JP2006278258A - Organic light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic light-emitting device that can achieve miniaturizing and high performance. <P>SOLUTION: The organic light-emitting device, after white light generated from an organic layer 163 is resonated between lower electrode layers 161R, 161G, 161B and an upper electrode layer 164, is provided with a red organic EL element 16R, a green organic EL element 16G, and a blue organic EL element 16B to discharge a red light HR, a green light HG, and a blue light HB through an upper electrode layer 164, respectively. The reflectivity S1G of the lower electrode layer 161G of the green organic EL element 16G is smaller than the reflectivity S1R of the lower electrode layer 161R of the red organic EL element 16R (S1G<S1R). The chromaticity of the green light HG stabilizes since the variation in the chromaticity thereof caused by the variation in the optical distance LG hardly occurs. There is no need for installing the color filter since the chromaticity of the green light HG stabilizes even if the color filter is not used. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic light emitting device using an organic electroluminescence (EL) phenomenon.

  In recent years, a display that displays an image using an organic EL phenomenon (so-called organic EL display) has attracted attention as one of flat panel displays. Since this organic EL display is a self-luminous display that displays an image by utilizing the light emission phenomenon of the organic EL element, it is excellent in that the viewing angle is wide and the power consumption is small.

  The organic EL display mainly has a structure in which a driving panel and a sealing panel are arranged to face each other, and the driving panel and the sealing panel are bonded to each other through an adhesive layer. The drive panel is provided with a plurality of thin film transistors (TFTs) and a plurality of organic EL elements for image display on one surface of a substrate. This organic EL element has a structure in which a layer including a light emitting layer is provided between a lower electrode layer and an upper electrode layer, and the layer including the light emitting layer is used together with a light emitting layer as a light generation source. It includes a hole transport layer and an electron transport layer.

  With regard to this organic EL display, several modes have already been proposed for the purpose of improving display performance.

Specifically, for example, the organic EL element is configured to include a light-reflective lower electrode layer and a light semi-transmissive upper electrode layer, and light generated from the light-emitting layer is transmitted to the lower electrode layer and the upper electrode layer. An organic EL display that emits light after being resonated by being reflected between them (having a so-called optical resonance function) is known (for example, see Patent Document 1). The element structure of the organic EL element responsible for this optical resonance function is generally called a “resonator structure”, and functions as a kind of narrow band filter. In an organic EL display including an organic EL element having this resonator structure, for example, a lower electrode layer and an upper electrode between a plurality of organic EL elements that emit light of different colors (for example, red, green, and blue). The distances between the layers (so-called optical distances) are different from each other. Specifically, the optical distance of each organic EL element is set according to the wavelength of each color. In this type of organic EL display, the light emission efficiency is improved for each color based on the optical resonance action of the resonator structure, so that the color purity is improved for each color.
JP 2003-142277 A

Further, for example, as an organic EL display including the organic EL element having the resonator structure described above, the organic EL display is disposed corresponding to a plurality of organic EL elements that emit light of different colors (for example, red, green, and blue). An organic EL display including a color filter having filter regions of colors (for example, red, green, and blue) corresponding to each color of the light is known (see, for example, Patent Document 2). In this type of organic EL display, since the light emitted from each organic EL element is emitted through a color filter, the color purity of each color is improved and the reflected light generated inside the organic EL display is colored. Since it is absorbed by the filter, the contrast is secured.
International Publication No. WO01 / 39554 Pamphlet

  By the way, with the recent recognition of the practicality of organic EL displays, not only large displays such as monitors, but also small displays typified by viewfinders, more specifically, a pixel pitch of several μm Attempts have been made to apply organic EL displays to the required small displays. In this case, when applying the organic EL display to a small display, for example, in order to differentiate it from the current liquid crystal display in terms of the external size and display performance, the display performance is reduced while minimizing the display size as much as possible. It is necessary to improve the performance as much as possible.

  However, the conventional organic EL display is still not sufficient in terms of realizing miniaturization and high performance in accordance with market demands, so there is much room for improvement. Accordingly, in order to prove the usefulness of the organic EL display and to promote the market, it is desired to establish a technique capable of realizing a reduction in size and performance of the organic EL display.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an organic light-emitting device capable of realizing miniaturization and high performance.

  The organic light emitting device according to the present invention has a structure in which a layer including a light emitting layer is provided between a first electrode layer and a second electrode layer, and light generated from the light emitting layer is emitted from the first electrode layer. A red organic light emitting device, a green organic light emitting device, and a blue organic light emitting device that resonate between the first electrode layer and the second electrode layer and then emits red light, green light, and blue light through the second electrode layer, respectively. And a layer including a light emitting layer generates light of a common color among the red organic light emitting element, the green organic light emitting element, and the blue organic light emitting element from the light emitting layer, and the red organic light emitting element, the green organic Shared by the light emitting device and the blue organic light emitting device, and the distance between the first electrode layer and the second electrode layer is emitted from the red organic light emitting device, the green organic light emitting device, and the blue organic light emitting device, respectively. Depending on the color of light The red organic light emitting element, the green organic light emitting element and the blue organic light emitting element are different from each other, and the reflectance of the first electrode layer of the green organic light emitting elements is the first of the red organic light emitting elements. It is smaller than the reflectance of one electrode layer.

  In the organic light emitting device according to the present invention, after the common light generated from the light emitting layer is resonated between the first electrode layer and the second electrode layer, red light is respectively transmitted through the second electrode layer, When a red organic light emitting element that emits green light and blue light, a green organic light emitting element, and a blue organic light emitting element are provided, the reflectance of the first electrode layer of the green organic light emitting element is that of the red organic light emitting element. Since the reflectance of the first electrode layer is smaller than the reflectance of the first electrode layer of the red organic light emitting element, the reflectance of the first electrode layer of the green organic light emitting element is equal to or higher than the reflectance of the first electrode layer of the red organic light emitting element. In comparison with the case of the above, the chromaticity of the green light is less likely to vary due to the variation in the distance between the first electrode layer and the second electrode layer (so-called optical distance), that is, the green color Stabilizes the chromaticity of light. In this case, for example, as a resonance condition, a relational expression of (2L) / λ + Φ / (2π) = m (“L” is a distance (optical distance) between the first electrode layer and the second electrode layer) , “Λ” is the peak wavelength of the spectrum of light emitted from the red organic light emitting device, the green organic light emitting device, and the blue organic light emitting device, and “Φ” is the light emitted from the light emitting layer from the first electrode layer and the second organic light emitting device. When the phase shift generated when reflecting on the electrode layer, “m” represents 0 or an integer, respectively), the value of m in the above relational expression in the red organic light-emitting element is m = If the condition of 0 is satisfied, even if the value of m is set to the minimum, a sufficient resonance action can be obtained in the red organic light emitting element, so that the chromaticity of the red light emitted from the red organic light emitting element Will improve. Moreover, in this case, the chromaticity of green light is stabilized and the color purity of red light is improved without using a color filter, so that it is not necessary to mount the color filter.

  According to the organic light emitting device of the present invention, the light of the common color generated from the light emitting layer is resonated between the first electrode layer and the second electrode layer, and then passed through the second electrode layer. When a red organic light emitting element that emits red light, green light, and blue light, a green organic light emitting element, and a blue organic light emitting element are provided, the reflectance of the first electrode layer of the green organic light emitting element is red. The chromaticity of the green light is stabilized based on the structural feature that is smaller than the reflectance of the first electrode layer of the organic light emitting device. In this case, for example, by optimizing the resonance condition (value of m) of the red organic light emitting element (m = 0), the color purity of red light is improved. In addition, in this case, since the chromaticity of green light is stabilized and the color purity of red light is improved without using a color filter, the size is reduced by the amount not equipped with the color filter. Therefore, even when the outer size is reduced, the image display performance is ensured, so that downsizing and higher performance can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, the configuration of an organic EL display as an organic light-emitting device according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a cross-sectional configuration of an organic EL display. 2 and 3 schematically show an enlarged cross-sectional configuration of the main part of the organic EL display shown in FIG. 1, and FIG. 2 shows a red organic EL element 16R and a green organic EL element 16G. , Blue organic EL element 16B, and FIG. 3 shows organic layer 163.

  The organic EL display according to the present embodiment displays an image using an organic EL phenomenon. For example, as shown in FIG. 1, three different colors of light as image display light H, That is, three organic ELs that emit red (R) light (red light) HR, green (G) light (green light) HG, and blue (B) light (blue light) HB, respectively. An element 16 (red organic EL element 16R, green organic EL element 16G, blue organic EL element 16B) is provided. More specifically, the organic EL display has a structure in which the drive panel 10 and the sealing panel 20 are arranged to face each other, and the drive panel 10 and the sealing panel 20 are bonded to each other via the adhesive layer 30. ing. This organic display has, for example, a top emission type structure that displays an image by emitting light H for image display upward, that is, through the sealing panel 20 to the outside.

