JP2010211985A - Light-emitting device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device and an electronic equipment capable of restraining color shift due to differences of viewing angle. <P>SOLUTION: The device is provided with a light-emitting layer 40 pinched between an anode 10 with light transmittance and a cathode 11 with translucent reflectance, and a metal reflecting plate 15 arranged at an opposite side of the light-emitting layer 40 with the anode 10 in between. It is also provided with a light-emitting element 21 with a light resonation structure built for resonating emission light L1 emitted at the light-emitting layer 40 between the metal reflecting plate 15 and the cathode 11, as well as colored layers 37R, 37G, 37B into which light L2 irradiated from the light-emitting element 21 to face to light-emitting element 21 is incident. The colored layers 37R, 37G, 37B transmit light of a given wavelength region including light of a resonating wavelength at a viewing angle of 0° in the light resonation structure, and at the same time, absorb light at a side of a wavelength lower than the given wavelength region. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light emitting device and an electronic apparatus.

  In recent years, with the diversification of information equipment and the like, there is an increasing need for light-emitting devices that consume less power and are lighter. An organic electroluminescence device (organic EL device) is known as one of such light-emitting devices. Such an organic EL device generally includes a light emitting element having a light emitting layer between an anode (first electrode) and a cathode (second electrode). Furthermore, in order to improve the hole injection property and the electron injection property, a structure in which a hole injection / transport layer is disposed between the anode and the light emitting layer, or an electron injection layer or hole block between the light emitting layer and the cathode. A configuration in which layers are arranged has been proposed.

  However, the above-described organic EL device has a problem in that sufficient color reproducibility cannot be obtained when applied to a display device because the peak width of the spectrum of light extracted from the light emitting layer is wide and the light emission luminance is low. It was. Therefore, a light reflecting layer formed between the substrate and the anode, and a transflective cathode formed on the emission side of the light emitting layer, the light emitting layer between the light reflecting layer and the cathode There has been proposed a structure in which an optical resonator structure for resonating light emitted from the light source is provided.

  According to this configuration, the light emitted from the light emitting layer reciprocates between the light reflecting layer and the cathode, and only the light having the resonance wavelength corresponding to the optical distance is amplified and extracted. For this reason, it is said that sharp light with high luminance characteristics and a narrow spectrum width can be extracted.

  However, in the organic EL device adopting the optical resonator structure described above, when the spectrum width is narrowed, when the display surface is viewed obliquely, that is, as the viewing angle increases, the wavelength of light shifts to the lower wavelength side, There is a problem that the viewing angle dependency of the emission characteristics is high, such as a decrease in emission luminance. To solve this problem, for example, as disclosed in Patent Document 1, a configuration is disclosed in which the optical distance of light emitted from the light emitting layer is optimized to resonate so as to have a certain spectral width. .

International Publication No. 01/039554 Pamphlet

  In recent years, with the improvement in the quality of organic EL devices, further improvement in viewing angle characteristics has been demanded. FIG. 12 is a graph showing viewing angle characteristics of light emission luminance in a conventional organic EL device. In the figure, 0 degrees on the vertical axis in the upper half indicates the front of the viewer in the visual direction (normal direction of the display surface), that is, the viewing angle is 0 degrees. The light emission luminance is shown as a ratio when the light emission luminance at the position where the viewing angle is 0 degree is 100%, and is shown on a concentric circle with the center O being 0% and the outermost periphery being 100%.

  As shown in the figure, in the above prior art, the optical distance is optimized so that the emission luminance is maximized at the position where the viewing angle is 0 degree for each color of red light, green light, and blue light. When light is mixed, the optimum white light W is emitted at a viewing angle of 0 degree. As the viewing angle increases, the emission luminance of each color R, G, B decreases. That is, as the viewing angle increases, the optical distance deviates from the optimum condition and becomes longer, and the light to be extracted is not emitted under the optimum resonance wavelength condition.

  FIG. 13 is an xy chromaticity diagram showing the viewing angle characteristics of chromaticity in a conventional organic EL device. The solid line in the figure shows the change in the peak wavelength of the spectrum when the viewing angle changes from 0 degrees to 80 degrees. Show. As shown in the figure, in the above prior art, red light, green light, and blue light are emitted at an optimal chromaticity at a position where the viewing angle is 0 degrees (reference characters Ra, Ga, Ba in FIG. 13). The white light (reference numeral Wa in FIG. 13) is displayed.

