JP2007043080A - Light source using organic light-emitting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source which has two or more linear organic light-emitting elements arrayed in parallel on a substrate and having a large long/short ratio, and is excellent in at least storing durability or rigidity. <P>SOLUTION: The light source is composed of the substrate, the two or more linear organic light-emitting elements arrayed in parallel on the substrate, and a sealing member covering the upper part of the light-emitting elements to seal them on the substrate. The long/short ratio of the organic light-emitting element is ≥200, the length of the sealing member along the organic light-emitting element is ≥200 mm, and the thickness of the same is ≥4 mm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light source (light emitting light source) using a linear organic electroluminescent element.

An organic electroluminescent element (hereinafter, referred to as “organic EL element” or “light emitting element” as appropriate) can emit light with high luminance at a low voltage. For example, a display element, a full color display, a backlight, illumination The use as various light sources, such as a light source, is seen as promising, and many developments are performed.
As one of organic EL element applications, a technique for making the light emitting element an elongated linear light source is disclosed (for example, see Patent Document 1).
An organic EL element is an element in which an organic compound layer made of an organic material is provided between electrodes. When moisture exists in the element, water is decomposed into oxygen and hydrogen by electrolysis, and the generated oxygen and hydrogen are There is a problem of deteriorating the durability of the element. For this reason, the method of sealing the produced element and shutting off oxygen and moisture in the air is employed. In particular, as a method for sealing the element, various sealing methods using various types of sealing members are considered (for example, see Patent Document 2).
JP 2003-51380 A JP 2004-9548 A

However, an organic EL element having a large length-to-short ratio (element length / width) may be distorted due to the size of the length-to-short ratio. In this case, in particular, when the element is used as a light source, the position of the light source becomes nonuniform and the sharpness of the image is impaired.
In addition, since a technology for reliably sealing an organic EL element having a long / short ratio (element length / width) has not yet been provided, there is a problem in the storage durability of the element.
The present invention has been made in view of the above circumstances, and is a light source having a linear organic electroluminescence device having a large length-to-short ratio arranged in parallel on a substrate, and has storage durability and rigidity. An object of the present invention is to provide a light source (light emitting light source) excellent in at least one of the above.

Means for solving the above-mentioned problems are as follows.
<1> A light source having a substrate, at least two linear organic electroluminescent elements arranged in parallel on the substrate, and a sealing member that covers the top of the light emitting element and seals the substrate. The length ratio of the organic electroluminescent element is 200 or more, the length of the sealing member along the longitudinal direction of the organic electroluminescent element is 200 mm or more, and the thickness is 4 mm or more. Light source.

<2> The light source according to <1>, wherein a difference in coefficient of linear thermal expansion between the substrate and the sealing member is less than 10 × 10 ⁻⁶ .
By setting the difference in coefficient of linear thermal expansion to less than 10 × 10 ⁻⁶ , it is possible to prevent distortion of the light source and exhibit rigidity.

<3> The light source according to <1> or <2>, wherein the sealing member is non-contact with the organic electroluminescent element and forms a hollow between the substrate and the substrate.
By forming a hollow between the substrate, a desiccant is installed between the sealing member and the substrate to further improve the storage durability of the device, or the sealing member and the organic electroluminescent device are in contact with each other Failures that occur can be avoided.

<4> The light source according to any one of <1> to <3>, further comprising a protective layer on the organic electroluminescent element.
By having a protective layer on the organic electroluminescent element, the storage durability of the organic EL element can be further improved and the impact resistance can be improved.

<5> The organic electroluminescent element has a plurality of light emitting units each including a light emitting layer between an anode and a cathode, and has a charge generation layer between the plurality of light emitting units <1 The light source according to any one of> to <4>.
The organic electroluminescent element has a plurality of light emitting units each including a light emitting layer between an anode and a cathode, and has a charge generation layer between the plurality of light emitting units, thereby further improving the luminous efficiency of the organic EL element. Can be improved.

<6> The organic electroluminescent element has a plurality of light emitting units each including a light emitting layer between an anode and a cathode, and has a conductive layer between the plurality of light emitting units <1 The light source according to any one of> to <4>.
The organic electroluminescent element has a plurality of light emitting units each including a light emitting layer between an anode and a cathode, and has a conductive layer between the plurality of light emitting units, thereby further improving the luminous efficiency of the organic EL element. Can be improved.