  The driving panel 10 includes, for example, a thin film transistor (TFT) 12, an interlayer insulating layer 13, a driving wiring 14, a planarizing insulating layer 15, and the organic EL element 16 (red organic EL) on one surface of a driving substrate 11. The element 16R, the green organic EL element 16G, the blue organic EL element 16B), the auxiliary wiring 17, the in-layer insulating layer 18, and the protective layer 19 are stacked in this order (from the side closer to the driving substrate 11). It has a structure.

  The driving substrate 11 supports a series of components such as the TFT 12 and the organic EL element 16 and is made of, for example, a non-light-transmissive insulating material such as silicon (Si) or plastic.

  The TFTs 12 emit light by driving the organic EL elements 16. For example, a plurality of TFTs 12 are arranged in a matrix on one surface of the driving substrate 11. The TFT 12 is electrically connected to the drive wiring 14 through a contact hole (not shown) provided in the interlayer insulating layer 13. The structure of the TFT 12 is not particularly limited, and may be, for example, a bottom gate type structure or a top gate type structure.

The interlayer insulating layer 13 electrically isolates the TFT 12 from the surroundings, and is made of an insulating material such as silicon oxide (SiO ₂ ) or PSG (phospho-silicate glass). The interlayer insulating layer 13 is disposed so as to cover, for example, the TFT 12 and the driving substrate 11 around it.

  The drive wiring 14 drives the organic EL element 16 by functioning as a signal line, and is made of, for example, a conductive material such as aluminum (Al) or aluminum copper alloy (AlCu). The drive wiring 14 is electrically connected to the organic EL element 16 through a contact hole (not shown) provided in the planarization insulating layer 15. For example, two drive wirings 14 are provided for each TFT 12 (gate signal line, drain signal line), and are electrically connected to the TFT 12 as described above.

The planarization insulating layer 15 electrically isolates between the TFT 12 and the drive wiring 14 and the organic EL element 16, and planarizes the base on which the organic EL element 16 is disposed. For example, silicon oxide It is made of an insulating material such as (SiO ₂ ). Although not shown in FIG. 1, in the planarization insulating layer 15, for example, a capacitor for driving the TFT 12 and an electrical connection between the drive wiring 14 and the organic EL element 16 are used. Multi-level wiring is buried.

  The organic EL element 16 is an organic light emitting element that emits light H for image display using an organic EL phenomenon. For example, as described above, red light that emits red light HR (for example, wavelength = about 630 nm). The organic EL element 16R includes a green organic EL element 16G that emits green light HG (for example, wavelength = 530 nm), and a blue organic EL element 16B that emits blue light HB (for example, wavelength = 460 nm). The red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B are arranged in the arrangement pattern of the TFT 12 with the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B as one set. Correspondingly, a plurality of sets are arranged in a matrix.

The organic EL element 16 (red organic EL element 16R, green organic EL element 16G, blue organic EL element 16B) includes, for example, lower electrode layers 161R, 161G, 161B and upper electrode layer 164 as shown in FIG. More specifically, the organic layer 163 is provided between the lower electrode layers 161R, 161G, and 161B, the transparent conductive layers 162R, 162G, and 162B, the organic layer 163, and the upper electrode layer. 164 has a stacked structure in which these layers are stacked in this order (from the side closer to the planarization insulating layer 15). In particular, the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B reflect light generated from the organic layer 163 between the lower electrode layers 161R, 161G, and 161B and the upper electrode layer 164. It has a resonator structure that resonates, and all function as a kind of narrow band filter. The distance (optical distance) between the lower electrode layers 161R, 161G, and 161B and the upper electrode layer 164 is a factor that contributes to the resonance characteristics of the resonator structure described above. For example, the following relational expression (1) Satisfies the relationship.
(2L) / λ + Φ / (2π) = m (1)
(However, “L” is an optical distance between the lower electrode layers 161R, 161G, 161B and the upper electrode layer 164, and “λ” is from the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. The peak wavelength of the spectrum of the emitted light, “Φ” is a phase shift that occurs when the light generated from the organic layer 163 is reflected by the lower electrode layers 161R, 161G, 161B and the upper electrode layer 164, “m” is 0 or Each represents an integer.)

  More specifically, for convenience, when the stacked structures of the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B are separated from each other, the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element are separated. The laminated structure of 16B is shown as shown in FIG.

That is, the red organic EL element 16R includes a lower electrode layer 161R (thickness KR), a transparent conductive layer 162R (thickness DR), an organic layer 163 (thickness YR), and an upper electrode layer 164 (thickness JR). Have a stacked structure in which the layers are stacked in this order. The red organic EL element 16R has, for example, a resonator structure for emitting red light HR, and more specifically, light generated from the organic layer 163 is emitted from the lower electrode layer 161R and the upper electrode layer. After resonating with 164, the red light HR is emitted through the upper electrode layer 164. The distance (optical distance) between the lower electrode layer 161R and the upper electrode layer 164 satisfies the relationship of the following relational expression (2). Here, for example, mR = 0 in the relational expression (2), that is, the relational expression (2) satisfies the relation of the following relational expression (3).
(2LR) / λR + Φ / (2π) = mR (2)
(2LR) / λR + Φ / (2π) = 0 (3)
(However, “LR” means lower electrode layer 161R (end surface PR1 adjacent to transparent conductive layer 162R in lower electrode layer 161R) and upper electrode layer 164 (end surface PR2 adjacent to organic layer 163 in upper electrode layer 164). ) “ΛR” is the peak wavelength of the spectrum of the light emitted from the red organic EL element 16R, “Φ” is the light generated from the organic layer 163, and the lower electrode layer 161R (end face PR1) and (The phase shift "mR" generated when the light is reflected on the upper electrode layer 164 (end face PR2) represents 0 or an integer.)

The green organic EL element 16G includes a lower electrode layer 161G (thickness KG), a transparent conductive layer 162G (thickness DG), an organic layer 163 (thickness YG), and an upper electrode layer 164 (thickness JG). It has a laminated structure laminated in this order. The green organic EL element 16G has, for example, a resonator structure for emitting green light HG. More specifically, the light generated from the organic layer 163 is emitted from the lower electrode layer 161G and the upper electrode layer. After resonating with 164, it is emitted as green light HG through the upper electrode layer 164. The distance (optical distance) between the lower electrode layer 161G and the upper electrode layer 164 satisfies the relationship of the following relational expression (4). Here, for example, mG = 0 in the relational expression (4), that is, the relational expression (4) satisfies the relation of the following relational expression (5). In relational expression (4), for example, not only mG = 0 as described above, but also mG = 1 may be used.
(2LG) / λG + Φ / (2π) = mG (4)
(2LG) / λG + Φ / (2π) = 0 (5)
(However, “LG” refers to the lower electrode layer 161G (end surface PG1 adjacent to the transparent conductive layer 162G in the lower electrode layer 161G) and the upper electrode layer 164 (end surface PG2 adjacent to the organic layer 163 in the upper electrode layer 164). ) “ΛG” is the peak wavelength of the spectrum of the light emitted from the green organic EL element 16G, “Φ” is the light generated from the organic layer 163 and the lower electrode layer 161G (end face PG1) and (The phase shift “mG” generated when the light is reflected on the upper electrode layer 164 (end surface PG2) represents 0 or an integer.)

The blue organic EL element 16B includes a lower electrode layer 161B (thickness KB), a transparent conductive layer 162B (thickness DB), an organic layer 163 (thickness YB), and an upper electrode layer 164 (thickness JB). It has a laminated structure laminated in this order. The blue organic EL element 16B has, for example, a resonator structure for emitting blue light HB. More specifically, the light generated from the organic layer 163 is emitted from the lower electrode layer 161B and the upper electrode layer. After resonating with 164, it is emitted as blue light HB through the upper electrode layer 164. The distance (optical distance) between the lower electrode layer 161B and the upper electrode layer 164 satisfies the relationship of the following relational expression (6). Here, for example, mB = 1 in the relational expression (6), that is, the relational expression (6) satisfies the relation of the following relational expression (7). In relational expression (6), for example, not only mB = 1 as described above, but also mB = 0 may be used.
(2LB) / λB + Φ / (2π) = mB (6)
(2LB) / λB + Φ / (2π) = 1 (7)
(However, “LB” refers to the lower electrode layer 161B (end surface PB1 adjacent to the transparent conductive layer 162B of the lower electrode layer 161B) and the upper electrode layer 164 (end surface PB2 adjacent to the organic layer 163 of the upper electrode layer 164). ) “ΛB” is the peak wavelength of the spectrum of light emitted from the blue organic EL element 16B, “Φ” is the light generated from the organic layer 163, and the lower electrode layer 161B (end face PB1) and (The phase shift that occurs when reflecting on the upper electrode layer 164 (end face PB2), “mB” represents 0 or an integer, respectively.)

