JPH10255978A - Luminescent display panel - Google Patents
Luminescent display panelInfo
- Publication number
- JPH10255978A JPH10255978A JP9076532A JP7653297A JPH10255978A JP H10255978 A JPH10255978 A JP H10255978A JP 9076532 A JP9076532 A JP 9076532A JP 7653297 A JP7653297 A JP 7653297A JP H10255978 A JPH10255978 A JP H10255978A
- Authority
- JP
- Japan
- Prior art keywords
- light
- glass substrate
- layer
- multilayer film
- organic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000011521 glass Substances 0.000 claims abstract description 60
- 239000002184 metal Substances 0.000 claims abstract description 24
- 229910052751 metal Inorganic materials 0.000 claims abstract description 24
- 230000005525 hole transport Effects 0.000 claims abstract description 9
- 239000000758 substrate Substances 0.000 claims description 55
- 230000002452 interceptive effect Effects 0.000 claims description 2
- 239000010408 film Substances 0.000 abstract description 55
- 238000004519 manufacturing process Methods 0.000 abstract description 8
- 239000010409 thin film Substances 0.000 abstract description 7
- 238000007738 vacuum evaporation Methods 0.000 abstract description 3
- 229910052737 gold Inorganic materials 0.000 abstract description 2
- 238000010030 laminating Methods 0.000 abstract 1
- 230000003287 optical effect Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 238000004088 simulation Methods 0.000 description 6
- 230000010287 polarization Effects 0.000 description 5
- 238000002834 transmittance Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 230000002411 adverse Effects 0.000 description 2
- 238000005401 electroluminescence Methods 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 229910017888 Cu—P Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000001579 optical reflectometry Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
Classifications
-
- H01L51/5281—
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、有機ＥＬ素子等、
透明のガラス基板に発光層を含む複数の層を積層して構
成する自発光素子を用いた発光ディスプレイパネルに関
する。[0001] The present invention relates to an organic EL device and the like.
The present invention relates to a light-emitting display panel using a self-luminous element formed by stacking a plurality of layers including a light-emitting layer on a transparent glass substrate.
【０００２】[0002]
【従来の技術】従来、文字や映像の表示装置のディスプ
レイパネルに用いられている自発光素子として有機ＥＬ
（ｅｌｅｃｔｒｏｌｕｍｉｎｅｓｃｅｎｃｅ）素子が知
られている。図４は従来の有機エレクトロルミネセンス
素子（以下有機ＥＬ素子という）の概略断面図である。
有機ＥＬ素子は、透明なガラス基板１０１の一方の面上
に透明な陽極１０２が形成され、さらに陽極１０２上に
は有機発光層や有機正孔輸送層等から成る発光層１０３
が形成されて、さらにその上にはＡｌ等の金属からなる
陰極１０４が真空蒸着等によって形成されている。2. Description of the Related Art Conventionally, an organic EL is used as a self-luminous element used for a display panel of a character or video display device.
(Electroluminescence) elements are known. FIG. 4 is a schematic sectional view of a conventional organic electroluminescence device (hereinafter referred to as an organic EL device).
In the organic EL device, a transparent anode 102 is formed on one surface of a transparent glass substrate 101, and a light emitting layer 103 including an organic light emitting layer and an organic hole transport layer is formed on the anode 102.
Is formed thereon, and a cathode 104 made of a metal such as Al is formed thereon by vacuum evaporation or the like.
【０００３】また陰極１０４は所定の形状にパターニン
グされていて、陰極１０４と陽極１０２間に接続された
駆動源１０５から供給される電圧によって両極間に位置
する発光層１０３に電流が流れ、陰極１０４及び陽極１
０２のパターン形状に応じて発光光を出射し、透明なガ
ラス基板１０１を介して外部に放射することにより、陽
極１０２のパターン形状が発光表示される。従来の有機
ＥＬ素子はこのように構成され、表示画素やユニットと
して文字や映像の表示装置のディスプレイパネルに用い
られる。The cathode 104 is patterned into a predetermined shape, and a current supplied to a light-emitting layer 103 located between both electrodes by a voltage supplied from a driving source 105 connected between the cathode 104 and the anode 102, And anode 1
By emitting light in accordance with the pattern shape of No. 02 and radiating the light to the outside through the transparent glass substrate 101, the pattern shape of the anode 102 is illuminated and displayed. The conventional organic EL element is configured as described above, and is used as a display pixel or unit in a display panel of a character or video display device.