  According to the present invention, a light source having a linear organic electroluminescence device having a large length-to-short ratio arrayed in parallel on a substrate and having excellent storage durability and rigidity is provided. Light source).

Hereinafter, the present invention will be described in detail.
A light source of the present invention includes a substrate, at least two linear organic electroluminescent elements arranged in parallel on the substrate, and a sealing member that covers the upper portion of the light emitting element and seals the substrate. It is a light source, The length ratio of the organic electroluminescent element is 200 or more, the length of the sealing member along the longitudinal direction of the organic electroluminescent element is 200 mm or more, and the thickness is 4 mm or more. It is characterized by that.

In the present invention, it is necessary that the length of the sealing member along the longitudinal direction of the organic EL element is 200 mm or more and the thickness is 4 mm or more.
The thickness of the sealing member is preferably 4 to 20 mm, and more preferably 4 to 10 mm.
The length along the longitudinal direction of the organic EL element of the sealing member is 200 mm or more, and is set so as to cover the entire element according to the number of organic EL elements arranged.

  By forming the sealing member with a length along the longitudinal direction of the organic EL element of 200 mm or more and a thickness of 4 mm or more, a portion (pixel portion) formed by two or more linear organic EL elements The element can be reliably sealed to prevent entry of moisture, oxygen, and the like from the outside, so that the storage durability of the element is improved. In addition, since the entire structure of the light source exhibits rigidity, it is not distorted, and even when the width of the pixel portion is narrow (for example, when the pixel portion is formed in a rectangular shape), moisture / oxygen from the outside Etc. can be prevented.

From the viewpoint of preventing distortion of the light source and exhibiting rigidity, the difference in coefficient of linear thermal expansion between the substrate and the sealing member is preferably less than 10 × 10 ^{−6, and} less than 7 × 10 ^−6. More preferred is less than 3 × 10 ⁻⁶ . The measurement temperature of the linear thermal expansion coefficient is not particularly limited, but is preferably within the operating temperature range of the light source, preferably −20 ° C. or more and 100 ° C. or less, more preferably 0 ° C. or more and 100 ° C. or less, and 20 ° C. or more and 100 ° C. The following is more preferable, 20 ° C. or higher and 80 ° C. or lower is particularly preferable, and 20 ° C. is most preferable. Here, the linear thermal expansion coefficient can be measured based on a known measurement method, but is measured according to a method described in JIS or the like depending on the material. For example, the measuring method described in JIS R3102 (1995) for glass materials, JIS Z2285 (2003) for metal materials, and JIS K7197 (1991) for plastic materials can be suitably applied.

The material of the sealing member is not particularly limited as long as the above linear thermal expansion coefficient condition is satisfied. Inorganic material such as soda glass and non-alkali glass, metal material such as stainless steel and aluminum alloy, polyethylene terephthalate, polybutylene Polyester such as terephthalate and polyethylene naphthalate, polyethylene, polycarbonate, polyethersulfone, polyarylate, allyl diglycol carbonate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), Teflon (registered trademark), poly Examples thereof include a high molecular weight material such as a tetrafluoroethylene-polyethylene copolymer, which can be appropriately selected and used in combination with a substrate.
The sealing member is a member that covers the upper part of the organic EL element and seals it on the substrate. In addition to the reverse concave shape, the sealing member has, for example, a substrate side of the sealing member in order to improve the second moment of section and to increase the rigidity. It is also possible to provide ribs or irregularities on the surface or the opposite surface.

  The material of the substrate is not particularly limited, but inorganic materials such as zirconia-stabilized yttrium and glass, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene, polycarbonate, polyethersulfone, polyarylate, and allyl diene. Examples include high molecular weight materials such as glycol carbonate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), Teflon (registered trademark), and polytetrafluoroethylene-polyethylene copolymer.

The range of the long / short ratio (aspect ratio) of the organic EL element in the present invention needs to be 200 or more, and the upper limit is not particularly limited, but is preferably 16000 or less. The range of the aspect ratio is preferably 300 or more and 16000 or less, more preferably 500 or more and 16000 or less, and further preferably 1000 or more and 10,000 or less. Especially preferably, it is 2000 or more and 10,000 or less, Most preferably, it is 5000 or more and 10,000 or less.
Here, the length-to-short ratio is a value obtained by dividing the length in the longitudinal direction of the organic EL element by the length in the direction perpendicular to the longitudinal direction.
The length in the longitudinal direction of the organic EL element can be appropriately set according to the application mode of the element, but is preferably 100 to 2000 mm from the viewpoint of providing a large area planar light source and its ease of manufacture. 1000 mm is more preferable.

