emitted from an organic EL element. This figure shows an example of a concave structure provided on the light-emitting side of the substrate. This is an explanatory diagram of the organic EL panel of Figure 4, where (a) is a cross-sectional perspective view of the main part seen from the back side, and (b) is a cross-sectional perspective view of the main part seen from the light-emitting side. In both (a) and (b), the sealing layer is omitted for ease of understanding. This figure shows an example of a convex structure provided on the light-emitting side of the substrate. This is an explanatory diagram of the organic EL panel of Figure 6, where (a) is a cross-sectional perspective view of the main part seen from the back side, and (b) is a cross-sectional perspective view of the main part seen from the light-emitting side. This figure shows an example of an organic EL panel in which light is emitted from an organic EL element when a concave structure is provided on the substrate. Figure 4 is an explanatory diagram of another example of an organic EL panel, where (a) is a cross-sectional view when a linear concave structure is provided, and (b) is a perspective view when a dot-shaped concave structure is provided, with the sealing layer omitted in (b) for ease of understanding. This figure shows an example of light emission from an organic EL element when a convex structure is provided on the substrate. This is an experimental photograph when a scribe line (concave structure) is provided on the light emission side of a glass substrate.

[0042] The embodiments of the present invention will be described below with reference to the drawings. Please note that, for the sake of ease of understanding, the dimensions (length, width, and thickness) are exaggerated in the drawings, and therefore the ratios of each dimension do not accurately represent the dimensional ratios of the actual element.

[0043] (Embodiment) Figure 1 shows an example of a cross-sectional structure of an organic EL panel according to an embodiment. As shown in Figure 1, an organic EL panel is formed on a single substrate 100 (glass substrate, resin substrate, etc.) as a pair of lower electrodes 110 and upper electrodes 130, with an organic layer 120 sandwiched between them, formed as a thin film by vacuum deposition or printing. The entire element is covered with a sealing layer 140 made of a thin film of inorganic material such as silicon dioxide or silicon nitride to prevent the intrusion of moisture and oxygen from the outside, as well as mechanical damage. Here, depending on the improvement of element characteristics and the purpose of use of the organic EL element, the organic layer 120 is often made of a laminated structure of multiple organic layers, and for the lower electrode 110 and upper electrode 130, depending on whether the light emission surface is on the substrate 100 side (bottom emission structure) or on the sealing layer 140 side (top emission structure), a fully reflective film or semi-transparent film using metal, or a transparent conductive film using metal oxide is appropriately combined. In addition, the entire organic EL element 150 may be further protected by a sealing member made of glass or metal (sealing can, sealing glass, etc.). With regard to the present invention, there are no specific restrictions on these various element structures, and any element structure is included as long as the effects of the invention are achieved. Furthermore, unless otherwise specified, the present invention is described based on a bottom emission structure in which the synchrotron radiation generated in the organic layer 120 is emitted from the substrate 100 side to the outside of the organic EL panel, but any form of light emission direction is also included in the present invention as long as the effects of the invention are achieved.

[0044] In an organic EL panel for a lighting device, as shown in FIG. 2, an organic EL element 150 is formed in a thin film state over the entire surface of a substrate 100 by a vacuum evaporation method, a printing method, or the like, and the entire surface of the organic EL panel 200 emits light upon power input from the outside. In this case, as described above, the emission color is often limited to a specific color such as white light or monochromatic light, and a toning function that allows a user to freely control the emission color cannot be provided. For this reason, as in the organic EL panel 200, organic EL elements having different emission colors (organic EL elements 151 and 152 in FIG. 2) are formed in a stripe shape on the substrate 100, and these are driven separately, whereby the emission colors of the organic EL element 151 and the organic EL element 152 are appropriately mixed, thereby realizing a toning function that allows a user to obtain a desired emission color. More specifically, by setting the organic EL element 151 to blue and the organic EL element 152 to orange, and mixing these colors appropriately, various types of white including blue and orange can be realized. Further, although not described in detail here, in addition to the method of mixing two types of emission colors shown here, finer toning can also be performed by using a stripe structure having a plurality of different emission colors.