  However, as shown in the above-mentioned patent document, as the viewing angle increases, when the peak wavelength of each color shifts from the optimum condition and shifts to the lower wavelength side (reference characters Rb, Gb, Bb in FIG. 13), overall There is a problem that color misregistration occurs. In other words, white light is displayed at a position where the viewing angle is 0 degree, but as the viewing angle increases, the light is shifted to the blue side (low wavelength side), and the display appears blue (reference numeral Wb in FIG. 13). .

  The present invention has been made in view of such circumstances, and an object thereof is to provide a light-emitting device and an electronic apparatus that can suppress color misregistration caused by a difference in viewing angle.

  As a result of various studies, the inventor has found that the configuration of the light emitting layer has a great influence on the color shift. Therefore, the inventor removes light in a wavelength region that causes color misregistration from emitted light in order to suitably suppress color misregistration even when the configuration of the light emitting layer is large and causes color misregistration. I thought of that.

  That is, in order to solve the above-described problem, a light-emitting device of the present invention includes a light-emitting layer sandwiched between a first electrode and a second electrode having transflective properties, and sandwiching the first electrode. An optical resonator configured to resonate emitted light, which is light emitted from the light emitting layer, between the light reflecting layer and the second electrode. A light emitting element having a structure, and a colored layer on which light emitted from the light emitting element is incident, facing the light emitting element, and the colored layer has a viewing angle of 0 degrees of the optical resonator structure. And transmitting light in a predetermined wavelength region including light having a resonance wavelength in FIG. 5 and absorbing light having a wavelength lower than the predetermined wavelength region.

  As described above, when the light emitting device having the optical resonator structure is observed from an oblique direction, the resonance wavelength shifts to the lower wavelength side, so that a wavelength shorter than the wavelength of the emitted light at the viewing angle of 0 degree becomes the resonance wavelength.

  At this time, for example, if the emitted light has a broad emission spectrum, light having a sufficient emission intensity may be emitted to the resonance wavelength when observed from an oblique direction. In such a case, the light in the wavelength region resonates, so that the light is amplified even when the resonance wavelength is shifted to the lower wavelength side. Therefore, the low wavelength shift of the emitted light is conspicuous, and color misregistration occurs.

  However, according to the configuration of the present invention, light that generates a color having a lower wavelength than the color of emitted light at a viewing angle of 0 degrees is absorbed by the colored layer. Therefore, in the light emitted after passing through the colored layer, light having a short wavelength that causes a low wavelength shift is reduced. Therefore, a light emitting device in which color misregistration is suppressed can be obtained.

In the present invention, the colored layer preferably has a transmittance of 10% or less in a wavelength region shorter by 30 nm or more from the peak wavelength where the transmittance is maximum to the low wavelength side.
According to this configuration, light having a lower wavelength than the predetermined wavelength region can be reliably removed from the light emitted through the colored layer, and color misregistration can be suppressed satisfactorily.

In the present invention, it is desirable to include a plurality of the light emitting elements having different resonance wavelengths at a viewing angle of 0 degrees and a plurality of the colored layers provided to face each of the plurality of light emitting elements.
According to this configuration, a light-emitting device capable of suppressing full-color display while suppressing color misregistration can be obtained.

An electronic apparatus according to the present invention includes the above-described light emitting device according to the present invention.
According to this configuration, since the light-emitting device described above is provided, a high-performance electronic device that suppresses color misregistration caused by a difference in viewing angle can be provided.

It is sectional drawing which showed schematic structure of the light-emitting device of this invention. It is explanatory drawing about the optical resonator structure which concerns on the light-emitting device of this invention. It is explanatory drawing shown about the light which concerns on the light-emitting device of this invention. It is a figure which shows the emission spectrum which concerns on the light emitting layer of the light-emitting device of this invention. It is explanatory drawing explaining the subject of this invention. It is explanatory drawing explaining the subject of this invention. It is explanatory drawing which shows the transmittance | permeability characteristic of the colored layer used for the light-emitting device of this invention. It is explanatory drawing explaining the effect of this invention. It is xy chromaticity diagram which shows the viewing angle characteristic of the light-emitting device of this invention. It is explanatory drawing explaining the other example of this invention. It is a perspective view which shows an example of the electronic device which concerns on this invention. It is xy chromaticity diagram which shows the viewing angle characteristic of the light-emitting luminance in the conventional light-emitting device. It is a chromaticity diagram which shows the viewing angle characteristic of chromaticity in the conventional light-emitting device.