  The light source of the present invention has at least two linear organic EL elements having a long and short ratio arranged in parallel on a substrate. From the viewpoint of providing a large area planar light source, it is preferable to arrange 100 or more of the linear organic EL elements in parallel, and more preferably 200 or more in parallel. The width of the linear organic EL element is preferably 5 μm or more and 1 mm or less, more preferably 10 μm or more and 500 μm or less, and particularly preferably 10 μm or more and 100 μm or less from the viewpoint of image sharpness. The interval between the linear organic EL elements is preferably 5 μm or more and 1 mm or less, more preferably 10 μm or more and 500 μm or less, and particularly preferably 10 μm or more and 100 μm or less from the viewpoint of image sharpness.

  As in the present invention, the method of configuring a planar light source by arranging a large number of linear light sources in parallel is compared with a method of configuring a planar light source by installing point light sources in a matrix in the XY direction. Thus, a planar light source can be formed more easily, and a circuit for driving the light source, a power source, and the like can be made simple. Furthermore, in the light source of the present invention, the luminance gradation can be controlled by controlling the lighting line frequency of the linear organic EL element, and the linear organic EL element is caused to emit light sequentially according to time. And you can get a visual effect.

The organic EL device of the present invention is configured such that the organic compound layer includes at least one organic compound layer including an organic light emitting layer (hereinafter sometimes simply referred to as “light emitting layer”) between a pair of electrodes. In addition to the light emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and the like may be included.
One preferable aspect of the organic EL element in the present invention is an aspect in which a plurality of light emitting units each including a light emitting layer are provided between an anode and a cathode, and a charge generation layer is provided between the plurality of light emitting units. Another preferred embodiment is an embodiment in which a plurality of light emitting units each including a light emitting layer are provided between an anode and a cathode, and a conductive layer is provided between the plurality of light emitting units.

The organic EL element, for example, forms an electrode on a substrate, forms an insulating layer thereon, and then removes the insulating layer corresponding to the formation portion of the organic EL element by etching or the like, and further, an organic compound layer, and The electrodes can be provided by sequentially forming them.
A protective layer may be further provided on the organic EL element.
In addition, each element (specific aspects, such as an electrode, an organic compound layer, a protective layer) which comprises an organic EL element is explained in full detail later.

For sealing, after forming an organic EL element on the substrate, a sealing agent is applied to the outer peripheral portion of the sealing member and / or the substrate, and the sealing member is placed thereon, and the substrate and the sealing member Can be performed by adhering.
As the sealant, a known adhesive used for sealing an organic EL element, such as an ultraviolet curable resin, a photocurable resin, or a thermosetting resin, can be used.

In the present invention, it is preferable that the sealing member is non-contact with the organic electroluminescent element and forms a hollow between the sealing member and the substrate.
The hollow portion may be filled with a moisture absorbent (drying agent) or an inert liquid. The moisture absorbent is not particularly limited, but for example, barium oxide, sodium oxide, potassium oxide, calcium oxide, sodium sulfate, calcium sulfate, magnesium sulfate, phosphorus pentoxide, calcium chloride, magnesium chloride, copper chloride, Examples thereof include cesium fluoride, niobium fluoride, calcium bromide, vanadium bromide, molecular sieve, zeolite, and magnesium oxide. The inert liquid is not particularly limited, and examples thereof include paraffins, liquid paraffins, fluorinated solvents such as perfluoroalkane, perfluoroamine, and perfluoroether, chlorinated solvents, and silicone oils. .

  Further, the hollow may be divided by a member that abuts the sealing member and the substrate and divides the hollow.