  The optical distances LR, LG, and LB are the colors of light emitted from the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B (red of the red light HR, green of the green light HG, blue light, respectively). The red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B are different from each other according to the blue color of HB. Specifically, the optical distances LR, LG, and LB indicate the light emitted from the organic layer 163 by the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, respectively, as red light HR, green light HG, and For example, as shown in the above relational expressions (3), (5), and (7), mR = 0, mG = 0, and mB = 1. In this case, the light intensity decreases in order corresponding to blue light HB, red light HR, and green light HG (LB> LR> LG). The above-mentioned “emitting the light generated from the organic layer 163 as red light HR, green light HG, and blue light HB” means that any light emitting point NR, NG, In the process in which light generated in the NB is resonated between the lower electrode layers 161R, 161G, 161B and the upper electrode layer 164 and then emitted through the upper electrode layer 164, the red organic EL element 16R and the green organic EL element 16G And the blue organic EL element 16B using the multiple interference phenomenon of light based on the difference in resonance length (optical distances LR, LG, LB), the same when generated at the light emitting points NR, NG, NB. When the wavelength of light having a color (wavelength) is emitted, the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B are mutually connected. By selectively increasing the wavelength corresponding to red in the red organic EL element 16R, the wavelength corresponding to green in the green organic EL element 16G, and the wavelength corresponding to blue in the blue organic EL element 16B, respectively, This means that red light HR, green light HG, and blue light HB are finally generated.

  The lower electrode layers 161R, 161G, and 161B function as electrodes for applying a voltage to the organic layer 163, and also function as mirrors (total reflection mirrors) that reflect the light generated from the organic layer 163 to resonate. As shown in FIG. 1, the first electrode layer is arranged separately from each other for each arrangement region of the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. Here, for example, the lower electrode layer 161R and the lower electrode layer 161G are made of the same material, and the lower electrode layer 161R and the lower electrode layer 161G have different thicknesses KR and KG. (KR ≠ KG). These lower electrode layers 161R and 161G are made of an electrode material having light reflectivity. For example, all of them are made of aluminum (Al), an alloy containing aluminum, silver (Ag), or an alloy containing silver. Yes. This “alloy containing aluminum” is a so-called alloy containing aluminum as a main component, and examples thereof include an aluminum neodymium alloy (AlNd; for example, Al: Nd = 90 wt%: 10 wt%). The “silver-containing alloy” is an alloy containing so-called silver as a main component, for example, a silver palladium copper alloy (AgPdCu; for example, Ag: Pd: Cu = 99 weight: 0.75 weight%: 0.25). % By weight).

  Specifically, the thickness KG of the lower electrode layer 161G is smaller than the thickness KR of the lower electrode layer 161R (KG <KR). With the difference between the thicknesses KR and KG, the lower electrode layer 161G The reflectance S1G of 161G is smaller than the reflectance S1R of the lower electrode layer 161R (S1G <S1R). In particular, the reflectance S1R of the lower electrode layer 161R and the reflectance S1G of the lower electrode layer 161G are both about 60% or more (S1R, S1G ≧ 60%), more specifically, a range of about 60% or more and 100% or less. (60% ≦ S1R, S1G ≦ 100%). Further, the difference of the reflectance S1G of the lower electrode layer 161G with respect to the reflectance S1R of the lower electrode layer 161R is about 10% or more. “The difference between the reflectance S1G and the reflectance S1R is about 10% or more” means that when the reflectance S1R is used as a reference, the reflectance S1G has a value of about 10 more than the reflectance S1R. In other words, the value of the reflectance S1G is about 90% or less of the value of the reflectance S1R (SG ≦ SR × 0.9).

  The thickness KB, material, and reflectance S1B of the lower electrode layer 161B can be freely set according to the thickness KR, KB, material, and reflectances S1R, S1G of the lower electrode layers 161R, 161G. However, the reflectance S1B of the lower electrode layer 161B is, for example, about 60% or more (S1B ≧ 60%), more specifically, similar to the reflectance S1R of the lower electrode layer 161R and the reflectance S1G of the lower electrode layer 161G. Is in the range of about 60% to 100% (60% ≦ S1B ≦ 100%). In FIG. 2, for example, the lower electrode layer 161B is made of the same material as that of the lower electrode layers 161R and 161G, and the thickness KB of the lower electrode layer 161B is set to the thickness KG of the lower electrode layer 161G. Along with the coincidence (K1B = K1G), the reflectance S1B of the lower electrode layer 161B coincides with the reflectance S1G of the lower electrode layer 161G (S1B = S1G), and the reflectance S1R of the lower electrode layer 161R. The difference in the reflectance S1B of the lower electrode layer 161B with respect to is similar to the difference in the reflectance S1G of the lower electrode layer 161G with respect to the reflectance S1R of the lower electrode layer 161R.

  The transparent conductive layers 162R, 162G, and 162B substantially function as electrodes by being adjacent to the lower electrode layers 161R, 161G, and 161B, and the red organic EL element 16R, the green organic EL element 16G, and the blue organic E element 16B. For example, as shown in FIG. 1, the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. Each of the arrangement regions is arranged separately from each other. These transparent conductive layers 162R, 162G, and 162B are each made of a transparent conductive material such as indium tin oxide (ITO). In particular, the thicknesses DR, DG, and DB of the transparent conductive layers 162R, 162G, and 162B are, for example, red light HR and green light emitted from the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, respectively. It differs corresponding to HG and blue light HB, and specifically decreases in the order of blue light HB, red light HR and green light HG (DB> DR> DG). The transparent conductive layers 162R, 162G, and 162B do not necessarily have to be made of the same transparent conductive material, for example, and may be made of different transparent conductive materials.

  The organic layer 163 emits light using an organic EL phenomenon. The organic layer 163 generates light of a specific color (wavelength range), that is, light of a common color (equal color) between the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. For example, white light is generated. In particular, as shown in FIG. 1, the organic layer 163 is a lower electrode layer arranged separately from each other in each arrangement region of the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. Unlike 161R, 161G, and 161B and transparent conductive layers 162R, 162G, and 162B, the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B extend while continuously passing through the respective arrangement regions. Are arranged as follows. That is, the organic layer 163 is shared by the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, and in each of the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. The thicknesses YR, YG, YB of the organic layer 163 are equal to each other (YR = YG = YB).

  The organic layer 163 includes, for example, a light emitting layer 1633 that generates light of a specific color by emitting light substantially using the organic EL phenomenon as shown in FIGS. 2 and 3. More specifically, the hole injection layer 1631, the hole transport layer 1632, the light emitting layer 1633, and the electron transport layer 1634 are stacked in this order (from the side closer to the lower electrode layers 161R, 161G, and 161B). It has a laminated structure. In order to generate white light as described above, for example, the red light emitting layer 1633R, the green light emitting layer 1633G, and the blue light emitting layer 1633B are arranged in this order (from the side closer to the hole transport layer 1632). ) Is laminated.

  The hole injection layer 1631 is for injecting holes into the hole transport layer 1632 and is made of, for example, 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine (MTDATA). Has been.

  The hole transport layer 1632 transports holes injected from the hole injection layer 1631 to the light emitting layer 1633, and is made of, for example, bis [(N-naphthyl) -N-phenyl] benzidine (α-NPD). Yes.

  Among the light emitting layers 1633, the red light emitting layer 1633R generates red light using an organic EL phenomenon. For example, 4-dicyanomethylene-6- (P-dimethylaminosityl) -2-methyl is used. It is composed of 8-quinolinol aluminum complex (Alq) mixed with about 2% by volume of 4H-pyran (DCM). The green light emitting layer 1633G generates green light using an organic EL phenomenon, and is made of, for example, an 8-quinolinol aluminum complex (Alq). The blue light emitting layer 1633B generates blue light using an organic EL phenomenon, and is made of, for example, bathocuproine (BCP).

  The electron transport layer 1634 transports electrons to the light emitting layer 1633 and is made of, for example, 8-quinolinol aluminum complex (Alq).

  The upper electrode layer 164 functions as an electrode for applying a voltage to the organic layer 163 and also functions as a half mirror that reflects the light generated from the organic layer 163 to resonate and then guides it to the outside. As shown in FIG. 1, as in the case of the organic layer 163, the red organic EL element 16 </ b> R, the green organic EL element 16 </ b> G, and the blue organic EL element 16 </ b> B are continuously passed through the respective arrangement regions. It is arranged to extend. That is, the upper electrode layer 164 is shared by the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, and each of the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. The thicknesses JR, JG, and JB of the upper electrode layer 164 in FIG. 6 are equal to each other (JR = JG = JB). The upper electrode layer 164 is made of a conductive material having light translucency, and has a single layer structure made of, for example, silver (Ag) or an alloy containing silver. This “alloy containing silver” is a so-called silver-containing alloy, for example, a silver magnesium alloy (AgMg; for example, Ag: Mg = 10 wt%: 90 wt%). In particular, the reflectance S2 of the upper electrode layer 164 is, for example, about 50% or more (S2 ≧ 50%), more specifically, about 50% or more and 95% or less (50% ≦ S2 ≦ 95%). is there. In this case, the reflectance S2 is, for example, preferably about 60% or more, and more preferably about 70% or more, or about 80% or more. When the reflectance S2 is smaller than about 50%, sufficient reflection characteristics cannot be obtained in the upper electrode layer 164. On the other hand, when the reflectance S2 is larger than about 95%, sufficient transmission characteristics are obtained in the upper electrode layer 164. It is because it cannot be obtained. Note that the upper electrode layer 164 does not necessarily have a single-layer structure, and may have a laminated structure made of different materials. More specifically, the upper electrode layer 164 includes, for example, a layer (lower layer) made of an alloy containing magnesium (Mg) and silver (Ag) and a layer (upper layer) made of an alloy containing silver or silver. And may have a two-layer structure laminated in this order. This “alloy containing magnesium and silver” is an alloy containing so-called magnesium and silver, for example, a magnesium silver alloy (MgAg; Mg: Ag = for example, 5 wt%: 1 wt% to 20 wt%: 1 wt. %). The “silver-containing alloy” is a so-called silver-containing alloy such as a silver magnesium alloy (AgMg; for example, Ag: Mg = 10 wt%: 90 wt%).