[0045] Here, 160 in the cross-sectional view of FIG. 2 schematically shows a partial cross-sectional view of the stripe structure of the tonable organic EL panel 201. The organic EL panel 201 has, on the substrate 100, stripes of an organic EL element 151 (a lower electrode 111, an organic layer 121, and an upper electrode 131) having a certain emission color, and an organic EL element 152 (a lower electrode 112, an organic layer 122, and an upper electrode 132) having an emission color different from that of the organic EL element 151, and the entire body is covered with a sealing layer 140. At this time, a gap 170 is formed between the stripe of the organic EL element 151 and the stripe of the organic EL element 152. This gap is inevitably generated because the stripe structure is formed by patterning through various methods, and when the tonable organic EL panel 201 emits light, the gap is visually recognized as a non-light-emitting region. That is, in the portion corresponding to the gap 170, the organic EL elements 151 and 152 are not formed, and this portion becomes a non-light-emitting region.

[0046] Here, the path of light emitted from the organic layer 121 will be described in detail with reference to FIG. 3. FIG. 3 is a schematic diagram of the tonable organic EL panel 201 of FIG. 2 during light emission. Here, for the sake of simplifying the description, a case where only the stripe of one color organic EL element 151 emits light is depicted, and among the light emitted from the organic layer 121, only a part of the path of light traveling toward the substrate 100 side is shown. Furthermore, since a bottom emission structure is taken as an example, the lower electrodes 111 and 112 are transparent electrodes. That is, FIG. 3 depicts a case where light is emitted from the light emitting region 123 of the organic layer 121 of one organic EL element 151 among the organic EL elements 151 and 152.

[0047] Light emitted from the light emitting region 123 in the organic layer 121 of the organic EL element 151 passes through the lower electrode 111 at various angles and reaches the inside of the substrate 100. Here, the lower electrode 111, the substrate 100, and the external air layer 180 generally each have different refractive indices for light (external air layer 180 < substrate 100 < lower electrode 111), so reflection occurs at the interface of each layer simultaneously with the transmission of light. In addition, when light travels from a layer with a large refractive index to a layer with a small refractive index, there is a critical angle (total reflection angle) of incident angle at which light cannot be transmitted to the outside. Light 300 represents light that can be transmitted to the external air layer 180 because the incident angle from the substrate 100 to the external air layer 180 is within the total reflection angle. On the other hand, light 301 represents light that cannot be transmitted from the substrate 100 to the external air layer 180 due to this total reflection and propagates inside the substrate 100 in the in-plane direction of the substrate 100 (hereinafter, also referred to as substrate mode light). Actually, similar light reflection occurs at the interfaces of other layers, but since the description is mainly focused on substrate mode light here, it is omitted.

[0048] The present invention is intended to extract this substrate mode light from the non-light-emitting region 170 to the external air layer 180 outside the substrate 100, and make it visually recognized that the non-light-emitting region 170 apparently emits light.

[0049] Figure 4 shows an example of a cross-sectional view in which a concave structure 400 is provided along the non-light-emitting region 170 on the light-emitting side of the substrate 100 constituting the organic EL panel 401. Here, although the concave structure 400 is depicted as an inverted V shape in Figure 4, the cross-sectional shape of the concave structure 400 is not particularly limited in this invention as long as the effects of the invention described above are obtained.

[0050] The organic EL panel 401 shown in Figure 4 will be described in detail below with reference to Figure 5.

[0051] Figure 5 is an explanatory diagram of the organic EL panel 401 according to the embodiment of Figure 4, and the sealing layer 140 has been omitted for ease of understanding.

[0052] As shown in Figure 5, the organic EL panel 401 has a first organic EL element 151 and a second organic EL element 152 stacked on a light-emitting substrate 100. The first organic EL element 151 and the second organic EL element 152 of the organic EL panel 401 are spaced apart in the width direction (the direction in which the organic EL elements 151 and 152 are arranged side by side), and a non-emitting region 170 that does not emit light when lit is formed between the first organic EL element 151 and the second organic EL element 152.