  Hereinafter, a light emitting device according to an embodiment of the present invention will be described with reference to FIGS. In all the drawings below, the film thicknesses and dimensional ratios of the constituent elements are appropriately changed in order to make the drawings easy to see.

  In the description below, the light emitting device performs display using “red”, “green”, and “blue” light. The color of light here refers to the qualitative difference in “hue”, which indicates the difference in color appearance. In the present invention, the observer observes according to the actual usage of the light emitting device. Is a light that feels the hue.

  In the present invention, the wavelength of red light is 600 to 740 nm, the wavelength of green light is 520 to 565 nm, and the wavelength of blue light is 450 to 480 nm. However, the present invention is not limited to this.

  Here, first, an outline of an organic EL device (light emitting device) to which the present invention is applied will be described with reference to FIGS. 1 and 2, and due to the configuration of the light emitting element of the organic EL device with reference to FIGS. After describing the problem, the structure of the color filter included in the organic EL device of the present invention will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view showing a schematic configuration of an organic EL device exemplified as a light emitting device of the present invention.

  The organic EL device 1 of the present embodiment includes an organic functional layer 12 and a metal reflector (light reflecting layer) 15 sandwiched between an anode (first electrode) 10 and a cathode (second electrode) 11 on an element substrate 20A. A plurality of light emitting elements 21 having Further, the organic EL device 1 includes a pixel partition wall 13 that partitions the light emitting element 21 for each of the pixel regions XR, XG, and XB, and a sealing substrate 31 disposed to face the element substrate 20A.

  Since the organic EL device 1 employs a top emission type light emission method in which light is extracted from the sealing substrate 31 side, which is the opposite side of the element substrate 20A, the material of the element substrate 20A is either a transparent substrate or an opaque substrate. Can be used.

  As the transparent substrate, for example, an inorganic substance such as glass, quartz glass, or silicon nitride, or an organic polymer (resin) such as an acrylic resin or a polycarbonate resin can be used. In addition, a composite material formed by laminating or mixing the above materials can be used as long as it has optical transparency. Examples of opaque substrates include ceramics such as alumina, metal sheets such as stainless steel that have been subjected to insulation treatment such as surface oxidation, thermosetting resins and thermoplastic resins, and films thereof (plastic films). It is done.

    An inorganic insulating layer 14 made of silicon nitride or the like is formed on the element substrate 20A. On the inorganic insulating layer 14, a planarizing layer 16 is formed in which a metal reflector 15 made of an aluminum alloy or the like is housed. The planarizing layer 16 is formed using a heat-resistant insulating resin such as acrylic or polyimide to eliminate surface irregularities due to the thin film transistor (TFT) 123 or wiring.

    An anode 10 is formed on the planarization layer 16. The anode 10 is formed of a metal oxide-based transparent conductive material, and specifically, ITO (Indium Tin Oxide) is preferably used. The anode 10 is formed corresponding to each light emitting element 21, and one end thereof is connected to the TFT 123 through a contact hole 17 formed in the inorganic insulating layer 14.

  A pixel partition wall 13 is formed on the anode 10. The pixel partition 13 has an opening on the anode 10 and separates the plurality of light emitting elements 21 independently. A region surrounded by the pixel partition wall 13 is a pixel region of the light emitting element 21 and these are assigned as pixel regions XR, XG, and XB for extracting red light, blue light, and green light, respectively. ing. As a material for forming the pixel partition wall 13, for example, an insulating organic material such as polyimide or acrylic can be used. In addition, as a forming material of the pixel partition wall 13, a combination of an inorganic material and an organic material may be used.

  The organic functional layer 12 includes a hole injection / transport layer 30 and a light emitting layer 40. The hole injection / transport layer 30 is for injecting / transporting the holes of the anode 10 to the light emitting layer 40. The hole injection / transport layer 30 is formed across the pixel partition walls 13 on the anode 10 on the element substrate 20A.

  As a material for forming the hole injection / transport layer 30, an aqueous dispersion of 3,4-polyethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS) is particularly preferably used. The material for forming the hole injection / transport layer 30 is not limited to those described above, and various materials can be used. For example, a material obtained by dispersing polystyrene, polypyrrole, polyaniline, polyacetylene or a derivative thereof in an appropriate dispersion medium such as the aforementioned polystyrene sulfonic acid can be used.