  The auxiliary wiring 17 reduces the resistance difference between the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B by relaxing the difference in resistance between the power source (not shown) and the upper electrode layer 164. And is electrically connected to the upper electrode layer 164. The auxiliary wiring 17 is disposed on the same level as the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. For example, the auxiliary wiring 17 does not include the organic layer 163 and the upper electrode layer 164, The red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B have substantially the same laminated structure (lower electrode layer / transparent conductive layer).

The in-layer insulating layer 18 electrically isolates between the organic EL element 16 and the auxiliary wiring 17, and in particular, red light emitted from the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. This is a bank for narrowing the emission range of HR, green light HG and blue light HB. The in-layer insulating layer 18 is made of, for example, an organic insulating material such as polyimide or polybenzoxazole, or an inorganic insulating material such as silicon oxide (SiO ₂ ). The red organic EL element 16R and the green organic EL Around the element 16G, the blue organic EL element 16B and the auxiliary wiring 17, the red organic EL element 16R, the green organic EL element 16G, the blue organic EL element 16B and the auxiliary wiring 17 are provided to be separated. .

  The protective layer 19 mainly protects the organic EL element 16 and is, for example, a passivation film made of a light transmissive dielectric material such as silicon nitride (SiN).

  On the other hand, the sealing panel 20 includes, for example, a sealing substrate 21. The sealing substrate 21 includes image display light H (red light HR, green light HG, red light HR, green light HG, red light EL element 16R, green organic EL element 16G, blue organic EL element 16B). The blue light HB) is transmitted to the outside of the organic EL display, and is made of, for example, a light-transmitting insulating material such as glass.

  The adhesive layer 30 is used to bond the drive panel 10 and the sealing panel 20 to each other, and is made of, for example, an adhesive material such as a thermosetting resin.

  Next, the operation of the organic EL display will be described with reference to FIGS.

  In this organic EL display, as shown in FIGS. 1 to 3, the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B are driven using the TFT 12 of the driving panel 10, that is, When a voltage is applied between the lower electrode layers 161R, 161G, 161B and the upper electrode layer 164, the light emitting layer 1633 of the organic layer 163 is supplied from the hole injection layer 1631 via the hole transport layer 1632. White light is generated by recombination of the generated holes and electrons supplied from the electron transport layer 1634. The white light is combined light (superimposed light) obtained by combining red light generated in the red light emitting layer 1633R, green light generated in the green light emitting layer 1633G, and blue light generated in the blue light emitting layer 1633B. It is.

  This white light is emitted from the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B as light H for image display to the outside of the organic EL display, and the red organic EL having a resonator structure. It is selectively enhanced by utilizing the multiple interference phenomenon of light based on the difference in resonance length (optical distance L (LR, LG, LB)) among the element 16R, the green organic EL element 16G, and the blue organic EL element 16B. That is, the red light HR, the green light HG, and the blue light HB are emitted from the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, respectively. Accordingly, the combined light (image display light H) of the red light HR, the green light HG, and the blue light HB emitted from the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, respectively, is an organic EL. Since it is visually recognized as an image by being emitted to the outside of the display, a full-color image is displayed based on the image display light H.

  In particular, when red light HR, green light HG, and blue light HB are emitted from the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, respectively, as shown in FIG. In the EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, the light generated from the light emitting layer 1633 of the organic layer 163 functions as a lower electrode layer 161R, 161G, 161B that functions as a total reflection mirror and a half mirror. Resonated by being reflected between the upper electrode layer 164 and the upper electrode layer 164. As a result, the half-value widths of the red light HR, the green light HG, and the blue light HB emitted from the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B are reduced. The color purity of the green light HG and the blue light HB is improved.

  In the organic EL display according to the present embodiment, when white light is generated from the organic layer 163, the white light is selectively used by utilizing the multiple interference phenomenon of light based on the difference in the optical distances LR, LG, and LB. It has a resonator structure that emits red light HR, green light HG, and blue light HB by enhancement and resonates by reflecting light between the lower electrode layers 161R, 161G, and 161B and the upper electrode layer 164. A red organic EL element 16R, a green organic EL element 16G, and a blue organic EL element 16B are provided, and in particular, the reflectance S1G of the lower electrode layer 161G of the green organic EL element 16G is lower electrode layer of the red organic EL element 16R. Since the reflectivity is smaller than the reflectivity S1R of 161R (S1G <S1R), downsizing and high performance are achieved for the following reasons. It can be realized.

  That is, when the reflectance S1G of the lower electrode layer 161G in the green organic EL element 16G is smaller than the reflectance S1R of the lower electrode layer 161R in the red organic EL element 16R (S1G <S1R), the reflectance Compared to the case where S1G is greater than or equal to the reflectance S1R (S1G ≧ S1R), variations in the optical distance LG, specifically, the film thicknesses of the transparent conductive layer 162G and the organic layer 163 that determine the optical distance LG, respectively. Since the chromaticity of the green light HG is less likely to vary due to the variation of the green light HG, the chromaticity of the green light HG is stabilized. This green light HG tends to vary in chromaticity due to variations in optical distance as compared with other red light HR and blue light HB. That is, the chromaticity of the green light HG is the red light HR. Considering that this is a factor that easily affects the chromaticity of the image display light H, which is a combined light of the green light HG and the blue light HB, the chromaticity of the green light HG is stabilized as described above. Accordingly, the chromaticity of the image display light H is similarly stabilized.

  In this case, for example, if the value of mR is set to 0 (mR = 0) as shown in the relational expressions (2) and (3) for determining the resonance condition of the red organic EL element 16R described above, for example. ) Even when the value of mR is set to the minimum, a sufficient resonance action is obtained in the red organic EL element 16R having the resonator structure, and therefore the color of the red light HR emitted from the red organic EL element 16R. The degree is improved. Specifically, when the value of mR is set to mR = 0, the red light HR is different from the case where the value of mR is set to a value other than mR = 0 (for example, when mR = 1 is set). In this spectrum, unnecessary spectral peaks that adversely affect the chromaticity of red (for example, higher-order components corresponding to the chromaticity of blue) are not generated, so that the color purity of the red light HR is improved.

  As a result, the chromaticity of the green light HG is stabilized and the color purity of the red light HR is improved. As a result, the chromaticity of the light H for image display is improved, so that image display performance is ensured.

  In this case, the chromaticity of the green light HG is stabilized and the color purity of the red light HR is improved without using a color filter, that is, the color filter is improved. Therefore, it is not necessary to mount a color filter in order to ensure the display performance of the image.

  Thereby, compared with the case where it is necessary to mount a color filter in order to ensure the display performance of the image, the display size is reduced by the amount that the color filter is not mounted, so that downsizing is realized.

  Therefore, in the present embodiment, even when the display size is reduced, the image display performance is ensured, so that downsizing and high performance can be realized.

  In the present embodiment, the reflectances S1R, S1G, and S1B of the lower electrode layers 161R, 161G, and 161B are about 60% or more (S1R, S1G, S1B ≧ about 60%), and the reflection of the upper electrode layer 164 is performed. Since the rate S2 is about 50% or more (S2 ≧ about 50%), the light reflectivity is sufficiently increased in both the lower electrode layers 161R, 161G, 161B and the upper electrode layer 164. In this case, light generated from the organic layer 163 is likely to be reflected by both the lower electrode layers 161R, 161G, 161B and the upper electrode layer 164, so that the light is likely to resonate. Accordingly, since sufficient resonance is obtained in the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, the color of the image display light H (red light HR, green light HG, blue light HB). Purity can be significantly improved.

  In the present embodiment, the difference between the reflectance S1G of the lower electrode layer 161G and the reflectance S1R of the lower electrode layer 161R is about 10% or more, that is, the reflectance S1G is about 10% or more with respect to the reflectance S1R. Since it was made small, sufficient difference is ensured between reflectance S1G and reflectance S1R. In this case, the chromaticity of the green light HG is less likely to vary due to the variation in the optical distance LG compared to the case where the difference in the reflectance S1G with respect to the reflectance S1R is less than about 10%. It becomes easier to stabilize the chromaticity of the green light HG. Therefore, the chromaticity of the green light HG can be remarkably stabilized.