[0053] The light-emitting substrate 100 is a substrate that can transmit light in the thickness direction, and light-emitting regions 402 and 403 are formed on the light-emitting side, with a light extraction section 410 provided between the light-emitting regions 402 and 403. The light-emitting region 402 is a region that overlaps with the light-emitting region 123 of the first organic EL element 151 when viewed from above. The light-emitting region 403 is a region that overlaps with the light-emitting region 123 of the second organic EL element 152 when viewed from above. The light-emitting regions 402 and 403 are smoother and have less unevenness than the concave structure 400 of the light extraction section 410. That is, the surface roughness of the light-emitting regions 402 and 403 is less than that of the portion where the concave structure 400 is provided.

[0054] The light extraction section 410 is a part for extracting substrate mode light to the outside and is composed of one or more concave structures 400. The concave structure 400 is a groove formed in the light-emitting substrate 100, and is a bottomed groove that has depth from the light-emitting side surface of the light-emitting substrate 100 toward the organic EL elements 151 and 152 and extends in the longitudinal direction. As shown in Figure 5, the concave structure 400 extends inclined from the bottom and has inclined surfaces 405 and 406 having a thickness component and a width component.

[0055] Figure 6 also shows an example of a cross-sectional view in which a convex structure 500 is provided along the non-light-emitting region 170 on the light-emitting side of the substrate 100 constituting the organic EL panel 501. Here, the cross-sectional shape of the convex structure 500 is depicted as a semi-circular arc, but as with the case of Figure 4, the cross-sectional shape of the convex structure 500 is not particularly limited in this invention as long as the effects of the invention described above can be obtained.

[0056] The organic EL panel 501 shown in Figure 6 will be described in detail below with reference to Figure 7.

[0057] Figure 7 is an explanatory diagram of the organic EL panel 501 according to the embodiment of Figure 6, and the sealing layer 140 has been omitted for ease of understanding.

[0058] As shown in Figure 7, the organic EL panel 501 has a first organic EL element 151 and a second organic EL element 152 stacked on the back side of the light-emitting substrate 100, and a light extraction section 510 is stacked on the light-emitting side (front side).

[0059] The light-emitting substrate 100 is a substrate that can transmit light in the thickness direction, and light-emitting regions 502 and 503 are formed on the light-emitting side. The light-emitting region 502 is a region that overlaps with the light-emitting region 123 of the first organic EL element 151 when viewed from above. The light-emitting region 503 is a region that overlaps with the light-emitting region 123 of the second organic EL element 152 when viewed from above. The light-emitting regions 502 and 503 are smoother and have less unevenness than the convex structure 500 of the light extraction section 510. That is, the surface roughness of the light-emitting regions 502 and 503 is less than that of the portion where the convex structure 500 is provided.

[0060] The light extraction section 510 is a part for extracting substrate mode light to the outside and is composed of one or more convex structures 500. The convex structure 500 is a convex ridge that protrudes from the light-emitting side surface of the light-emitting substrate 100 toward the light-emitting side and extends in the longitudinal direction. The convex structure 500 has an arcuate surface 505 centered on the intermediate part between the light-emitting regions 502 and 503.

[0061] Figure 8 shows an example of light propagation from the light-emitting region 123 of the organic EL element 151 when a concave structure 400 is provided along the non-light-emitting region 170 on the light-emitting side of the substrate 100 in Figure 4. In this case, all or part of the light incident on the substrate 100 from the light-emitting region 123 at a certain angle, and the substrate mode light (light 301 in Figure 3) propagating within the substrate 100 in the direction inward of the substrate surface, is radiated from the concave structure 400 to the external air layer 180 (light 600) due to light transmission, reflection, and scattering phenomena at the concave structure 400 provided on the substrate 100. When a user views this from the light-emitting side of the substrate 100, it appears as if the non-light-emitting region 170 is emitting light. As a result, in a color-tunable organic EL lighting device consisting of multiple stripe structures with different emission colors, the user can perceive the entire surface as emitting light without being aware of the original non-light-emitting region 170.