1A and 1B are diagrams showing an embodiment of a light source of the present invention. FIG. 1A is a top view, and FIG. 1B is a cross-sectional view taken along line AA in FIG. It is.
In FIG. 1A, the light source 10 includes a substrate 12, an organic EL element 14 arranged in parallel on the substrate 12, and a sealing member 20.
The organic EL elements 14 are arranged in parallel to the Y direction so that the longitudinal direction thereof is along the end of the substrate 12 in the X direction.
As shown in FIG. 1B, the organic EL element 14 includes an organic compound layer 14B between an electrode 14A provided on the substrate 12 and an electrode 14C that is a counter electrode.
The sealing member 20 is a reverse concave sealing member that covers the entire organic EL elements 14 arranged in parallel and seals the substrate 20.
In this embodiment, the substrate 30 and the sealing member 20 constitute a hollow 30.

<Organic EL device>
Hereinafter, the organic EL element in the present invention will be described.
As described above, the organic EL element in the present invention is a linear element having a length ratio of 200 or more, and is arranged in parallel on at least two or more on the substrate.
The organic EL element in the present invention has a cathode and an anode on a substrate, and has at least one organic compound layer including a light emitting layer between both electrodes. In view of the properties of the light emitting element, at least one of the anode and the cathode is preferably transparent.

  As an aspect of lamination of the organic compound layer in the present invention, an aspect in which a hole transport layer, a light emitting layer, and an electron transport layer are laminated in this order from the anode side is preferable. Further, a charge blocking layer or the like may be provided between the hole transport layer and the light-emitting layer, or between the light-emitting layer and the electron transport layer. A hole injection layer may be provided between the anode and the hole transport layer, and an electron injection layer may be provided between the cathode and the electron transport layer. The light emitting layer may be only one layer, or the light emitting layer may be divided into a first light emitting layer, a second light emitting layer, a third light emitting layer, and the like. Furthermore, each layer may be divided into a plurality of secondary layers.

-Light emitting layer-
The light-emitting layer receives holes from the anode, the hole injection layer, or the hole transport layer when an electric field is applied, receives electrons from the cathode, the electron injection layer, or the electron transport layer, and recombines holes and electrons. It is a layer which has the function to provide and to emit light.
The light emitting layer in the present invention may be composed only of a light emitting material, or may be a mixed layer of a host material and a light emitting material. The light emitting material may be a fluorescent light emitting material or a phosphorescent light emitting material. The light emitting material may be one type or two or more types.
The host material is preferably a charge transport material. The host material may be one kind or two or more kinds, and examples thereof include a configuration in which an electron transporting host material and a hole transporting host material are mixed. Furthermore, the light emitting layer may include a material that does not have charge transporting properties and does not emit light.
Further, the light emitting layer may be a single layer or two or more layers, and each layer may emit light in different emission colors.

  There is no restriction | limiting in particular as an example of the fluorescent luminescent material which can be used for this invention, It can select suitably from well-known things. Examples include those described in paragraph No. [0027] of JP-A No. 2004-146067 and paragraph No. [0057] of JP-A No. 2004-103577, but the present invention is not limited thereto.

  The phosphorescent material that can be used in the present invention is not particularly limited and can be appropriately selected from known materials. Examples include those described in paragraph numbers [0051] to [0057] of JP-A-2004-221068, but the present invention is not limited thereto.

The organic EL device of the present invention has a configuration in which a plurality of light emitting units each including a light emitting layer are provided between an anode and a cathode, and a charge generation layer is provided between the plurality of light emitting units, in order to improve light emission efficiency. Can take.
The charge generation layer is a layer having a function of generating charges (holes and electrons) when an electric field is applied and a function of injecting the generated charges into a layer adjacent to the charge generation layer.
The charge generation layer is also preferably configured as a conductive layer.

The material for forming the charge generation layer may be any material having the above-described function, and may be formed of a single compound or a plurality of compounds.
Specifically, it may be a conductive material, a semiconductive material such as a doped organic layer, or an electrically insulating material. 11-329748, JP2003-272860A, and JP2004-39617A.
More specifically, ITO, IZO (indium zinc oxide) transparent conductive material, fullerenes such as C _60, such as, conductive organic materials such as oligothiophene, metal phthalocyanines, metal free phthalocyanines, metal porphyrins, no Conductive organic materials such as metal porphyrins, metal materials such as Ca, Ag, Al, Mg: Ag alloy, Al: Li alloy, Mg: Li alloy, hole conductive materials, electron conductive materials, and mixtures thereof You may use what was made to do.
The hole-conducting material is, for example, a material obtained by doping a hole-transporting organic material such as 2-TNATA or NPD with an electron-withdrawing oxidizing agent such as F4-TCNQ, TCNQ, or FeCl3, or P-type conductivity. Examples of such materials include polymers and P-type semiconductors. Electron-conducting materials include electron-transporting organic materials doped with metals or metal compounds having a work function of less than 4.0 eV, N-type conductive polymers, and N-type semiconductors. Is mentioned. Examples of the N-type semiconductor include N-type Si, N-type CdS, and N-type ZnS. Examples of the P-type semiconductor include P-type Si, P-type CdTe, and P-type CuO.
An electric insulating material such as V ₂ O ₅ can also be used for the charge generation layer.