  The light emitting layer 40 is a portion where light injected with a predetermined wavelength is emitted by combining electrons injected from the cathode 11 and holes injected from the hole injection / transport layer 30. The light emitting layer 40 is formed over the entire region on the hole injection / transport layer 30.

  The light emitting layer 40 employs a white light emitting layer that emits white light. As a method for causing the light-emitting layer 40 to emit white light, a method is adopted in which light-emitting layers that emit light of a plurality of colors are stacked to mix the color light emitted from each layer into pseudo white light. As the light emitting layer 40, the structure which mixes three colors, red, green, and blue, for example, and the structure which mixes two colors, blue and yellow, are employable.

  The light emitting layer 40 of this embodiment uses the light emitting layer 40 of the structure which laminated | stacked the red light emitting layer 40a, the green light emitting layer 40b, and the blue light emitting layer 40c, as shown in FIG.1 (b), Each colored layer 40a-40c. The three colors of light emitted from the light are mixed to emit white light.

  Examples of the constituent material of the light emitting layer 40 include a polyfluorene derivative (PF), a polyparaphenylene vinylene derivative (PPV), a polyparaphenylene derivative (PPP), polyvinyl carbazole (PVK), a polythiophene derivative, and polymethylphenylsilane (PMPS). Polymer organic materials such as polysilane derivatives such as can be used. In addition, the polymer organic material doped with a low molecular organic material such as perylene dye, coumarin dye, rhodamine dye, rubrene, 9,10-diphenylanthracene, tetraphenylbutadiene, nile red, quinacridone, etc. May be used. In addition, it is preferable to form an electron transport layer or a hole block layer on the light emitting layer 40.

  The cathode 11 has a transflective property of transmitting part of the light emitted from the light emitting layer 40 and reflecting part or all of the remaining light to the metal reflector 15 side. The cathode 11 is formed so as to cover the pixel partition wall 13 and the light emitting layer 40 on the element substrate 20A.

  The above-described light emitting layer 40 is sandwiched between the cathode 11 and the metal reflector 15, and optical resonance that resonates light emitted from the light emitting layer 40 between the cathode 11 and the metal reflector 15. A vessel structure is formed. The optical resonator structure will be described later.

  An organic buffer layer 18 is formed on the cathode 11. The organic buffer layer 18 is formed so as to fill the uneven portion of the cathode 11 formed in an uneven shape due to the influence of the shape of the pixel partition wall 13. The upper surface of the organic buffer layer 18 is formed to be substantially flat. The organic buffer layer 18 has a function of relieving stress generated by warpage and volume expansion of the element substrate 20A and preventing the cathode 11 from peeling from the pixel partition wall 13 having an unstable shape.

  A gas barrier layer 19 is formed on the organic buffer layer 18 so as to cover the organic buffer layer 18. The gas barrier layer 19 is for preventing oxygen and moisture from entering the inside thereof, thereby suppressing deterioration of the light emitting element 21 due to oxygen and moisture. In addition, since the upper surface of the organic buffer layer 18 described above is substantially planarized, the gas barrier layer 19 made of a hard film formed on the organic buffer layer 18 is also planarized. Therefore, there is no portion where stress is concentrated, and thereby, generation of cracks in the gas barrier layer 19 can be prevented. The material of the gas barrier layer 19 is preferably formed of a silicon compound containing nitrogen, that is, silicon nitride, silicon oxynitride, or the like in consideration of transparency, gas barrier properties, and water resistance.

  A seal layer 22 is formed on the gas barrier layer 19 so as to cover the gas barrier layer 19. The sealing layer 22 fixes the sealing substrate 31 on the gas barrier layer 19 and has a buffering function against mechanical shock from the outside, and protects the light emitting layer 40 and the gas barrier layer 19. The sealing layer 22 is formed of an adhesive made of a material that is softer than the sealing substrate 31 and has a low glass transition point, for example, a resin such as urethane, acrylic, epoxy, or polyolefin.

  The sealing substrate 31 is disposed to face the element substrate 20A described above. Since the upper surface of the sealing substrate 31 functions as a display surface for extracting light, the sealing substrate 31 is made of a light transmissive material such as glass or transparent plastic (polyethylene terephthalate, acrylic resin, polycarbonate, polyolefin, or the like).

  On the lower surface of the sealing substrate 31 (on the element substrate 20A side), a color filter 37 in which a red colored layer 37R, a green colored layer 37G, and a blue colored layer 37B are arranged in a matrix is configured. Each of the colored layers 37R, 37G, and 37B is a layer formed by mixing a pigment or a dye with a transparent binder layer. By selecting a pigment or other additive, the target red (R) or green (G) is selected. Or it is adjusted to blue (B).