[0062] One example of a method for forming the concave structure 400 shown in Figures 4, 5, and 8 is to scratch the light-emitting side of the substrate 100 along the non-emitting region 170 with a hard cutter such as a diamond blade. Specifically, if the substrate 100 is made of glass, a common material, the concave structure 400 can be easily formed on the light-emitting side of the substrate 100 by the scribe method used when separating organic EL panels individually from a large-area base substrate. In other words, the concave structure 400 in this case has scribe marks formed by the glass scribe method.

[0063] Another example of a method for forming the concave structure 400 shown in Figures 4, 5, and 8 is to form the concave structure 400 along the non-emitting region 170 on the light-emitting side surface of the substrate 100 by sandblasting. In this case, a mask is attached to protect the substrate 100 from the area where the concave structure 400 is to be formed, and the concave structure 400 can be formed only in the area corresponding to the non-emitting region 170 by sandblasting. In other words, the concave structure 400 in this case has blast marks formed by the sandblasting method.

[0064] Another example of a method for forming the concave structure 400 shown in Figures 4, 5, and 8 is to form the concave structure 400 on the light-emitting side of the substrate 100 along the non-emitting region 170 by etching. In this case, a mask is formed on the substrate 100 using a resist material or the like to protect the area other than where the concave structure 400 is to be formed, and the concave structure 400 can be formed only in the non-emitting region 170 by wet etching or dry etching. In other words, in this case, etching marks formed by the etching method are formed on the concave structure 400.

[0065] Here, although there are other methods for forming a concave structure 400 along the non-emitting region 170 on the light-emitting side surface of the substrate 100, the present invention does not specify a method for forming the concave structure 400, and any method that can form a concave structure 400 that provides the effects of the present invention is acceptable.

[0066] Furthermore, the depth of the concave structure 400 formed along the non-emitting region 170 on the light-emitting side of the substrate 100 is preferably 1 / 2 or less of the thickness of the substrate 100, taking into consideration the mechanical strength of the substrate 100.

[0067] Furthermore, the width of the concave structure 400 formed along the non-emitting region 170 on the light-emitting side surface of the substrate 100 is preferably within the width of the non-emitting region 170. However, if the width of the non-emitting region 170 is wide, multiple thin concave structures 400 may be provided linearly within the width of the non-emitting region 170, as shown in Figure 9(a). Alternatively, instead of linearly, multiple concave structures 400 may be provided in a dot-like (point-like) pattern, for example, as shown in Figure 9(b). In this case, adjacent concave structures 400 in the longitudinal direction may be connected or separated.

[0068] Next, an example of light propagation from the light-emitting region 123 of the organic EL element 151, when a convex structure 500 is provided along the non-light-emitting region 170 on the light-emitting side of the substrate 100, will be explained using Figure 10. In this case as well, similar to the concave structure 400 in Figure 8, all or part of the light incident on the substrate 100 from the light-emitting region 123 at a certain angle, and the substrate mode light (light 301 in Figure 3) propagating within the substrate 100 in the direction inward of the substrate surface, is radiated from the convex structure 500 to the external air layer 180 (light 700) due to the light transmission, reflection, and scattering phenomena of the convex structure 500 provided on the substrate 100. As a result, in a color-tunable organic EL lighting device consisting of multiple stripe structures with different emission colors, the user can see that the entire surface is emitting light without being aware of the original non-light-emitting region 170.

[0069] One example of a method for forming the convex structure 500 shown in Figures 6, 7, and 10 is to apply a resin such as an adhesive to the light-emitting side of the substrate 100 along the non-emitting region 170 and cure it. Specifically, by applying a thermosetting resin and / or a photocurable resin to the light-emitting side of the substrate 100 along the non-emitting region 170 and curing it, the convex structure 500 can be easily formed on the light-emitting side of the substrate 100.