  Here, the technical significance of the organic EL display of the present invention will be described. That is, the organic EL display of the present invention is mainly applied to a small display represented by a viewfinder and the like, and exhibits remarkable technical significance when applied to the small display. . In applications that apply to this type of small display, the display image must be sufficiently visible despite the small display size, so compared to applications that apply to large displays such as monitors. The display performance required for the organic EL display is inevitably high, that is, higher chromaticity characteristics are required than for the application applied to a large display. Moreover, in applications that are applied to small displays, the display size required for organic EL displays is inevitably reduced, reflecting the technical background that various electronic devices are required to be downsized recently. There is an increasing demand for reducing the display size. For these reasons, the technical significance of the organic EL display of the present invention is to achieve both downsizing the display and improving the display performance when the organic EL display is applied to a small display typified by a viewfinder. That is, the display performance is ensured while miniaturizing the display.

  In the present embodiment, as shown in FIG. 2, lower electrode layer 161R and lower electrode layer 161G are made of the same material, and lower electrode layer 161R and lower electrode layer 161G are mutually connected. The thicknesses KR and KG are different (KR ≠ KG, specifically KG <KR), and the reflectivity S1G of the lower electrode layer 161G is reduced by the difference between the thicknesses KR and KG. Although the reflectivity is smaller than the reflectivity S1R of 161R (S1G <S1R), the present invention is not necessarily limited thereto. Specifically, for example, as shown in FIG. 4 corresponding to FIG. 2, the lower electrode layer 161R and the lower electrode layer 161G are made of different materials (materials having different reflectances), and the material ( With the difference in reflectance, the reflectance S1G of the lower electrode layer 161G may be smaller than the reflectance S1R of the lower electrode layer 161R (S1G <S1R). The lower electrode layer 161G is made of a conductive material having a relatively low reflectance. For example, tungsten (W), chromium (Cr), molybdenum (Mo), titanium (Ti), tantalum (Ta), It is made of niobium (Nb) or nickel (Ni). The lower electrode layer 161R is made of a conductive material having a relatively high reflectivity, and is made of, for example, aluminum (Al), an alloy containing aluminum, silver (Ag), or an alloy containing silver. Yes. For example, FIG. 4 shows a case where the lower electrode layer 161R and the lower electrode layer 161G have the same thicknesses KR and KG (KR = KG). Note that the thickness KB, material, and reflectance S1B of the lower electrode layer 161B can be freely set. In FIG. 4, for example, the lower electrode layer 161B is made of the same material as that of the lower electrode layer 161G, and the thickness KB of the lower electrode layer 161B matches the thickness KG of the lower electrode layer 161G. As a result (KB = KG), the reflectance S1B of the lower electrode layer 161B matches the reflectance S1G of the lower electrode layer 161G (S1B = S1G). Also in this case, since the reflectance S1G of the lower electrode layer 161G is smaller than the reflectance S1R of the lower electrode layer 161R, the same operation as that described in the above embodiment can be obtained, so that the organic EL display Can be reduced in size and performance. The other configuration of the organic EL display shown in FIG. 4 is the same as that shown in FIG.

  Further, in the present embodiment, as shown in FIGS. 1 and 2, an image is displayed by emitting light H for image display upward, specifically through the sealing panel 20 to the outside. The organic EL display is configured to have a top emission type structure, but is not necessarily limited to this. For example, as shown in FIG. 5 and FIG. 6 corresponding to FIG. 1 and FIG. The organic EL display may be configured to have a bottom emission type structure in which an image is displayed by emitting the light H below, specifically through the drive panel 10 to the outside.

  In the organic EL display having the bottom emission structure, (1) the lower electrode layers 161R, 161G, and 161B are first electrode layers that function as mirrors, and the upper electrode layer 164 is a second electrode that functions as a half mirror. Unlike the above-described embodiment (see FIGS. 1 and 2) that is a layer, the lower electrode layers 161R, 161G, and 161B are second electrode layers that function as half mirrors, and the upper electrode layer 164 functions as a mirror. (2) The above-described embodiment in which the driving substrate 11 is made of a non-light-transmissive insulating material and the sealing substrate 21 is made of a light-transmissive insulating material. In contrast, the driving substrate 11 is made of a light transmissive insulating material, the sealing substrate 21 is made of a non-light transmissive insulating material, and (3) the upper electrode layer 64 extends continuously through the arrangement regions of the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, that is, the upper electrode layer 164 has the red organic EL element 16R, green Unlike the above-described embodiment shared by the organic EL element 16G and the blue organic EL element 16B, an upper electrode layer is provided for each arrangement region of the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. 164R, 164G, and 164B are arranged separately. The constituent materials of the lower electrode layers 161R, 161G, and 161B that function as half mirrors are the same as, for example, the constituent materials of the upper electrode layer 164 described in the above embodiment, and the upper electrode layers 164R and 164R that function as mirrors. The constituent materials of 164G and 164B are the same as the constituent materials of the lower electrode layers 161R, 161G, and 161B described in the above embodiment, for example. The constituent material (light-transmissive insulating material) of the driving substrate 11 is the same as the constituent material of the sealing substrate 21 described in the above embodiment, for example. The non-light-transmissive insulating material) is, for example, the same as the constituent material of the driving substrate 11 described in the above embodiment.

  In FIG. 6, for example, the upper electrode layer 164R and the upper electrode layer 164G are made of the same material, and the upper electrode layer 164R and the upper electrode layer 164G have different thicknesses JR and JG. (JR ≠ JG, specifically JG <JR), the reflectance S2G of the upper electrode layer 164G becomes smaller than the reflectance S2R of the upper electrode layer 164R with the difference between the thicknesses JR and JG. (S2G <S2R). The thickness JB, material, and reflectance S2B of the upper electrode layer 164B can be freely set. In FIG. 6, for example, the upper electrode layer 164B is made of the same material as that of the upper electrode layers 164R and 164G, and the thickness JB of the upper electrode layer 164B is equal to the thickness JG of the upper electrode layer 164G. Along with the coincidence (JB = JG), the reflectance S2B of the upper electrode layer 164B coincides with the reflectance S2G of the upper electrode layer 164G (S2B = S2G).

  Even in this case, since the reflectance S2G of the upper electrode layer 164G is smaller than the reflectance S2R of the upper electrode layer 164R, the same operation as that described in the above embodiment can be obtained. Miniaturization and high performance can be realized. The other configurations of the organic EL display shown in FIGS. 5 and 6 are the same as those shown in FIGS. That is, the relational expressions (1) to (7) described above regarding the organic EL display having the top emission type structure are similarly applied to the organic EL display having the bottom emission type structure.

  In the organic EL display having the bottom emission type structure shown in FIG. 6, for example, as shown in FIG. 7 corresponding to FIG. 4, the upper electrode layer 164R and the upper electrode layer 164G are made of different materials (reflectances to each other). May be configured such that the reflectance S2G of the upper electrode layer 164G is smaller than the reflectance S2R of the upper electrode layer 164R in accordance with the difference in the material (reflectance) (S2G < S2R). The constituent material of the upper electrode layer 164R is the same as the constituent material of the lower electrode layer 161R described above with reference to FIG. 4, and the constituent material of the upper electrode layer 164G is also described with reference to FIG. This is the same as the constituent material of the lower electrode layer 161G. In FIG. 7, for example, the case where the upper electrode layer 164R and the upper electrode layer 164G have the same thicknesses JR and JG (JR = JG) is shown. The thickness JB, material, and reflectance S2B of the upper electrode layer 164B can be freely set. In FIG. 7, for example, the upper electrode layer 164B is made of the same material as that of the upper electrode layer 164G, and the thickness JB of the upper electrode layer 164B matches the thickness JG of the upper electrode layer 164G. (JB = JG), the reflectance S2B of the upper electrode layer 164B matches the reflectance S2G of the upper electrode layer 164G (S2B = S2G). Also in this case, since the reflectance S2G of the upper electrode layer 164G is smaller than the reflectance S2R of the upper electrode layer 164R, the same operation as that described with reference to FIG. Can be reduced in size and performance. The configuration other than the above regarding the organic EL display shown in FIG. 7 is the same as that shown in FIG.

  Next, examples relating to the present invention will be described.

  Through the following procedure, the top emission type organic EL display described in the above embodiment with reference to FIGS. 1 to 3 (hereinafter simply referred to as “organic EL display of the present invention”) was manufactured.