【０００４】この種のディスプレイパネルにおいては、
ガラス基板１０１を通じて入射する外部光が陰極１０４
で反射する結果、表示面における発光光の表示コントラ
ストが低下するという問題が有る。その対策として、従
来、ガラス基板１０１の外部側の面上に反射防止フィル
タを設けることが行われている。In this type of display panel,
External light incident through the glass substrate 101 is
As a result, there is a problem that the display contrast of the emitted light on the display surface is reduced. As a countermeasure, an antireflection filter is conventionally provided on the outer surface of the glass substrate 101.
【０００５】図５は、反射防止フィルタを設けた有機Ｅ
Ｌ素子の一例を示した主要部構成図であり、（ａ）は主
要部断面図を示し、（ｂ）は（ａ）の一部拡大図を示し
ている。図５（ａ）に示すように、有機ＥＬ素子にはガ
ラス基板１０１の外部側の面上に反射防止フィルタ１０
６が形成されている。また、図５（ｂ）は、図５（ａ）
中の矢印Ａに示す部分の拡大図であり、同図からわかる
ように、反射防止フィルタ１０６は、例えば、偏光子１
０６ａ及び１／４波長板１０６ｂが積層されて形成され
ている。FIG. 5 shows an organic E having an anti-reflection filter.
It is the principal part block diagram which showed an example of the L element, (a) shows the principal part sectional drawing, (b) has shown the partial enlarged view of (a). As shown in FIG. 5A, the organic EL element has an antireflection filter 10 on the outer surface of the glass substrate 101.
6 are formed. FIG. 5 (b) is the same as FIG.
FIG. 2 is an enlarged view of a portion indicated by an arrow A in the middle, and as can be seen from FIG.
06a and the 波長 wavelength plate 106b are laminated.
【０００６】また、図６は、反射防止フィルタ１０６が
有する機能を、有機ＥＬディスプレイパネル内の各層を
反射又は通過する光の偏光状態を光の進路に沿って示し
た図であり、図６（ａ）は外部光が有機ＥＬディスプレ
イパネル内に入射して再び反射光となって放射されるま
での偏光状態を示し、図６（ｂ）は、有機ＥＬディスプ
レイパネルの発光層１０３によって発せられる発光光
（ＥＬ光）が外部に放射されるまでの偏光状態を示して
いる。FIG. 6 is a diagram showing the function of the antireflection filter 106, showing the polarization state of light reflected or passing through each layer in the organic EL display panel along the light path. FIG. 6A shows a state of polarization until external light enters the organic EL display panel and is emitted as reflected light again. FIG. 6B shows light emission emitted by the light emitting layer 103 of the organic EL display panel. It shows the polarization state until light (EL light) is emitted to the outside.
【０００７】図６（ａ）からわかるように、有機ＥＬデ
ィスプレイパネル内に入射した無偏光の外部光は、直線
偏光成分Ａだけが偏光子１０６ａを通り抜け、１／４波
長板１０６ｂで円偏光に変換され、ガラス基板１０１に
入射する。ガラス基板１０１に入射した光は、その後、
陰極１０４で反射して、再度１／４波長板１０６ｂに入
射する。このとき１／４波長板１０６ｂに入射した光
は、１／４波長板１０６ｂによって直線偏光成分Ａと垂
直な直線偏光成分Ｂに変換されるため、偏光子を通り抜
けられない。As can be seen from FIG. 6 (a), only the linearly polarized light component A of the unpolarized external light incident on the organic EL display panel passes through the polarizer 106a, and is converted into circularly polarized light by the quarter-wave plate 106b. The light is converted and incident on the glass substrate 101. The light incident on the glass substrate 101 is then
The light is reflected by the cathode 104 and again enters the quarter-wave plate 106b. At this time, the light incident on the １ ／ wavelength plate 106b is converted into a linearly polarized light component B perpendicular to the linearly polarized light component A by the 波長 wavelength plate 106b, and thus cannot pass through the polarizer.
【０００８】また、図６（ｂ）からわかるように、有機
ＥＬディスプレイパネルの発光層１０３によって発せら
れるＥＬ光を無偏光光とした場合、ＥＬ光は、１／４波
長板１０６ｂに入射した後、無偏光のまま１／４波長板
１０６ｂを通り抜けて偏光子１０６ａに入射する。この
とき偏光子１０６ａに入射した光は、偏光子１０６ａに
よって直線偏光成分Ａだけが偏光子１０６ａを通り抜け
た後外部に放射される。Further, as can be seen from FIG. 6B, when the EL light emitted from the light emitting layer 103 of the organic EL display panel is unpolarized light, the EL light is incident on the quarter-wave plate 106b. Pass through the quarter-wave plate 106b with no polarization and enter the polarizer 106a. At this time, the light incident on the polarizer 106a is emitted to the outside after only the linearly polarized light component A passes through the polarizer 106a by the polarizer 106a.