  The charge generation layer may be a single layer or a stack of a plurality of layers. A structure in which a plurality of layers are stacked includes a conductive material such as a transparent conductive material and a metal material and a hole conductive material, or a structure in which an electron conductive material is stacked, and the above hole conductive material and electron conductive And a layer having a structure in which a functional material is laminated.

In general, it is preferable to select a film thickness and a material for the charge generation layer so that the visible light transmittance is 50% or more. The film thickness is not particularly limited, but is preferably 0.5 to 200 nm, more preferably 1 to 100 nm, still more preferably 3 to 50 nm, and particularly preferably 5 to 30 nm.
The method for forming the charge generation layer is not particularly limited, and the above-described method for forming the organic compound layer can be used.

The charge generation layer is formed between a plurality of light emitting units. The anode side and the cathode side of the charge generation layer may include a material having a function of injecting charges into adjacent layers. In order to improve the electron injection property to the layer adjacent to the anode side, for example, an electron injection compound such as BaO, SrO, Li ₂ O, LiCl, LiF, MgF ₂ , MgO, and CaF _{2 is} added to the anode side of the charge generation layer. May be laminated.
In addition to the contents mentioned above, the material for the charge generation layer should be selected based on the descriptions in JP-A-2003-45676, US Pat. Nos. 6,337,492, 6,107,734, 6,872,472, and the like. Can do.

  As an organic EL element in the present invention, FIG. 2 shows a configuration example of an organic EL element when a layer configuration having a charge generation layer between a plurality of light emitting units is applied. Further, FIG. 3 shows a configuration example of an organic EL element when a layer configuration having a conductive layer between a plurality of light emitting units is applied as the organic EL element. The present invention is not limited to this.

In FIG. 2, 40 shows the organic EL element in the light source of this invention. The organic EL element 40 includes light emitting units 46A, 46B, 46C, and 46D including a light emitting layer between an anode 44 and a cathode 50 provided on a substrate 42, and a charge generation layer 48A between each of the light emitting units. , 48B, and 48C. The anode 44 and the cathode 50 are connected via a power source 52.
The light emitting units 46A, 46B, 46C, and 46D including the light emitting layer may have the same layer configuration or may be different. The charge generation layers 48A, 48B, and 48C may have the same layer configuration or may be different.

In FIG. 3, reference numeral 60 denotes an organic EL element in the light source of the present invention. The organic EL element 60 includes a light emitting unit 66A, 66B, 66C, and 66D including a light emitting layer between an anode 64 and a cathode 70 provided on a substrate 62, and a conductive layer 68A between each of the light emitting units. 68B and 68C. The anode 64 and the cathode 70 are connected via a power source 72.
The light emitting units 66A, 66B, 66C, and 66D including the light emitting layer may have the same layer configuration or may be different. The conductive layers 68A, 68B, and 68C may have the same layer configuration or may be different.

  Regarding other components such as a substrate, an electrode, each organic layer, and other layers in the organic EL element, for example, paragraphs [0013] to [0082] of JP-A-2004-221068, JP-A-2004-2004 No. 214178 [0017] to [0091], JP 2004-146067 A [0024] to [0035], JP 2004-103577 A [0017] to [0068], JP 2003-323987 A [0014] to [0062] of JP-A-2002-305083, [0015] to [0077] of JP-A-2002-305083, [0008] to [0028] of JP-A-2001-172284, and JP-A-2000-186094. [0013] to [0075], [0016] to [0] of JP-T-2003-515897 18] as described in the like, it can be similarly applied to the present invention. However, the present invention is not limited to these.

  Regarding the driving method of the organic EL element in the present invention, each of JP-A-2-148687, JP-A-6-301355, JP-A-5-290080, JP-A-7-134558, JP-A-8-234658, and JP-A-8-2441047. The driving methods described in the publications, Japanese Patent No. 2784615, US Pat. Nos. 5,828,429 and 6023308, and the like can be applied.