  That is, first, a series of components (TFT 12, interlayer insulating layer 13, drive wiring 14, planarizing insulating layer 15) from the TFT 12 to the planarizing insulating layer 15 are sequentially formed on the glass driving substrate 11. After the lamination, aluminum (Al) is patterned on the planarization insulating layer 15 on the regions where the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B are respectively formed in a later step. Thus, lower electrode layers 161R, 161G, and 161B that function as mirrors were formed. In this case, by setting the thickness of the lower electrode layer 161R to 50 nm and the thicknesses of the lower electrode layers 161G and 161B to 13 nm, the reflectance S1R of the lower electrode layer 161R is 92% (reflectance S1R And the reflectances S1G and S1B of the lower electrode layers 161G and 161B were set to 70% (specific wavelengths of the reflectances S1G and S1B = 550 nm).

  Subsequently, transparent conductive layers 162R, 162G, and 162B were formed by pattern-forming ITO on the lower electrode layers 161R, 161G, and 161B, respectively.

  Subsequently, the surface of the transparent conductive layers 162R, 162G, and 162B is partially covered, and polyimide is formed in a pattern so as to fill the spaces between the transparent conductive layers 162R, 162G, and 162B. Layer 18 was formed. In this case, a cell for light emission was configured by exposing a central area (light emission area) of 2 mm × 2 mm square among the surface of each transparent conductive layer 162R, 162G, 162B.

Subsequently, each transparent conductive layer 162R, 162G, 162B and the in-layer insulating layer 18 are sequentially subjected to a film forming process using a vacuum deposition method in a vacuum atmosphere of 10 ⁻⁴ Pa or less to thereby form each transparent conductive layer. The organic layer 163 was formed so as to extend while continuously passing over the layers 162R, 162G, and 162B. When the organic layer 163 is formed, a hole injection layer 1631 (MTDATA, 10 nm thickness), a hole transport layer 1632 (α-NPD, 10 nm thickness), a light emitting layer 1633, and an electron transport layer 1634 (Alq, 15 nm thickness) are formed. In particular, a red light emitting layer 1633R (Alq mixed with 2% by volume of DCM, 15 nm thickness), a green light emitting layer 1633G (Alq, 15 nm thickness) and a blue light emitting layer 1633B (BCP, 15 nm thickness) are stacked. A light emitting layer 1633 was formed by stacking layers in this order.

  Subsequently, a magnesium silver alloy (MgAg, co-evaporation ratio (Mg: Ag) = 10: 1) is formed on the organic layer 163 to form a lower layer, and then silver (Ag) is formed on the lower layer. By forming an upper layer, an upper electrode layer 164 functioning as a half mirror was formed. In this case, the reflectance of the upper electrode layer 164 is set to 70% (specific wavelength of the reflectance S2 = 550 nm) by setting the thickness of the lower layer to 5 nm and the thickness of the upper layer to 30 nm. .

  Thereby, on the planarization insulating layer 15, red organic EL element 16R (lower electrode layer 161R / transparent conductive layer 162R / organic layer 163 / upper electrode layer 164), green organic EL element 16G (lower electrode layer 161G / transparent conductive). Layer 162G / organic layer 163 / upper electrode layer 164) and blue organic EL element 16B (lower electrode layer 161B / transparent conductive layer 162B / organic layer 163 / upper electrode layer 164). When the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B are formed, the organic layer 163 is particularly formed in the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. Resonance conditions were set so that light (white light) generated from the light was emitted as red light HR, green light HG, and blue light HB, respectively, that is, the wavelengths were maximized at 630 nm, 530 nm, and 460 nm, respectively. More specifically, as shown in the above relational expressions (2) to (7), mR = 0 in the red organic EL element 16R, mG = 0 in the green organic EL element 16G, and mB in the blue organic EL element 16B. = 1, transparent conductive layers 162R, 162G, and 162B have thicknesses DR, DG, and DB set to 56 nm, 28 nm, and 118 nm, respectively, and organic layers 163 have thicknesses YR, YG, and YB set to 80 nm did.

  Finally, after forming the drive panel 10 by forming the protective layer 19 on the upper electrode layer 164, the sealing panel 20 (sealing substrate 21) is bonded to the drive panel 10 using the adhesive layer 30. Thus, the organic EL display of the present invention was completed.

  When various performances of the organic EL display of the present invention were examined, the following series of results were obtained. When various performances of the organic EL display of the present invention are examined, in order to compare and evaluate the performance, the reflectance S1G of the lower electrode layer 161G is changed to the reflectance S1R (S1R = 92%) of the lower electrode layer 161R. Except for the point of equality (S1G = 92%), the same procedure as the manufacturing procedure of the organic EL display of the present invention is followed to give another organic EL display (hereinafter simply referred to as “comparative example organic EL display”). ) Was manufactured.

  First, when the color reproducibility of the organic EL display of the present invention was examined, the result shown in FIG. 8 was obtained. FIG. 8 shows the chromaticity characteristics (so-called chromaticity diagram) of the organic EL display of the present invention, where “horizontal axis” indicates chromaticity x and “vertical axis” indicates chromaticity y. “8A (solid line)” shown in FIG. 8 indicates the chromaticity characteristics of the organic EL display of the present invention, and “8B (dashed line)” indicates a liquid crystal display (LCD; liquid crystal) for current viewfinder use for reference. “8C (two-dot chain line)” indicates the chromaticity characteristic of the reference (monochromatic spectrum light) for reference.

  As can be seen from the results shown in FIG. 8, the organic EL display (8A) of the present invention has a chromaticity characteristic almost equal to that of the current LCD (8B) even though it does not have a color filter. . Therefore, in the organic EL display of the present invention, the color reproducibility comparable to the LCD of the current viewfinder application is achieved by making the reflectance S1G of the lower electrode layer 161G smaller than the reflectance S1R of the lower electrode layer 161R. It was confirmed that it was obtained.

  Subsequently, when the influence of the resonance condition on the chromaticity characteristics of the organic EL display of the present invention was examined, the result shown in FIG. 9 was obtained. FIG. 9 shows the resonance condition dependency of the red light spectrum, where the “horizontal axis” indicates the wavelength λ (nm) and the “vertical axis” indicates the spectrum intensity S (au). “9A (solid line)” and “9B (dashed line)” in FIG. 9 represent the difference in the value of mR in the above-described relational expression (2), and “9A” represents the case where mR = 0. “9B” indicates a case where mR = 1.

  As can be seen from the results shown in FIG. 9, when mR = 1 (9B), the spectrum intensity S is maximized in the vicinity of the wavelength λ = about 630 nm corresponding to red light, that is, the spectrum shows a peak. However, in this case, in addition to the wavelength λ corresponding to red light in the vicinity of about 630 nm, it corresponds to blue light, that is, blue light when the value of mB in the relational expression (6) is mB = 2. The spectrum also shows a peak in the vicinity of the wavelength λ = about 460 nm. This means that when mR = 1, not only a spectral peak corresponding to red light but also an unnecessary spectral peak (higher order component) corresponding to blue light is generated, so that it is emitted from the red organic EL element 16R. This indicates that the chromaticity characteristic of the red light HR deteriorates due to the presence of the above-described unnecessary spectral peak, that is, the chromaticity characteristic of the red light HR deviates from the desired chromaticity characteristic. In order to remove this unnecessary spectral peak (higher order component), for example, when the light absorption phenomenon of the color filter is used, when mR = 1, the color filter is used to control the chromaticity characteristics of the red light HR. Is indispensable. On the other hand, when mR = 0 (9A), unlike mR = 1, the spectrum shows a peak only in the vicinity of wavelength λ = about 630 nm corresponding to red light, and blue light The spectrum does not show a peak in the vicinity of the wavelength λ corresponding to 1 = about 460 nm. When mR = 0, only a spectral peak corresponding to red light is generated and an unnecessary spectral peak corresponding to blue light is not generated. Therefore, the color of the red light HR emitted from the red organic EL element 16R. This indicates that the chromaticity characteristic does not deteriorate due to the presence of the above-described unnecessary spectral peak, that is, the chromaticity characteristic of the red light HR matches the desired chromaticity characteristic. Accordingly, in the organic EL display of the present invention, the chromaticity characteristic of the red light HR emitted from the red organic EL element 16R can be obtained by setting mR = 0 in the relational expression (2). It was confirmed that control was possible to achieve desired chromaticity characteristics.

  Subsequently, when the influence of the reflectance on the chromaticity characteristics of the organic EL display of the present invention was examined, the results shown in FIGS. 10 and 11 were obtained. 10 and 11 show the reflectance dependency of the red light spectrum, FIG. 10 shows the dependency based on the reflectance S2 of the upper electrode layer 164 that functions as a half mirror, and FIG. 11 shows the lower portion that functions as a mirror. The dependence based on the reflectance S1R of the electrode layer 161R is represented. 10 and 11, the “horizontal axis” indicates the wavelength λ (nm), and the “vertical axis” indicates the spectrum intensity S (au). In FIG. 10, “10A (solid line)” and “10B (one-dot chain line)” represent the difference in reflectance S2, “10A” represents the case where reflectance S2 = 90%, and “10B” represents the reflectance. The case where S2 = 60% is shown. Further, “11A (solid line)” and “11B (one-dot chain line)” in FIG. 11 represent the difference in reflectance S1R, “11A” represents the case where reflectance S1R = 90%, and “11B” The case where reflectance S1R = 60% is shown.