  Each of the colored layers 37R, 37G, and 37B is disposed so as to face the anode 10 of the light emitting element 21, and among the light emitted from the light emitting layer 40, each color is selected according to the transmission characteristics of each colored layer to be described later. The light corresponding to the wavelength of the light passes through each of the colored layers 37 and is emitted to the viewer as light of each color.

  A black matrix layer 32 is formed between the regions of the colored layers 37R, 37G, and 37B. The black matrix layer 32 is configured as a non-light-emitting portion by dividing the colored layer 37, and prevents light leakage between adjacent pixel regions XR, XG, and XB. The constituent material of the black matrix layer 32 is a light shielding layer made of a resin mixed with a pigment such as carbon black. The black matrix layer 32 may be mixed with a liquid repellent resin such as a fluororesin.

  FIG. 2 is an explanatory diagram of an optical resonator structure included in the light emitting element 21 of the organic EL device 1, and is an enlarged view of a portion surrounded by a two-dot chain line in FIG.

  The resonance wavelength of each light emitting element 21 is the optical distance between the metal reflector 15 and the cathode 11, that is, each layer formed between the metal reflector 15 and the cathode 11 (for example, the organic functional layer 12 and the anode 10). ) Of each product of the film thickness and the refractive index.

  In the present embodiment, the optical distance is adjusted by controlling the film thickness of the anode 10, and the resonance wavelength of the light emitting element 21 is varied. Therefore, light of different colors is extracted from the light emitting element 21.

  The optical distance is L, the phase shift generated when the light emitted from the light emitting layer 40 is reflected by the anode 10 or the cathode 11 is Φ, and the peak wavelength of the spectrum of light to be extracted from the light emitted from the light emitting layer 40 is λ. Then, these relations can be expressed by the equation 2L = λ (m−Φ / 2π) (where m is an integer). The viewing angle described above is an angle formed between the visual direction and the normal line of the display surface of the sealing substrate 31.

  From the above equation, since the optical distance L is proportional to the desired light peak wavelength λ, the film thickness of the anode 10 is that of the light-emitting element 21 from which long-wavelength red light is extracted, and is green. The film thickness decreases in the order of the light emitting element from which the blue light is extracted and the light emitting element from which the blue light is extracted. This optical distance is usually set so that the color of the resonance wavelength when the display surface (the surface of the sealing substrate 31) is viewed from the front, that is, when the viewing angle is 0 degree, is an optimal color. .

  According to this configuration, the light emitted from the light emitting layer 40 reciprocates between the metal reflector 15 and the cathode 11, and only the light having the resonance wavelength corresponding to the optical distance is amplified and extracted. For this reason, light with high emission luminance and sharp spectrum can be extracted.

  With respect to the organic EL device having such a configuration, an operation of suppressing color misregistration will be described. In the following description, the light in each component of the organic EL device is expressed as shown in FIG. 3 in order to describe in more detail. FIG. 3 is an explanatory diagram of various types of light in the organic EL device 1 described above.

  First, the light L1 emitted from the light emitting layer 40 is referred to as “emitted light”. This is light having a wavelength corresponding to the composition of the light emitting layer 40, and is white light emitted in the present embodiment.

  Next, after the emitted light L1 resonates between the metal reflector 15 and the cathode 11 (optical resonator structure), the light L2 emitted from the light emitting element 21 is referred to as “emitted light”. This is light having a resonance wavelength of an optical resonator structure and exhibiting a predetermined color.

  Further, the light L3 extracted from the counter substrate 31 side after the emitted light L2 has passed through the colored layers 37R, 37G, and 37B is referred to as “visual light”. The visual light L3 is light that is emitted after the colored layer absorbs light having a part of the wavelength included in the emitted light L2, and is color light that is observed by an observer. When the color of the visible light L3 is shifted to the low wavelength side, a color shift that is a problem in the present invention occurs.

  Next, problems caused by the configuration of the light emitting layer will be described with reference to FIGS. As described above, since the organic EL device 1 employs a light emitting layer in which a plurality of light emitting layers are stacked to emit white light, the organic EL device 1 has specific problems as described below.

  FIG. 4 is a diagram showing an emission spectrum of the light emitting layer 40 that emits white light employed in the organic EL device of the present invention. In the drawing, as the configuration for emitting pseudo white light, the above-described configuration for mixing three colors is indicated as “3 peak”, and the configuration for mixing two colors is indicated as “2 peak”.