[0070] Another example of a method for forming the convex structure 500 shown in Figures 6, 7, and 10 is to attach a resin tape or resin seal along the non-emitting region 170 to the light-emitting side surface of the substrate 100. This method allows for the easy formation of the convex structure 500 on the light-emitting side surface of the substrate 100.

[0071] Here, although other methods are conceivable for forming the convex structure 500 along the non-emitting region 170 on the light-emitting side surface of the substrate 100, the present invention does not specify the method for forming the convex structure 500, and any method that can form a convex structure 500 that provides the effects of the present invention is acceptable.

[0072] Furthermore, while it is desirable that the width of the convex structure 500 formed along the non-emitting region 170 on the light-emitting side surface of the substrate 100 be within the width of the non-emitting region 170, if the width of the non-emitting region 170 is wide, multiple thin convex structures 500 may be provided linearly within the width of the non-emitting region 170, similar to the concave structure 400 shown in Figure 9(a). Alternatively, instead of linearly, multiple convex structures 500 may be provided in a dot pattern, similar to the concave structure 400 shown in Figure 9(b).

[0073] Furthermore, after providing the concave structure 400 or convex structure 500 on the light-emitting side of the substrate 100, a light-diffusing film or the like may be attached to the light-emitting side of the substrate 100 for the purpose of improving the strength of the substrate 100 or for further light diffusion effects.

[0074] The organic EL light-emitting apparatus (organic EL panels 401, 501) according to the embodiment of the present invention comprises an organic EL element 151 (organic EL light-emitting element) and a light-emitting substrate 100, the light-emitting substrate 100 being provided on the light-emitting side of the organic EL element 151, the light-emitting side surface of the light-emitting substrate 100 having a light-emitting region 402 (502) in the portion facing the light-emitting region 123 of the organic EL element 151, the light-emitting substrate 100 having a non-light-emitting region 170 when viewed from above, and a light extraction portion 410 being provided at a position overlapping with the non-light-emitting region 170, the light extraction portion 410 including a concave structure 400 recessed relative to the light-emitting region 402 or a convex structure 500 protruding relative to the light-emitting region 502.

[0075] With this configuration, the light extraction units 410 and 510, which are positioned to overlap with the non-emitting region 170, can extract the substrate mode light when the device is lit to the outside. When the device is lit, the light extraction units 410 and 510 light up, making the non-emitting region 170 less visible compared to conventional designs.

[0076] In the organic EL light-emitting apparatus of the embodiment described above, the non-light-emitting region 170 extends in the longitudinal direction (a predetermined direction), and the light extraction sections 410 and 510 may extend along the direction of extension of the non-light-emitting region 170.

[0077] In the organic EL light-emitting device of the above embodiment, the light extraction section 410 includes a recessed structure 400 that is recessed relative to the light emission area 402, and the recessed structure 400 may be linear or dotted.

[0078] In the organic EL light-emitting apparatus of the above-described embodiment, the light extraction section 410 includes a recessed structure 400 that is recessed relative to the light emission area 402, and the recessed structure 400 may have scribe marks.

[0079] In the organic EL light-emitting apparatus of the above-described embodiment, the light extraction section 410 includes a recessed structure 400 that is recessed relative to the light emission area 402, and the recessed structure 400 may have blast marks.

[0080] In the organic EL light-emitting apparatus of the above embodiment, the light extraction section 410 includes a recessed structure 400 that is recessed relative to the light emission area 402, and the recessed structure 400 may have etching marks.

[0081] In the organic EL light-emitting apparatus of the above embodiment, the light extraction section 410 includes a recessed structure 400 that is recessed relative to the light emission area 402, and the depth of the recessed structure 400 may be less than half the thickness of the light emission substrate 100.

[0082] In the organic EL light-emitting device of the above embodiment, the light extraction section 510 includes a convex structure 500 that protrudes from the light emission area 502, and the convex structure 500 may be made of a photocurable resin or a thermosetting resin.