  As can be seen from the results shown in FIG. 10, the half width of the spectrum between the case where the reflectance S2 of the upper electrode layer 164 is S2 = 90% (10A) and the case where S2 = 60% (10B). In addition, when comparing the spectral intensity S in the wavelength range corresponding to green (wavelength λ = 500 nm to 550 nm), when the reflectance S2 is relatively large (S2 = 90%), the half width of the spectrum is about While the spectral intensity S in the green wavelength region is reduced to about 4% (0.04 a.u.) with a decrease to 50 nm, the reflectance S2 is relatively reduced (S2 = 60%). ), The full width at half maximum of the spectrum increased to about 80 nm, and the spectral intensity S in the green wavelength region increased to about 10% (0.1 a.u.). This is because if the reflectance S2 is too small, the spectral half-value width increases and the spectral intensity in the green wavelength region also increases, so the chromaticity characteristics of the red light HR emitted from the red organic EL element 16R deteriorate. That is, the chromaticity characteristic of the red light HR deviates from the desired chromaticity characteristic. On the other hand, when the reflectance S2 is sufficiently large, the spectral half width is reduced and the spectral intensity in the green wavelength region is also reduced, so that the chromaticity characteristic of the red light HR emitted from the red organic EL element 16R is reduced. It indicates that there is no deterioration, that is, the chromaticity characteristic of the red light HR matches the desired chromaticity characteristic. Therefore, in the organic EL display of the present invention, the chromaticity characteristic of the red light HR emitted from the red organic EL element 16R is set to a desired chromaticity characteristic by sufficiently increasing the reflectance S2 of the upper electrode layer 164. It was confirmed that the control was possible. In this case, in particular, in order to satisfactorily control the chromaticity characteristics of the red light HR, the spectral half width and the spectral intensity in the green wavelength region shown in FIG. (S2 = 60%) and the spectral intensity in the green wavelength range is acceptable, the reflectance S2 of the upper electrode layer 164 is set to 60% or more (S2 ≧ 60%). ), It was confirmed that the chromaticity characteristics of the red light HR can be controlled well.

  Further, as can be seen from the results shown in FIG. 11, the spectrum of the spectrum between the case where the reflectance S1R of the lower electrode layer 161R is S1R = 90% (11A) and the case where S1R = 60% is set (11B). When comparing the spectral intensity S in the wavelength range corresponding to the full width at half maximum and green (wavelength λ = 500 nm to 550 nm), the reflectance is similar to the case described with respect to the reflectance S2 of the upper electrode layer 164 with reference to FIG. When S1R is relatively increased (S1R = 90%), the half-width of the spectrum is reduced to about 50 nm and the spectrum intensity S in the green wavelength region is about 4% (0.04 a.u.). In contrast, when the reflectance S1R is relatively small (S1R = 60%), the full width at half maximum of the spectrum becomes as large as about 70 nm and the green color is reduced. Spectrum of the intensity S in the long range is as large as about 8% (0.08a.u.). Therefore, in the organic EL display of the present invention, the chromaticity characteristic of the red light HR emitted from the red organic EL element 16R can be set to a desired chromaticity characteristic by sufficiently increasing the reflectance S1R of the lower electrode layer 161R. It was confirmed that the control was possible. In this case, in particular, in order to satisfactorily control the chromaticity characteristics of the red light HR, the spectral half width and the spectral intensity in the green wavelength region shown in FIG. 11, that is, the reflectance S1R of the lower electrode layer 161R is set to 60%. (S1R = 60%) and the spectral half-width in the green wavelength region is within the allowable range, the reflectance S1R of the lower electrode layer 161R is set to 60% or more (S1R ≧ 60%). ), It was confirmed that the chromaticity characteristics of the red light HR can be controlled well. Since the relationship between the allowable range relating to the red light HR and the chromaticity characteristics is obtained similarly for the green light HG and the blue light HB, the reflectance S1G of the lower electrode layer 161G and the reflectance S1B of the lower electrode layer 161B are obtained. By setting the ratio to 60% or more (S1G, S1B ≧ 60%), the chromaticity characteristics of the green light HG and the blue light HB can be controlled well.

  Subsequently, when the chromaticity characteristics of the organic EL display of the present invention and the chromaticity characteristics of the organic EL display of the comparative example were compared from the viewpoint of reproducibility, the results shown in Table 1 were obtained. Table 1 shows the chromaticity variation of the organic EL display of the present invention and the organic EL display of the comparative example. In Table 1, chromaticity variation (chromaticity) of green light HG (Green) emitted from the green organic EL element 16G (reflectance S1G (%) = 70%) of the organic EL display (present invention) of the present invention. The color of green light HG (Green) emitted from the green organic EL element 16G (reflectance S1G (%) = 92%) of the organic EL display (comparative example) of the comparative example is shown. Degree variation (chromaticity variation Δxy) is shown. In Table 1, for reference, the red light HR (Red) emitted from the red organic EL element 16R (reflectance S1R (%) = 92%) of the organic EL display of the present invention (the present invention) is shown. The chromaticity variation (chromaticity variation Δxy) is also shown. The above-described “chromaticity variation of the green light HG” means that when the thickness YG of the organic layer 163 is changed ± 5% in order to change the optical distance LG of the green organic EL element 16G, the green organic EL This is a range in which the chromaticity of the green light HG emitted from the element 16B varies. The “chromaticity variation of the red light HR” is a variation range of the chromaticity of the red light HR corresponding to the “chromaticity variation of the green light HG”.

  As can be seen from the results shown in Table 1, when the chromaticity variation Δxy of the green light HG is compared between the organic EL display of the present invention and the organic EL display of the comparative example, the chromaticity variation Δxy of the green light HG. Is the reflectance S1G of the lower electrode layer 161G than in the comparative example (S1G = S1R, Δxy = ± 0.108) in which the reflectance S1G of the lower electrode layer 161G is equivalent to the reflectance S1R of the lower electrode layer 161R. Is smaller in the case of the present invention (S1G <S1R, Δxy = ± 0.086), which is smaller than the reflectance S1R of the lower electrode layer 161R. This indicates that regarding the reflectance S1G of the lower electrode layer 161G in the green organic EL element 16G, if the reflectance S1G is sufficiently small, the chromaticity of the green light HG is less likely to vary. For reference, the chromaticity variation Δxy (Δxy = ± 0.016) of the red light HR related to the organic EL display of the present invention is the chromaticity variation Δxy (Δxy = ± 0. 086). That is, as apparent from the fact that the chromaticity variation Δxy of the green light HG tends to be significantly larger than the chromaticity variation Δxy of the red light HR, it is a combined light of the red light HR, the green light HG, and the blue light HB. Since the chromaticity variation Δxy of the green light HG tends to have a greater influence on the chromaticity of the light H for image display than the chromaticity variation Δxy of the red light HR, the chromaticity of the light H for image display. In order to control the image quality well, it is mainly derived that it is important to reduce the chromaticity variation Δxy of the green light HG as much as possible. From this, in the organic EL display of the present invention, it is confirmed that the chromaticity of the green light HG can be made difficult to vary by making the reflectance S1G of the lower electrode layer 161G smaller than the reflectance S1R of the lower electrode layer 161R. It was done.

  Then, when the detailed influence of the reflectance regarding the chromaticity characteristic of the organic electroluminescent display of this invention was investigated, the result shown in Table 2 was obtained. Table 2 shows the reflectance dependency of the chromaticity of the red light HR. The “reflectance S2” of the upper electrode layer 164 is changed in four steps of 63%, 80%, 88%, and 90%. In this case, “chromaticity x” and “chromaticity y” are shown.

  As can be seen from the results shown in Table 2, when the reflectance S2 of the upper electrode layer 164 of the red organic EL element 16R was changed from 63% to 90%, both chromaticity x and chromaticity y were reflected. As the rate S2 increased, it changed continuously. More specifically, the chromaticity x gradually increased and the chromaticity y gradually decreased. This indicates that the chromaticity (chromaticity x and chromaticity y) of the red light HR can change when the reflectance S2 changes. From this, it was confirmed that in the organic EL display of the present invention, the chromaticity of the red light HR can be controlled by changing the reflectance S2 of the upper electrode layer 164 of the red organic EL element 16R.

  Finally, based on the results shown in Table 2, the optimum range of the reflectance S2 of the upper electrode layer 164 functioning as a half mirror was examined, and the results shown in FIG. 12 were obtained. FIG. 12 shows the reflectance dependency of the chromaticity of the red light HR. The “horizontal axis” represents the reflectance S2 (%), and the “vertical axis” represents the chromaticity y of the red light HR. That is, the graph shown in FIG. 12 is a plot of the reflectance S2 and chromaticity y shown in Table 2.