  As shown in the figure, white light emitted from the light emitting layer has a difference in emission intensity depending on the wavelength. The wavelength of the intensity peak (indicated by reference signs P1 to P3 in the spectrum of 3 peak and indicated by reference signs Pa and Pb in the spectrum of 2 peak) corresponds to the intensity peak of the light emitting material of each color constituting each light emitting layer.

  In addition, in the spectrum shown in the figure, the intensity peaks of the light emitting materials are clearly separated because the wavelengths indicating the intensity peaks of the light emitting materials are close to each other or because each light emitting material has a broad light emission characteristic. Not a continuous spectrum. Here, “continuous” indicates that the emission intensity does not decrease much even in the wavelength region between the intensity peaks.

  For example, in the spectrum of 3 peak, in the wavelength region between the intensity peak P1 attributed to the blue light emitting material and the intensity peak P2 attributed to the green light emitting material, the spectrums of both light emitting materials overlap to form a continuous spectrum. (Reference numeral X1). The same applies to the code X2 of the 2 peak spectrum.

  When emitted light having such an emission spectrum resonates in an optical resonator structure, the following problem occurs.

  FIG. 5 is an explanatory diagram for explaining the problem of the present invention, and is a diagram showing a spectrum of emitted light emitted from the light emitting element 21 having an optical resonator structure. In the figure, a case where the viewing angle for observing the organic EL device is 0 degree and a case where it is 60 degrees are shown together. In the organic EL device according to the present embodiment, red (R), green (G), and blue (B) light is emitted from different light emitting elements 21. Here, the behavior of the spectrum of each color is compared. In order to do this, the spectrum of each color is shown superimposed.

  When an organic EL device having a light emitting element having an optical resonator structure is observed from the front, the wavelength of the light of the color to be emitted by each light emitting element becomes the resonance wavelength, and the emitted light having the peak intensity at the wavelength of the color is emitted. Is done. This corresponds to the spectrum with a viewing angle of 0 degrees in the figure.

  On the other hand, when an organic EL device having a light emitting element having an optical resonator structure is observed from an oblique direction, the resonance wavelength of each light emitting element is shifted to the lower wavelength side. Therefore, the resonance wavelength peak position at a viewing angle of 60 degrees shown in the figure is shifted to a lower wavelength side than the resonance wavelength peak position at a viewing angle of 0 degrees in each color.

  In addition, the red and blue emission lights have a lower emission intensity in the spectrum after the low wavelength shift, whereas the green emission light does not change even before the shift even after the low wavelength shift. It is strong. As shown in FIG. 4, in the spectrum of the light emitting element of 3 peak, sufficient light emission intensity is obtained in the vicinity of the wavelength region indicated by the symbol X1 on the lower wavelength side than the position of the intensity peak P2 (corresponding to green). This is due to the light being emitted.

  That is, since the emitted light having a sufficient emission intensity is emitted also in the wavelength region, the light in the wavelength region resonates and is amplified to the same emission intensity as the emitted light before the shift. As a result, even when the resonance wavelength is shifted to the lower wavelength side, emitted light having the same emission intensity as that before the shift is emitted.

  In the case where a conventional color filter is provided facing the light emitting element exhibiting such behavior, the organic EL device develops color as shown in FIG. FIG. 6 is an xy chromaticity diagram showing the viewing angle characteristics of the organic EL device, and is a chromaticity diagram for the visible light L3 shown in FIG. The solid line in FIG. 6 shows the change in the peak wavelength of the spectrum observed when the viewing angle is changed from 0 degree to 60 degrees.

  In the figure, the chromaticity of each color at a viewing angle of 0 degrees is indicated by R1 for red light, G1 for green light, B1 for blue light, and white light W1. Light is indicated as R2, green light as G2, blue light as B2, and white light W2.

  As shown in the figure, when the conventional color filter is provided, the green visible light is changed with respect to the chromaticity change of the red visual light and the blue visual light (R1 → R2 and B1 → B2 in the figure). Since the chromaticity change (G1 → G2 in the figure) is large, it can be seen that the white visual light obtained by mixing each color light also causes a large color shift from white to blue side (W1 → W2 in the figure).

  Next, the structure which solves the problem resulting from the structure of the above-mentioned light emitting layer is demonstrated using FIGS. In the present invention, focusing on the light transmittance of the color filter facing the light emitting element, it is possible to solve the above-described problems and suppress the color shift of the visible light.