[0083] In the organic EL light-emitting device of the above embodiment, the light extraction section 510 includes a convex structure 500 that protrudes from the light emission area 502, and the convex structure 500 may be made of a resin tape or a resin seal.

[0084] In the organic EL light-emitting apparatus of the above-described embodiment, the light-emitting region 402 (502) may be smoother than the light-extracting region 410 (510).

[0085] In the organic EL light-emitting apparatus of the above embodiment, an organic EL element 152 is provided, and on the light-emitting side surface of the light-emitting substrate 100, there is a second light-emitting region 403 in the portion facing the light-emitting region 123 of the organic EL element 152, and the non-light-emitting region 170 may be formed between the light-emitting region 402 and the second light-emitting region 403 when the light-emitting substrate 100 is viewed from above.

[0086] In the organic EL light-emitting device of the embodiment described above, the organic EL element 151 and the organic EL element 152 (second organic EL light-emitting element) may have different light-emitting colors in the light-emitting region 123 when lit.

[0087] In the organic EL light-emitting apparatus of the above-described embodiment, the refractive index of the light-emitting substrate 100 may be smaller than the refractive index near the interface between the organic EL element 151 and the light-emitting substrate 100.

[0088] In the organic EL light-emitting apparatus of the above-described embodiment, the refractive index of the light-emitting substrate 100 may be smaller than the refractive index of the portion of the organic EL element 151 that is on the light-emitting side of the light-emitting region 123.

[0089] In the organic EL light-emitting apparatus of the above-described embodiment, the refractive index of the light-emitting substrate 100 may be greater than 1.

[0090] Figure 11 shows an experimental example confirming the visibility when a concave structure is provided on the light-emitting side of the substrate constituting an organic EL panel.

[0091] Figure 11 is a photograph of a fully emitting organic EL panel viewed from the light-emitting side of the substrate. Figure 11 shows that within a square panel represented by dimensions 801 (the entire area of ​​the organic EL element), a smaller square area represented by dimensions 802 (the light-emitting area of ​​the organic EL element) is emitting light. In Figure 11, within the area of ​​the panel represented by dimensions 801, the area other than the area represented by dimensions 802 is a non-emitting area and appears black in the photograph. This organic EL panel is made using a glass substrate.

[0092] Here, mimicking the concave structure 400 in Figures 4, 5, and 8, the scratches (scribe lines) made on the light-emitting side of the substrate by the scribe method are the scribe lines 803 (multiple lines indicated by arrows) in Figure 11. As can be seen from this photograph, the scribe lines 803 are visible as bright, luminous lines. Scrib lines formed in the non-luminescent region are also visible as luminous lines against the black background. As described above, this means that the light emitted from the organic layers 121 and 122 of the organic EL elements 151 and 152, and the substrate-mode light, are reflected, transmitted, and scattered at the concave scribe lines, and are extracted to the emission side of the substrate. This shows that the present invention is an effective method for making non-luminescent regions invisible. Furthermore, by allowing substrate-mode light, which would normally not be extracted outside the substrate due to total internal reflection, to be extracted outside the substrate, the light generated in the organic layers 121 and 122 in Figures 2 to 10 can be utilized more effectively, contributing to improved luminous efficiency.

[0093] 100: Substrate 110: Lower electrode 111: Lower electrode of color 1 112: Lower electrode of color 2 120: Organic layer 121: Organic layer of color 1 122: Organic layer of color 2 123: Light-emitting region 130: Upper electrode 131: Upper electrode of color 1 132: Upper electrode of color 2 140: Sealing layer 150: Organic EL element 151: Organic EL element of color 1 152: Organic EL element of color 2 160: Cross-sectional view of stripe pair of color 1 and color 2 (organic EL element) 170: Stripe spacing of color 1 and color 2 (non-light-emitting region) 180: External air layer 200: Organic EL panel emitting light in a planar manner 201: Organic EL panel emitting light in a stripe pattern 300: Light transmitted from the substrate to the external air layer 301: Substrate mode light that does not transmit to the external air layer but propagates within the substrate in the direction of the substrate plane 400: Concave structure 401: Organic EL panel 402, 403: Light emission area 405, 406: Inclined surface 410: Light extraction section 500: Convex structure 501: Organic EL panel 502, 503: Light emission area 505: Arc surface 510: Light extraction section 600: Light transmitted from the concave structure to the outside of the substrate 700: Light transmitted from the convex structure to the outside of the substrate 801: Entire area of ​​the organic EL element 802: Light-emitting area of ​​the organic EL element 803: Scrib line (concave structure)