【０００９】ここで、直線偏光成分Ａは、無偏光光であ
るＥＬ光の偏光成分を直交する２つの偏光成分（Ａ、
Ｂ）に分けた場合の一方の偏光成分に相当するので、外
部に放射される光は、無偏光光における光量の約半分に
相当する光量となる。Here, the linearly polarized light component A is composed of two polarized light components (A, A) orthogonal to the polarized light component of the non-polarized light EL light.
Since it corresponds to one polarized light component when divided into B), the amount of light emitted to the outside is equivalent to about half of the amount of unpolarized light.
【００１０】反射防止フィルタ１０６はこのように形成
されるので、有機ＥＬディスプレイパネル内に入射した
無偏光の外部光による反射光が遮られ、ＥＬ光の一部
（ここでは直線偏光成分Ａ）だけが外部に放射されるこ
ととなり、結果的に外部光による有機ＥＬディスプレイ
パネルの表示コントラストの低下を防いでいる。Since the anti-reflection filter 106 is formed in this manner, reflected light by unpolarized external light incident on the organic EL display panel is blocked, and only a part of the EL light (here, the linearly polarized light component A) is blocked. Is radiated to the outside, and as a result, a decrease in the display contrast of the organic EL display panel due to the external light is prevented.
【００１１】[0011]
【発明が解決しようとする課題】ところが、従来の場
合、このような反射防止フィルタ１０６が設けられた有
機ＥＬディスプレイパネルを製造しようとすると、ガラ
ス基板１０１の一方の面上に陽極１０２、発光層１０
３、陰極１０４等の各層を順次成膜して積層した後、ガ
ラス基板１０１の他方の面上に反射防止フィルタ１０６
を接着剤等により固定する等して設ける作業が必要なた
め、その製造工程が繁雑になり、製造作業のフルオート
メーション化が困難となる。However, in the prior art, when an organic EL display panel provided with such an antireflection filter 106 is to be manufactured, an anode 102 and a light emitting layer are formed on one surface of a glass substrate 101. 10
3. After the layers such as the cathode 104 are sequentially formed and laminated, the anti-reflection filter 106 is formed on the other surface of the glass substrate 101.
It is necessary to perform an operation such as fixing with an adhesive or the like, which complicates the manufacturing process and makes it difficult to fully automate the manufacturing operation.
【００１２】また、上述したように、従来の反射防止フ
ィルタ１０６は、外部光の陰極１０４による反射を抑え
ることはできるが、ガラス基板１０１に到達したＥＬ光
の約半分は反射防止フィルタ１０６を通過する際に損失
となってしまうので（ＥＬ光の取出し効率を充分に確保
することが困難であり）、発光光（ＥＬ光）の輝度が低
下する。Further, as described above, the conventional anti-reflection filter 106 can suppress the reflection of external light by the cathode 104, but about half of the EL light reaching the glass substrate 101 passes through the anti-reflection filter 106. In such a case, a loss occurs (it is difficult to ensure sufficient extraction efficiency of the EL light), and the luminance of the emitted light (EL light) is reduced.
【００１３】本発明は上述の問題点に鑑みなされたもの
であり、簡単な製造工程により、輝度特性に優れ、表示
コントラストの低下のない発光ディスプレイパネルを提
供することを目的とする。The present invention has been made in view of the above-described problems, and has as its object to provide a light-emitting display panel which is excellent in luminance characteristics and does not lower display contrast by a simple manufacturing process.
【００１４】[0014]
【課題を解決するための手段】請求項１記載の発明は、
透明なガラス基板上に少なくとも透明電極層、発光層、
金属電極層、が順次積層されると共に、該発光層から発
光された光をガラス基板を通じて外部に放射する発光デ
ィスプレイパネルにおいて、ガラス基板と透明電極層と
の間に多層膜を介在させることを特徴とする。According to the first aspect of the present invention,
At least a transparent electrode layer on a transparent glass substrate, a light emitting layer,
In a light emitting display panel in which metal electrode layers are sequentially laminated and light emitted from the light emitting layer is emitted to the outside through a glass substrate, a multilayer film is interposed between the glass substrate and the transparent electrode layer. And
【００１５】また、請求項２記載の発明は、請求項１に
記載の発光ディスプレイパネルにおいて、多層膜は、透
明電極層及び発光層と共に、ガラス基板を通じて入射さ
れた外部光が金属電極層で反射されて再度ガラス基板を
通じて外部に放射されることを防止する反射防止手段を
構成することを特徴とする。According to a second aspect of the present invention, in the light emitting display panel according to the first aspect, the multilayer film, together with the transparent electrode layer and the light emitting layer, reflects external light incident through the glass substrate on the metal electrode layer. And an anti-reflection means for preventing the radiation to the outside through the glass substrate.