  FIG. 7 is a diagram showing the transmittance characteristics of each colored layer according to the color filter used in the organic EL device of the present invention. In the figure, the transmittance characteristics of the red (R), green (G), and blue (B) colored layers are shown at the same time for ease of explanation.

  As shown in the figure, the colored layer of the color filter used in the organic EL device of the present invention has a transmittance of 10% at a low wavelength side of 30 nm or more from the peak wavelength P (Pr, Pg, Pb) indicating the maximum transmittance. It is controlled to be as follows. Specifically, the red colored layer has a transmittance of 10% or less in a wavelength region of 570 nm or less. Similarly, the transmittance is 10% or less in the wavelength region of 490 nm or less for the green colored layer and in the wavelength region of 420 nm or less for the blue colored layer. The peak wavelength PW of each colored layer is approximately the same as the peak position of the resonance wavelength at a viewing angle of 0 degrees of the light emitting element, and is designed to favorably transmit light at the resonance wavelength at a viewing angle of 0 degrees.

  In the organic EL device of the present invention, a color filter having a colored layer having such transmittance characteristics is disposed opposite to the light emitting element. Therefore, the problem is solved by the action as shown in the following figure.

  FIG. 8 is an explanatory diagram for explaining the effect of the present invention that suppresses color misregistration in the organic EL device including the light emitting element having the spectrum of “3 peak” illustrated in FIG. 5.

  FIG. 8A is a diagram showing a spectrum of green emitted light emitted from the light emitting element when the organic EL device of the present invention is observed from a position with a viewing angle of 60 degrees, which is shown in FIG. Is the same. The green emission light is shifted by a low wavelength as described above.

  FIG. 8B is a diagram showing the transmittance characteristics of the green colored layer, which is the same as that shown in FIG. The green emission light shown in FIG. 8A is incident on the colored layer having such transmittance characteristics.

  FIG. 8C is a diagram showing a spectrum of green visible light that passes through the colored layer and is emitted from the pixel region. In the colored layer, light on the low wavelength side is absorbed from the green emission light having the emission spectrum described above. Therefore, the spectrum of the visible light has a wavelength near the peak wavelength corresponding to the transmission spectrum of the colored layer as shown in the figure (shaded portion in the figure).

  As described above, in the present invention, the color shift is prevented by absorbing the light on the low wavelength side with the colored layer and transmitting the light in the desired wavelength region. As shown in FIG. 5, in the case of a light emitting device having a spectrum of “3 peak”, the luminance of the green visual light is too strong compared to the red visual light and the blue visual light. The white visible light causes a large color shift. However, in the green visible light transmitted through the colored layer having the transmission characteristics as described above, the light of the wavelength on the low wavelength side is removed, and the luminance balance between red and blue visual recognition is good, and as a whole It becomes difficult to lose balance.

  FIG. 9 shows an xy chromaticity diagram showing the viewing angle characteristics of the organic EL device in which the colored layer of the color filter has the transmission characteristics as described above. FIG. 9 corresponds to FIG. In the figure, the chromaticity of each color at a viewing angle of 0 degrees is R3 for red light, G3 for green light, and B3 for blue light. As the viewing angle increases, R4 for red light, G4 for green light, and blue light. Is shown as shifting to the lower wavelength side toward B4.

  When FIG. 9 is compared with FIG. 6 (chromaticity diagram of an organic EL device having a conventional color filter), the change in chromaticity for red and blue visible light (R3 → R4 and B3 → B4 in the figure) is While there is no significant difference from the result shown in FIG. 6, the chromaticity change (G3 → G4 in the figure) of the green visible light is greatly reduced, and the white visual recognition obtained by mixing each color light It can be seen that the change in light is also a slight change amount (W3 → W4 in the figure). Therefore, it is confirmed from the chromaticity diagram that the overall color shift caused by the difference in viewing angle can be suppressed.

  According to the organic EL device 1 having the above-described configuration, it is possible to suppress color misregistration that occurs due to a difference in viewing angle and to perform high-quality display.

  In the present embodiment, the effect of green light has been described. However, in other color light (red light, blue light) emitted from the light emitting element, the light emission intensity sufficient for resonance at a wavelength lower than the resonance wavelength. Even when the emitted light is emitted, the problem can be solved by producing the same effect.