The organic EL element in the present invention preferably has a protective layer on the element in order to prevent moisture and oxygen from entering. As a material contained in the protective layer, any material may be used as long as it has a function of preventing materials that promote device deterioration such as moisture and oxygen from entering the device. Specific examples thereof include metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, and Ni, MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, CaO, BaO, and Fe ₂ O. ₃ , metal oxides such as Y ₂ O ₃ and TiO ₂ , metal fluorides such as MgF ₂ , LiF, AlF ₃ , and CaF ₂ , SiN _x , SiO _x N _y Such as nitride, polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, tetrafluoroethylene And a copolymer obtained by copolymerizing a monomer mixture containing at least one comonomer, a fluorine-containing copolymer having a cyclic structure in the copolymer main chain, a water-absorbing substance having a water absorption of 1% or more, a water absorption of 0 .1% or less of moisture-proof substances and the like.
There is also no particular limitation on the method for forming the protective layer. For example, vacuum deposition, sputtering, reactive sputtering, MBE (molecular beam epitaxy), cluster ion beam, ion plating, plasma polymerization (high frequency excitation) (Ion plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, printing method, transfer method can be applied.

  The use of the light source of the present invention is not particularly limited. For example, when used as a reading light source, it is possible to read an image (electronic latent image) with high definition without requiring a scanning machine mechanism. In addition, line pixels are lighted sequentially as a sine light source, and the light effect is improved by random lighting, and because of the high-definition, high-intensity light source, brightness gradation control is possible with the lighting line frequency, and current / voltage control For example, a power supply circuit that does not need to be used can be used.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Example 1]
On an 465 × 440 × 0.7 mm ITO substrate (soda glass, coefficient of linear thermal expansion: 9 × 10 ⁻⁶ ), a pixel 430 mm × 50 μm (length ratio: 8600) is formed by an organic EL element having the following configuration (A). Pixel portions (430 × 430 mm) separated by partition walls were provided so that the pixels had a pitch of 100 μm. Organic of sealing member (soda glass, linear thermal expansion coefficient: 9 × 10 ⁻⁶ , 433 mm × 433 mm × 5 mm, glass digging depth on the inner organic EL element side: 1 mm, paste margin on outer periphery: 1 mm width) After putting the desiccant HD-S (made by Dynic) in the center of the EL element side, the sealant XNR5516-HV-B1 (manufactured by Nagase Sangyo Co., Ltd.) is applied to the glue part on the outer periphery, and the pixel part is The substrate was placed so as to be covered, and cured and sealed at 6 J / cm ² (365 nm) using a mercury lamp 400W while applying pressure so that the gap between the substrate and the sealing member was 12 μm.
The light source of Example 1 was produced as described above.

<Configuration (A)>
Anode: ITO (substrate)
Hole injection layer: CuPc (copper phthalocyanine) [10 nm]
Hole transport layer: NPD [30 nm]
Light emitting layer: mixed layer of mCP (95%) and Ferric (5%) [30 nm]
Hole blocking layer: Balq ₂ [10 nm]
Electron transport layer: Alq ₃ [40 nm]
Electron injection layer: LiF [0.5 nm]
Cathode: Al [100 nm]

The structures of CuPc, NPD, mCP, Firepic, Balq ₂ , and Alq ₃ are shown below.

[Example 2]
On the ITO substrate of 275 × 310 × 0.7 mm (soda glass, coefficient of linear thermal expansion: 9 × 10 ⁻⁶ ), the organic EL element having the above-described configuration A is used to provide a pixel 240 mm × 25 μm (long / short ratio: 9600), between the pixels The pixel portions (240 × 300 mm) separated by the partition walls were provided so that the pitch was 50 μm. Organic of sealing member (soda glass, linear thermal expansion coefficient: 9 × 10 ⁻⁶ , 243 mm × 303 mm × 5 mm, glass digging depth on the inner organic EL element side: 1 mm, paste margin on outer periphery: 1 mm width) After the desiccant HD-S (made by Dynic) is put in the center part on the EL element side, the sealant XNR5516-HV-B1 (manufactured by Nagase Sangyo Co., Ltd.) is applied to the paste margin part on the outer periphery so as to cover the pixel part. The substrate was placed and cured and sealed at 6 J / cm ² (365 nm) using a mercury lamp 400W while applying pressure so that the gap between the substrate and the sealing member was 12 μm.
The light source of Example 2 was produced as described above.