【００１６】また、請求項３記載の発明は、透明なガラ
ス基板上に少なくとも透明電極層、有機正孔輸送層、有
機発光層、有機電子輸送層、金属電極層が順次積層さ
れ、該有機発光層から発光された光をガラス基板を通じ
て外部に放射する発光ディスプレイパネルにおいて、ガ
ラス基板と透明電極層との間に多層膜を介在させること
を特徴とする。According to a third aspect of the present invention, at least a transparent electrode layer, an organic hole transport layer, an organic light emitting layer, an organic electron transport layer, and a metal electrode layer are sequentially laminated on a transparent glass substrate. In a light-emitting display panel that emits light emitted from a layer through a glass substrate to the outside, a multilayer film is interposed between the glass substrate and the transparent electrode layer.
【００１７】また、請求項４記載の発明は、請求項３に
記載の発光ディスプレイパネルにおいて、多層膜は、透
明電極層、有機正孔輸送層、有機発光層及び有機電子輸
送層と共に、ガラス基板を通じて入射された外部光が金
属電極層で反射されて再度ガラス基板を通じて外部に放
射されることを防止する反射防止手段を構成することを
特徴とする。According to a fourth aspect of the present invention, in the light-emitting display panel according to the third aspect, the multilayer film is a glass substrate together with a transparent electrode layer, an organic hole transport layer, an organic light-emitting layer, and an organic electron transport layer. An anti-reflection means is configured to prevent external light incident through the glass electrode layer from being reflected by the metal electrode layer and radiated outside again through the glass substrate.
【００１８】また、請求項５記載の発明は、請求項１乃
至４に記載の発光ディスプレイパネルにおいて、多層膜
は、金属膜を含んで構成されることを特徴とする。According to a fifth aspect of the present invention, in the light emitting display panel according to the first to fourth aspects, the multilayer film includes a metal film.
【００１９】また、請求項６記載の発明は、請求項１乃
至５に記載の発光ディスプレイパネルにおいて、多層膜
は、ガラス基板を通じて入射した外部光の一部を反射す
る反射光路を形成するものであり、当該反射光路に沿っ
て進行する外部光と、多層膜を透過した後に他の層で反
射して形成される他の反射光路に沿って進行する外部光
とを互いに干渉させることにより、ガラス基板を通じて
入射した外部光による反射光量を少なくすることを特徴
とする。According to a sixth aspect of the present invention, in the light emitting display panel according to any one of the first to fifth aspects, the multilayer film forms a reflection optical path for reflecting a part of external light incident through the glass substrate. The external light traveling along the reflected light path and the external light traveling along another reflected light path formed by being reflected by another layer after passing through the multilayer film and interfering with each other, the glass It is characterized in that the amount of reflected light by external light incident through the substrate is reduced.
【００２０】[0020]
【作用】本発明によれば、ガラス基板と透明電極層との
間に多層膜を介在させるようにしたので、ガラス基板の
一方の面上に陽極、発光層、陰極等の各層と共に多層膜
を順次成膜して積層することができ、従来に比べて簡単
な製造工程により外部光の反射防止機能を有する発光デ
ィスプレイパネルを実現することができる。According to the present invention, since a multilayer film is interposed between the glass substrate and the transparent electrode layer, the multilayer film is formed on one surface of the glass substrate together with the anode, light emitting layer, cathode, and other layers. Films can be sequentially formed and laminated, and a light-emitting display panel having an anti-reflection function for external light can be realized by a simpler manufacturing process than in the related art.
【００２１】また、ガラス基板と透明電極層との間に介
在する多層膜は、反射防止手段によって、ガラス基板を
通じて入射した外部光の一部を反射する反射光路を形成
し、当該反射光路に沿って進行する外部光と、多層膜を
透過した後に他の層で反射して形成される他の反射光路
に沿って進行する外部光とを互いに干渉させることによ
り、ガラス基板を通じて入射した外部光による反射光量
を少なくするので、外部光が金属電極層で反射すること
による悪影響を抑えることができると共に、発光光の取
出し効率に関しても従来の反射防止フィルタを備えた発
光ディスプレイパネルより向上させることが可能とな
る。したがって、簡単な製造工程により、輝度特性に優
れ、表示コントラストの低下のない発光ディスプレイパ
ネルを提供することができる。Further, the multilayer film interposed between the glass substrate and the transparent electrode layer forms a reflection optical path for reflecting a part of the external light incident through the glass substrate by the antireflection means. The external light traveling through the glass substrate interferes with the external light that travels along the reflected light path that is formed by being reflected by another layer after being transmitted through the multilayer film. Since the amount of reflected light is reduced, it is possible to suppress the adverse effects of external light reflected by the metal electrode layer, and it is also possible to improve the efficiency of extracting emitted light from a light emitting display panel having a conventional antireflection filter. Becomes Therefore, it is possible to provide a light-emitting display panel which is excellent in luminance characteristics and does not lower display contrast by a simple manufacturing process.