  FIG. 10 is a diagram illustrating a spectrum of light after resonance emitted from the light emitting element having the emission spectrum of “2 peak” illustrated in FIG. 4, and corresponds to FIG. 5. In this case, compared to the red, green, and blue light emission intensities when the viewing angle is 0 degree, red light and green light emit light with the same intensity as before the shift even after the low wavelength shift. Ejecting.

  The organic EL device having a light-emitting element having such an emission spectrum also has a colored layer that is controlled so that the transmittance on the wavelength side lower than the resonance wavelength by 30 nm or more is 10% or less as shown in FIG. By using a color filter, it is possible to efficiently remove light having a low wavelength that causes color misregistration and suppress color misregistration.

  In the present embodiment, the colored layer is provided so as to face all the light emitting elements 21. However, the colored layer may be provided only for the light emitting elements that emit light having a large color shift with respect to the viewing angle. . In a light-emitting element that is not provided with a colored layer, emitted light can be used as visible light, and absorption of unnecessary light in the colored layer can be suppressed. Therefore, light use efficiency can be increased and luminance reduction can be suppressed. it can.

  In the present embodiment, the organic EL device adopting the top emission type light emission method has been described. However, the organic EL device adopting the bottom emission type light emission method for extracting light from the element substrate 20A side. It is also possible to apply.

[Electronics]
Next, an embodiment of the electronic device of the present invention will be described. The electronic apparatus of the present invention has the organic EL device 1 described above as a display unit, and specifically, the one shown in FIG.

  FIG. 11A is a perspective view showing an example of a mobile phone. A mobile phone 1000 includes a display unit 1001 using the organic EL device 1 described above.

  FIG. 11B is a perspective view showing an example of a wristwatch type electronic device. A timepiece (electronic device) 1100 includes a display unit 1101 using the organic EL device 1 described above.

  FIG. 11C is a perspective view showing an example of a portable information processing apparatus such as a word processor or a personal computer. An information processing apparatus (electronic device) 1200 includes an input unit 1202 such as a keyboard, a display unit 1206 using the organic EL device 1 described above, and an information processing apparatus body (housing) 1204.

  FIG. 11D is a perspective view showing an example of a thin large-screen television. A thin large-screen TV (electronic device) 1300 includes a thin large-screen TV main body (housing) 1302, an audio output unit 1304 such as a speaker, and a display unit 1306 using the organic EL device 1 described above.

  Each of the electronic devices shown in FIGS. 11A to 11D includes the display units 1001, 1101, 1206, and 1306 having the organic EL device 1 described above, and thus occurs due to a difference in viewing angle in the display unit. It is intended to suppress the color shift.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Organic EL device (light emitting device), 10 ... Anode (first electrode), 11 ... Cathode (second electrode), 15 ... Metal reflector (light reflecting layer), 20A ... Element substrate (substrate), 21 ... Light emission Element, 37R ... Red colored layer (colored layer), 37G ... Green colored layer (colored layer), 37B ... Blue colored layer (colored layer), 40 ... Light emitting layer, 1000 ... Mobile phone (electronic device), 1100 ... Watch ( Electronic equipment), 1200 ... information processing device (electronic equipment), 1300 ... thin large television (electronic equipment), 1001, 1101, 1206, 1306 ... display unit (light emitting device), L1 ... emitted light, L2 ... emitted light

Claims (4)

A light emitting layer sandwiched between the first electrode and a second electrode having transflective properties; and a light reflecting layer disposed on the opposite side of the light emitting layer with the first electrode interposed therebetween. A light emitting element having an optical resonator structure configured to resonate light emitted from the light emitting layer between the light reflecting layer and the second electrode;
Opposite to the light emitting element, having a colored layer on which light emitted from the light emitting element is incident,
The colored layer transmits light in a predetermined wavelength range including light having a resonance wavelength at a viewing angle of 0 degree of the optical resonator structure, and absorbs light on a lower wavelength side than the predetermined wavelength range. A light emitting device characterized.   2. The light emitting device according to claim 1, wherein the colored layer has a transmittance of 10% or less in a wavelength region shorter by 30 nm or more from a peak wavelength at which the transmittance is maximum to a low wavelength side.   3. The light emitting device according to claim 1, further comprising: a plurality of the light emitting elements having different resonance wavelengths at a viewing angle of 0 degrees; and a plurality of the colored layers provided to face each of the plurality of light emitting elements. The light-emitting device of description.   An electronic apparatus comprising the light-emitting device according to claim 1.

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