[Example 3]
The light source of Example 3 was produced in the same manner as in Example 1 except that the ITO substrate was changed to (non-alkali glass, linear thermal expansion coefficient: 3 × 10 ⁻⁶ ) instead of the ITO substrate of Example 1.

[Example 4]
The light source of Example 4 was produced in the same manner as in Example 1 except that the sealing member (SUS430, linear thermal expansion coefficient: 11 × 10 ⁻⁶ ) was used instead of the sealing member of Example 1.

[Comparative Example 1]
In place of the sealing member of Example 1, the sealing member (soda glass, linear thermal expansion coefficient: 9 × 10 ⁻⁶ , 433 mm × 433 mm × 1.1 mm, glass digging depth on the inner organic EL element side: A light source of Comparative Example 1 was produced in the same manner as in Example 1 except that 0.5 mm and the outer margin of the outer periphery: 1 mm width) were used.

[Comparative Example 2]
A light source of Comparative Example 2 was produced in the same manner as in Example 1 except that the sealing member (aluminum, linear thermal expansion coefficient: 25 × 10 ⁻⁶ ) was used instead of the sealing member of Example 1.

The following evaluation was performed using each obtained light source. The results are shown in Table 1.
<Gap between the center and end of the light source>
The substrate side of each light source is placed in contact with the upper surface of a surface plate (surface plate temperature of 20 ° C.) having a flatness of 2 μm or less, and then a gap (bending between the center portion and the end portion of each light source by a laser micro gauge. ) Was measured. Here, the flatness refers to the height of the undulation of the surface in a predetermined range of the surface plate.

  As shown in Table 1, it was confirmed that the light sources of the examples were excellent in image sharpness and storage durability because there was no distortion.

  In addition, as an organic EL element in the light source of Examples 1 to 4, a plurality of layer configurations A are provided as light emitting units, and a charge generation layer or a conductive layer is formed between the plurality of light emitting units, for example, FIG. An organic EL element having the configuration shown in FIG. 3 can also be applied.

(A) is a top view of one Embodiment of this invention, (b) is sectional drawing along the AA of (a). It is a schematic block diagram which shows an example of the organic EL element which has a charge generation layer between several light emission units which can be applied to the light source of this invention. It is a schematic block diagram which shows an example of the organic EL element which has a conductive layer between the several light emission units which can be applied to the light source of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light source 12 Board | substrate 14 Organic electroluminescent element 14a Electrode 14b Organic compound layer 14c Electrode 20 Sealing member 30 Hollow 40 Organic electroluminescent element 42 Substrate 44 Anode 46A, 46B, 46C, 46D Light emitting unit 48A, 48B, 48C containing a light emitting layer Charge generation layer 50 Cathode 52 Power supply 60 Organic electroluminescent device 62 Substrate 64 Anode 66A, 66B, 66C, 66D Light emitting unit including light emitting layer 68A, 68B, 68C Conductive layer 70 Cathode 72 Power supply

Claims (6)

A light source comprising: a substrate; at least two linear organic electroluminescent elements arranged in parallel on the substrate; and a sealing member that covers the top of the light emitting element and seals the substrate.
The organic electroluminescent element has a length-to-short ratio of 200 or more, and the sealing member has a length along the longitudinal direction of the organic electroluminescent element of 200 mm or more and a thickness of 4 mm or more. . The light source according to claim 1, wherein a difference in coefficient of linear thermal expansion between the substrate and the sealing member is less than 10 × 10 ⁻⁶ .   3. The light source according to claim 1, wherein the sealing member is not in contact with the organic electroluminescent element and forms a hollow between the substrate and the substrate.   The light source according to claim 1, further comprising a protective layer on the organic electroluminescent element.   The organic electroluminescent device has a plurality of light emitting units each including a light emitting layer between an anode and a cathode, and has a charge generation layer between the plurality of light emitting units. Item 5. The light source according to any one of Items 4.   The organic electroluminescent element has a plurality of light emitting units each including a light emitting layer between an anode and a cathode, and has a conductive layer between the plurality of light emitting units. Item 5. The light source according to any one of Items 4.

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