【００２２】[0022]
【発明の実施の形態】次に、本発明に好適な実施形態に
ついて図面に基づいて以下に説明する。図１は、本発明
の一実施形態における発光ディスプレイに用いられる有
機ＥＬ素子の主要部概略断面図である。なお、同図中、
先の図４に示す従来の有機ＥＬ素子と同等部分について
は、同一の符号を付してある。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of a main part of an organic EL element used in a light emitting display according to an embodiment of the present invention. In the figure,
The same parts as those of the conventional organic EL element shown in FIG. 4 are denoted by the same reference numerals.
【００２３】図１に示すように、有機ＥＬ素子には、透
明なガラス基板１０１の一方の面上に多層膜１が形成さ
れ、さらに多層膜１上には透明な陽極１０２が形成され
ている。さらに陽極１０２上には有機発光層や有機正孔
輸送層等から成る発光層１０３が形成されて、さらにそ
の上にはＡｌ等の金属からなる陰極１０４が真空蒸着等
によって形成されている。As shown in FIG. 1, in the organic EL device, a multilayer film 1 is formed on one surface of a transparent glass substrate 101, and a transparent anode 102 is formed on the multilayer film 1. . Further, a light emitting layer 103 made of an organic light emitting layer, an organic hole transporting layer, or the like is formed on the anode 102, and a cathode 104 made of a metal such as Al is formed thereon by vacuum evaporation or the like.
【００２４】また陰極１０４は所定の形状にパターニン
グされていて、陰極１０４と陽極１０２間に接続された
駆動源１０５から供給される電圧によって両極間に位置
する発光層１０３に電流が流れ、陰極１０４及び陽極１
０２のパターン形状に応じて発光光（ＥＬ光）を出射
し、透明なガラス基板１０１を介して外部に放射するこ
とにより、陽極１０２のパターン形状が発光表示され
る。The cathode 104 is patterned into a predetermined shape, and a current flows through the light emitting layer 103 located between the two electrodes by a voltage supplied from a driving source 105 connected between the cathode 104 and the anode 102. And anode 1
Emission light (EL light) is emitted in accordance with the pattern shape of No. 02, and emitted to the outside via the transparent glass substrate 101, whereby the pattern shape of the anode 102 is luminescently displayed.
【００２５】本発明の一実施形態における発光ディスプ
レイに用いられる有機ＥＬ素子はこのように構成され、
多層膜１を含めた陽極１０２、発光層１０３、陰極１０
４の各層を、図１に示すようにガラス基板１０１に順次
成膜していくことで形成される。つまり、多層膜１は、
一連の成膜積層工程の中で形成することができる。The organic EL device used in the light emitting display according to one embodiment of the present invention is configured as described above.
Anode 102, light-emitting layer 103, and cathode 10 including multilayer film 1
Each layer of No. 4 is formed by sequentially forming a film on the glass substrate 101 as shown in FIG. That is, the multilayer film 1
It can be formed in a series of film deposition and lamination steps.
【００２６】次に、多層膜１について詳述する。多層膜
１は、金属膜を含む複数の薄膜が積層されて構成され
る。多層膜を構成する各層の薄膜の厚みと屈折率は、陽
極１０２、発光層１０３が有する有機発光層や有機正孔
輸送層や有機電子輸送層、及び陰極１０４の各厚み、屈
折率（又は吸収率）を考慮した上で以下の各項目（ａ．
ｂ．ｃ．）が示す条件を満すように選定される。なお、
多層膜１の各層の屈折率は、上記各層に用いる材料の選
定により設定される。Next, the multilayer film 1 will be described in detail. The multilayer film 1 is configured by stacking a plurality of thin films including a metal film. The thickness and refractive index of the thin film of each layer constituting the multilayer film are determined by the thickness, refractive index (or absorption) of the organic light emitting layer, organic hole transport layer, organic electron transport layer, and cathode 104 included in the anode 102 and the light emitting layer 103. Rate) in consideration of the following items (a.
b. c. ) Are selected so as to satisfy the conditions shown in (1). In addition,
The refractive index of each layer of the multilayer film 1 is set by selecting a material used for each layer.