  As can be seen from the results shown in FIG. 12, the chromaticity y of the red light HR gradually decreases as the reflectance S2 increases. In particular, the polarization point (the descending slope is large in the vicinity of the reflectance S2 = about 88%). Curves were drawn to have changing points). In this case, when securing the chromaticity characteristics of the red light HR, if the allowable range of chromaticity y is 0.36 or less and the appropriate range of chromaticity y is 0.35 or less, reflection Appropriate chromaticity y is satisfied when the ratio S2 is about 70% or more (S2 ≧ about 70%) and the reflectance S2 is about 80% or more (S2 ≧ about 80%). Meet the range. Therefore, in the organic EL display of the present invention, the reflectance S2 of the upper electrode layer 164 is further set to about 70% or more (S2 ≧ 70%), preferably about 80% or more (S2 ≧ 80%). It was confirmed that the chromaticity characteristics of the red light HR can be secured.

  As described above, the organic light emitting device of the present invention has been described with reference to the embodiments and examples. However, the present invention is not limited to the embodiments described in the above embodiments and examples, and as described above, the green organic EL element. Realizing downsizing and high performance of the organic light emitting device by making the reflectance S1G of the lower electrode layer 161G of 16G smaller than the reflectance S1R of the lower electrode layer 161R of the red organic EL element 16R However, the structure of the organic light emitting device can be freely changed as long as possible.

Specifically, for example, in the embodiments and examples described above, the optical distances LR, LG, and LB contributing to the resonance characteristics are set between the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B. In order to make them different from each other, the transparent conductive layers 162R, 162G, and 162B made of a transparent conductive material such as ITO are provided between the lower electrode layers 161R, 162G, and 161B and the organic layer 163. It is not limited to this. Specifically, for example, instead of the transparent conductive layers 162R, 162G, 162B, an insulating layer made of an insulating material such as silicon oxide (SiO ₂ ) may be provided. Even when this insulating layer is provided, in order to make the optical distances LR, LG, and LB different among the red organic EL element 16R, the green organic EL element 16G, and the blue organic EL element 16B, the thicknesses DR, DG Needless to say, the DBs must be different from each other. Even in this case, the same effects as those of the above-described embodiment and examples can be obtained.

  Further, for example, in the above-described embodiment and modification, as shown in FIG. 3, the hole injection layer 1631, the hole transport layer 1632, the light emitting layer 1633, and the electron transport layer 1634 have a four-layer structure laminated in this order. The organic layer 163 is configured as described above, and the light emitting layer 1633 is configured to have a three-layer structure in which the red light emitting layer 1633R, the green light emitting layer 1633G, and the blue light emitting layer 1633B are stacked in this order. However, the stacked structure (the number of stacked layers, the material (function) of each layer, etc.) of the organic layer 163 and the light emitting layer 1633 can be freely changed.

  The organic light emitting device according to the present invention can be applied to a small organic EL display such as a viewfinder, for example.

It is sectional drawing showing the cross-sectional structure of the organic electroluminescent display which concerns on one embodiment of this invention. It is sectional drawing which expands and represents typically the principal part (organic EL element) cross-sectional structure of the organic EL display shown in FIG. It is sectional drawing which expands and represents typically the cross-sectional structure of the other main part (organic layer) among the organic electroluminescent displays shown in FIG. It is sectional drawing showing the modification regarding the structure of the organic EL display (organic EL element) shown in FIG. It is sectional drawing showing the modification regarding the structure of the organic electroluminescent display which concerns on one embodiment of this invention. It is sectional drawing which expands and represents typically the cross-sectional structure of the principal part (organic EL element) of the organic EL display shown in FIG. It is sectional drawing showing the modification regarding the structure of the organic EL display (organic EL element) shown in FIG. It is a figure showing the chromaticity characteristic of the organic electroluminescent display of this invention. It is a figure showing the resonance condition dependence of the red light spectrum regarding the organic EL display of this invention. It is a figure showing the reflectance (reflectance of an upper electrode layer) dependence of the red light spectrum regarding the organic EL display of this invention. It is a figure showing the reflectance (reflectance of a lower electrode layer) dependence of the red light spectrum regarding the organic EL display of this invention. It is a figure showing the reflectance dependence of the chromaticity of the red light regarding the organic electroluminescent display of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Drive panel, 11 ... Drive board, 12 ... TFT, 13 ... Interlayer insulation layer, 14 ... Drive wiring, 15 ... Planarization insulation layer, 16 ... Organic EL element, 16B ... Blue organic EL element, 16G ... Green organic EL element, 16R ... red organic EL element, 17 ... auxiliary wiring, 18 ... insulating layer, 19 ... protective layer, 20 ... sealing panel, 21 ... sealing substrate, 30 ... adhesive layer, 161B, 161G, 161R ... lower electrode layer, 162B, 162G, 162R ... transparent conductive layer, 163 ... organic layer, 164, 164B, 164G, 164R ... upper electrode layer, 1631 ... hole injection layer, 1632 ... hole transport layer, 1633 ... light emitting layer, 1633B ... Blue light emitting layer, 1633G ... Green light emitting layer, 1633R ... Red light emitting layer, 1634 ... Electron transport layer, DB, JB, KB, YB, DG, JG, KG, YG, DR, J , KR, YR ... thickness, H ... light for image display, HB ... blue light, HG ... green light, HR ... red light, LB, LG, LR ... optical distance, NB, NG, NR ... light emitting point, PB1, PB2, PG1, PG2, PR1, PR2... End face.

Claims (14)

A structure including a light emitting layer is provided between the first electrode layer and the second electrode layer, and light generated from the light emitting layer is transmitted to the first electrode layer and the second electrode layer. A red organic light-emitting element, a green organic light-emitting element and a blue organic light-emitting element that emit as red light, green light and blue light through the second electrode layer, respectively,
The layer including the light emitting layer generates light of a common color among the red organic light emitting element, the green organic light emitting element, and the blue organic light emitting element from the light emitting layer, and the red organic light emitting element, green Shared by organic light emitting device and blue organic light emitting device,
The distance between the first electrode layer and the second electrode layer depends on the color of light emitted from the red organic light emitting device, the green organic light emitting device, and the blue organic light emitting device, respectively. The red organic light emitting device, the green organic light emitting device and the blue organic light emitting device are different from each other,
The organic light emitting device characterized in that the reflectance of the first electrode layer of the green organic light emitting element is smaller than the reflectance of the first electrode layer of the red organic light emitting element. . The first electrode layer of the green organic light emitting device and the first electrode layer of the red organic light emitting device are made of the same material and have different thicknesses. The organic light-emitting device according to claim 1. The first electrode layer of the green organic light emitting device and the first electrode layer of the red organic light emitting device are aluminum (Al), an alloy containing aluminum, silver (Ag), or an alloy containing silver. The organic light-emitting device according to claim 2, comprising: The organic material according to claim 1, wherein the first electrode layer of the green organic light emitting device and the first electrode layer of the red organic light emitting device are made of different materials. Light emitting device. The first electrode layer of the green organic light emitting device is tungsten (W), chromium (Cr), molybdenum (Mo), titanium (Ti), tantalum (Ta), niobium (Nb) or nickel (Ni). It consists of
The said 1st electrode layer of the said red organic light emitting element is comprised by the alloy containing aluminum (Al), the alloy containing aluminum, silver (Ag), or silver. Organic light emitting device. The organic light-emitting device according to claim 1, wherein the second electrode layer has a single-layer structure made of silver (Ag) or an alloy containing silver. The organic light-emitting device according to claim 1, wherein the second electrode layer has a stacked structure made of different materials. The second electrode layer is composed of an alloy containing magnesium (Mg) and silver (Ag) in this order from the side closer to the first electrode layer, and a layer made of an alloy containing silver or silver. The organic light-emitting device according to claim 7, having a two-layer structure in which and are stacked. The organic light-emitting device according to claim 1, wherein the reflectance of the first electrode layer is 60% or more. The difference in reflectance of the first electrode layer of the green organic light emitting device with respect to the reflectance of the first electrode layer of the red organic light emitting device is 10% or more. Item 10. The organic light-emitting device according to Item 9. The organic light-emitting device according to claim 1, wherein the reflectance of the second electrode layer is 50% or more. The organic light emitting device according to claim 1, wherein a distance between the first electrode layer and the second electrode layer is smaller in the green organic light emitting element than in the red organic light emitting element. . In the red organic light emitting device, the green organic light emitting device, and the blue organic light emitting device, the distance between the first electrode layer and the second electrode layer satisfies the following relational expression: The organic light-emitting device according to claim 1.
(2L) / λ + Φ / (2π) = m
(Where “L” is the distance (optical distance) between the first electrode layer and the second electrode layer, and “λ” is emitted from the red organic light emitting element, green organic light emitting element and blue organic light emitting element, respectively. The peak wavelength of the spectrum of the emitted light, “Φ” represents a phase shift that occurs when the light generated from the light emitting layer is reflected by the first electrode layer and the second electrode layer, and “m” represents 0 or an integer, respectively. ing.) The organic light-emitting device according to claim 13, wherein in the red organic light-emitting element, m in the relational expression satisfies a condition of m = 0.

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