Claims

1. An organic EL light-emitting device comprising an organic EL light-emitting element and a light-emitting substrate, wherein the light-emitting substrate is provided on the light-emitting side of the organic EL light-emitting element, the surface of the light-emitting substrate on the light-emitting side has a light-emitting region in a portion facing the light-emitting region of the organic EL light-emitting element, the light-emitting substrate has a non-light-emitting region when viewed from above, and a light extraction portion is provided at a position overlapping with the non-light-emitting region, and the light extraction portion includes a concave structure recessed with respect to the light-emitting region and / or a convex structure protruding with respect to the light-emitting region.

2. The organic EL light-emitting apparatus according to claim 1, wherein the non-emitting region extends in a predetermined direction, and the light extraction section extends along the direction of extension of the non-emitting region.

3. The organic EL light-emitting apparatus according to claim 1, wherein the light extraction section includes a concave structure recessed with respect to the light emission region, and the concave structure is linear or dotted.

4. The organic EL light-emitting apparatus according to claim 1, wherein the light extraction section includes a recessed structure recessed with respect to the light emission region, and the recessed structure has scribe marks.

5. The organic EL light-emitting apparatus according to claim 1, wherein the light extraction section includes a recessed structure recessed with respect to the light emission region, and the recessed structure has blast marks.

6. The organic EL light-emitting apparatus according to claim 1, wherein the light extraction section includes a recessed structure recessed with respect to the light emission region, and the recessed structure has etching marks.

7. The organic EL light-emitting apparatus according to claim 1, wherein the light extraction section includes a recessed structure recessed with respect to the light emission region, and the depth of the recessed structure is shallower than half the thickness of the light emission substrate.

8. The organic EL light-emitting apparatus according to claim 1, wherein the light extraction section includes a convex structure protruding from the light emission region, and the convex structure is made of a photocurable resin or a thermosetting resin.

9. The organic EL light-emitting apparatus according to claim 1, wherein the light extraction section includes a convex structure protruding from the light emission region, and the convex structure is made of a resin tape or a resin seal.

10. The organic EL light-emitting apparatus according to any one of claims 1 to 9, wherein the light-emitting region is smoother than the light-extracting section.

11. An organic EL light-emitting apparatus according to any one of claims 1 to 9, wherein the light-emitting side surface of the light-emitting substrate has a second light-emitting region in a portion facing the light-emitting region of the second organic EL light-emitting element, and the non-light-emitting region is formed between the light-emitting region and the second light-emitting region when the light-emitting substrate is viewed in plan view.

12. The organic EL light-emitting device according to claim 11, wherein the organic EL light-emitting element and the second organic EL light-emitting element have different light-emitting colors in their light-emitting regions when lit.

13. The organic EL light-emitting apparatus according to any one of claims 1 to 9, wherein the refractive index of the light-emitting substrate is smaller than the refractive index near the interface between the organic EL light-emitting element and the light-emitting substrate.

14. The organic EL light-emitting apparatus according to any one of claims 1 to 9, wherein the refractive index of the light-emitting substrate is smaller than the refractive index of the portion of the organic EL light-emitting element that is on the light-emitting side of the light-emitting region.

15. The organic EL light-emitting apparatus according to any one of claims 1 to 9, wherein the refractive index of the light-emitting substrate is greater than 1.

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