【００２７】ａ．外部光の反射率の低減 外部から発光ディスプレイに入射した光が、多層膜１の
各層、陽極１０２、発光層１０３が有する有機発光層や
有機正孔輸送層や有機電子輸送層、及び陰極１０４で反
射して形成される各光路（反射光路）における光量、位
相を想定し、これらの反射光が干渉によって互いに打消
し合うことにより各反射光路を進行する反射光トータル
の光量がほぼ０となるようにするか又は、反射光のトー
タル光量が少なくとも多層膜１を設けない有機ＥＬ素子
（図４に相当）の場合と比べて低減するように設定す
る。A. Reduction of reflectance of external light Light incident on the light-emitting display from the outside is reflected on each layer of the multilayer film 1, the anode 102, the organic light-emitting layer, the organic hole transport layer, the organic electron-transport layer, and the cathode 104 included in the light-emitting layer 103. Assuming the amount of light and the phase in each optical path formed by reflection (reflected optical path), these reflected lights cancel each other out by interference, so that the total amount of reflected light traveling in each reflected optical path becomes almost zero. Alternatively, the total amount of reflected light is set to be lower than at least the case of an organic EL element (corresponding to FIG. 4) in which the multilayer film 1 is not provided.
【００２８】この場合、多層膜１に適度な吸収率を有す
る金属膜からなる薄膜を設けて、金属膜を含む反射光路
の光量のうち金属膜を透過する光量と、金属膜上を反射
する光量の割合を調整することにより、陰極１０４での
反射を含む反射光路の光量が、他の反射光路の光量に比
べて極端に多くならないようにすることができ、互いの
反射光路を進行する反射光の干渉による打消しが容易と
なる。In this case, a thin film made of a metal film having an appropriate absorptivity is provided in the multilayer film 1 so that the amount of light transmitted through the metal film and the amount of light reflected on the metal film out of the amount of light reflected on the optical path including the metal film. By adjusting the ratio, the amount of light in the reflected light path including the reflection at the cathode 104 can be prevented from becoming extremely large as compared with the amounts of light in the other reflected light paths, and the reflected light traveling through the reflected light paths of each other can be prevented. Can be easily canceled by interference.
【００２９】多層膜１がこの項目を満足することによ
り、外部から発光ディスプレイに入射した光は、発光デ
ィスプレイ内の各層を透過又は反射した後、互いに干渉
又は吸収され、再び発光ディスプレイのガラス基板１０
１から外部に放出されるのを抑制される。When the multilayer film 1 satisfies this item, light incident on the light-emitting display from the outside is transmitted or reflected by each layer in the light-emitting display, and then interferes or is absorbed with each other.
1 is suppressed from being released to the outside.
【００３０】ｂ．発光光（ＥＬ光）の取出し効率の向上 発光層１０３から出射する発光光（ＥＬ光）は、上記各
層における透過、反射により複数の光路に分岐するが、
これらが干渉して有機ＥＬ素子の外部に放射する光量
が、少なくとも多層膜１を設けない有機ＥＬ素子（図４
に相当）の場合と比べて低下しないように（又は、望ま
しくは有機ＥＬ素子の外部に放射する光量が増幅するよ
うに）、即ち発光光（ＥＬ光）の取出し効率を維持又は
向上するように、多層膜１の各薄膜の厚み、屈折率（又
は吸収率）を設定する。B. Improvement of extraction efficiency of emitted light (EL light) Emitted light (EL light) emitted from the light emitting layer 103 is branched into a plurality of optical paths by transmission and reflection in each layer.
The amount of light radiated to the outside of the organic EL element due to interference between them is at least the organic EL element without the multilayer film 1 (FIG. 4).
) So as not to decrease (or desirably, to amplify the amount of light radiated to the outside of the organic EL element), that is, to maintain or improve the efficiency of taking out the emitted light (EL light). The thickness and the refractive index (or absorptance) of each thin film of the multilayer film 1 are set.
【００３１】なお、多層膜１に、上述した金属膜からな
る薄膜を設ける場合、その金属膜による光の吸収作用を
受けて発光光（ＥＬ光）の取出し効率が低下するので、
反射防止との兼ね合いも考慮して好適な多層膜１の各薄
膜の厚み、屈折率（又は吸収率）を設定する。When a thin film made of the above-described metal film is provided on the multilayer film 1, the efficiency of taking out emitted light (EL light) is reduced due to the light absorbing effect of the metal film.
The thickness and refractive index (or absorptance) of each thin film of the multilayer film 1 are set in consideration of the balance with antireflection.
【００３２】多層膜１がこの項目を満足することによ
り、多層膜１がガラス基板１０１と陽極１０２の間に介
在しても、発光層１０３が発する発光光（ＥＬ光）がガ
ラス基板１０１から放射される場合に、その光量は従来
に比べて増幅することはあるが低下することはない。When the multilayer film 1 satisfies this item, the emission light (EL light) emitted from the light emitting layer 103 is emitted from the glass substrate 101 even if the multilayer film 1 is interposed between the glass substrate 101 and the anode 102. In this case, the light amount may be amplified but not reduced as compared with the conventional case.
【００３３】ｃ．外部光反射率の角度特性について 外部光の反射率については、ガラス基板１０１と空気の
臨界角（４１度）以下の角度範囲において、上記項目
ａ．及びｂ．が示す条件が満たされるように多層膜１を
設定する。臨界角以上の角度を有する外部光は、ガラス
基板１０１で全反射されるためガラス基板１０１の内部
に入り込むことができないからである。C. Angle Characteristics of External Light Reflectance Regarding the external light reflectivity, the above item a.1 is set in the angle range not more than the critical angle (41 degrees) between the glass substrate 101 and air. And b. The multilayer film 1 is set so that the condition shown by is satisfied. This is because external light having an angle equal to or larger than the critical angle cannot enter the glass substrate 101 because it is totally reflected by the glass substrate 101.
【００３４】発明者は、既存の各層に対し、多層膜１の
厚さ及び屈折率を種々の材料を用いて、発光ディスプレ
イに入射する外部光の反射率及び発光層１０３が発する
発光光（ＥＬ光）の透過率のシミュレーションを行った
結果、多層膜１を、図２に示す厚さ、屈折率（材料）に
設定した場合に優れた効果を有することが判明した。The inventor uses various materials for the thickness and the refractive index of the multilayer film 1 for each of the existing layers to determine the reflectance of external light incident on the light emitting display and the light emitted from the light emitting layer 103 (EL). As a result of simulation of transmittance of light, it was found that the multilayer film 1 had an excellent effect when the thickness and the refractive index (material) were set as shown in FIG.
【００３５】図２は、上記シミュレーションに用いた有
機ＥＬ素子の各層の材料、厚さ、屈折率を示した図であ
り、シミュレーションを行うに際し、その他の条件とし
て、外部光、発光層１０３の発光光（ＥＬ光）の波長を
５５０ｎｍに設定した。同図に示すように、多層膜１に
用いられるＡｕ、Ｃｒの各材料による層は金属層であ
り、光の顕著な吸収作用を伴う媒質であるため、複素屈
折率で表されている。また、発光層１０３中のＣｕ−Ｐ
ｃは正孔注入層、ＮＰＡＢＰは正孔輸送層、Ａｌｑ3 は
緑色発光層をそれぞれ示している。FIG. 2 is a diagram showing the material, thickness, and refractive index of each layer of the organic EL device used in the above simulation. In performing the simulation, other conditions include external light and light emission of the light emitting layer 103. The wavelength of light (EL light) was set to 550 nm. As shown in the figure, the layers made of Au and Cr materials used for the multilayer film 1 are metal layers, which are media having a remarkable light absorbing action, and are represented by a complex refractive index. Further, Cu—P in the light emitting layer 103
c indicates a hole injection layer, NPABP indicates a hole transport layer, and Alq 3 indicates a green light emitting layer.
【００３６】図３に上記シミュレーション結果を示す。
図３は、図２の各条件に設定された有機ＥＬ素子の外部
光の反射率及び、ＥＬ光の透過率を、それぞれガラス基
板１０１からの放射角度に対し表したグラフである。同
図からわかるように、外部光が入射する臨界角よりも小
さい角度においては、外部光の反射率はほぼ０に近いも
のとなり、有機ＥＬ素子に入射した外部光は、再び発光
ディスプレイのガラス基板１０１から外部に放出される
のを抑制されていることがわかる。また、ガラス基板１
０１から発せられる発光光（ＥＬ光）は、放射角度６０
度までは、透過率がほぼ一定であり、表示に必要な輝度
が充分確保されていることがわかる。FIG. 3 shows the simulation results.
FIG. 3 is a graph showing the reflectance of the organic EL element and the transmittance of the EL light of the organic EL element set under the respective conditions of FIG. As can be seen from the figure, at an angle smaller than the critical angle at which the external light is incident, the reflectance of the external light is almost zero, and the external light incident on the organic EL element is again reflected on the glass substrate of the light emitting display. It can be seen that the emission from 101 is suppressed to the outside. Also, the glass substrate 1
01 emits light (EL light) at an emission angle of 60
It can be seen that the transmittance is almost constant up to the degree, and the luminance required for display is sufficiently ensured.
【００３７】[0037]
【発明の効果】本発明は以上のように構成したため、ガ
ラス基板と透明電極層との間に多層膜を介在させるよう
にしたので、ガラス基板の一方の面上に陽極、発光層、
陰極等の各層と共に多層膜を順次成膜して積層すること
ができ、従来に比べて簡単な製造工程により外部光の反
射防止機能を有する発光ディスプレイパネルを実現する
ことができる。According to the present invention having the above construction, a multilayer film is interposed between the glass substrate and the transparent electrode layer.
A multilayer film can be sequentially formed and laminated together with each layer such as a cathode, and a light-emitting display panel having an anti-reflection function for external light can be realized by a simpler manufacturing process than in the related art.
【００３８】また、ガラス基板と透明電極層との間に介
在する多層膜は、反射防止手段によって、ガラス基板を
通じて入射した外部光の一部を反射する反射光路を形成
し、当該反射光路に沿って進行する外部光と、多層膜を
透過した後に他の層で反射して形成される他の反射光路
に沿って進行する外部光とを互いに干渉させることによ
り、ガラス基板を通じて入射した外部光による反射光量
を少なくするので、外部光が金属電極層で反射すること
による悪影響を抑えることができると共に、発光光の取
出し効率に関しても従来の反射防止フィルタを備えた発
光ディスプレイパネルより向上させることが可能とな
る。したがって、簡単な製造工程により、輝度特性に優
れ、表示コントラストの低下のない発光ディスプレイパ
ネルを提供することができる。Further, the multilayer film interposed between the glass substrate and the transparent electrode layer forms a reflection optical path for reflecting a part of the external light incident through the glass substrate by the anti-reflection means. The external light traveling through the glass substrate interferes with the external light that travels along the reflected light path that is formed by being reflected by another layer after being transmitted through the multilayer film. Since the amount of reflected light is reduced, it is possible to suppress the adverse effects of external light reflected by the metal electrode layer, and it is also possible to improve the efficiency of extracting emitted light from a light emitting display panel having a conventional antireflection filter. Becomes Therefore, it is possible to provide a light-emitting display panel which is excellent in luminance characteristics and does not lower display contrast by a simple manufacturing process.
【図１】本発明の一実施形態における発光ディスプレイ
に用いられる有機ＥＬ素子の主要部概略断面図である。FIG. 1 is a schematic sectional view of a main part of an organic EL element used for a light emitting display according to an embodiment of the present invention.
【図２】外部光の反射率及びＥＬ光の透過率のシミュレ
ーションに用いた有機ＥＬ素子の各層の材料、厚さ、屈
折率を示した図である。FIG. 2 is a diagram showing a material, a thickness, and a refractive index of each layer of an organic EL element used in a simulation of a reflectance of external light and a transmittance of EL light.
【図３】外部光の反射率及びＥＬ光の透過率のシミュレ
ーション結果を示す図である。FIG. 3 is a diagram showing simulation results of the reflectance of external light and the transmittance of EL light.
【図４】従来の有機ＥＬ素子の概略断面図である。FIG. 4 is a schematic sectional view of a conventional organic EL element.
【図５】反射防止フィルタを設けた有機ＥＬ素子の一例
を示した主要部構成図である。FIG. 5 is a main part configuration diagram showing an example of an organic EL device provided with an antireflection filter.
【図６】反射防止フィルタが有する機能を、有機ＥＬデ
ィスプレイパネル内の各層を反射又は通過する光の偏光
状態を光の進路に沿って示した図である。FIG. 6 is a diagram illustrating a function of an antireflection filter and a polarization state of light reflected or transmitted through each layer in an organic EL display panel along a light path.
１・・・・・多層膜 １０１・・・ガラス基板 １０２・・・陽極 １０３・・・発光層 １０４・・・陰極 １０５・・・駆動源 １０６・・・反射防止フィルタ １０６ａ・・偏光子 １０６ｂ・・１／４波長板 1 multilayer film 101 glass substrate 102 anode 103 light emitting layer 104 cathode 105 driving source 106 antireflection filter 106a polarizer 106b・ 1/4 wavelength plate
Claims (6)
極層、発光層、金属電極層、が順次積層されると共に、
該発光層から発光された光を前記ガラス基板を通じて外
部に放射する発光ディスプレイパネルにおいて、 前記ガラス基板と前記透明電極層との間に多層膜を介在
させることを特徴とする発光ディスプレイパネル。At least a transparent electrode layer, a light emitting layer, and a metal electrode layer are sequentially laminated on a transparent glass substrate,
A light emitting display panel that emits light emitted from the light emitting layer to the outside through the glass substrate, wherein a multilayer film is interposed between the glass substrate and the transparent electrode layer.
光層と共に、前記ガラス基板を通じて入射された外部光
が前記金属電極層で反射されて再度前記ガラス基板を通
じて外部に放射されることを防止する反射防止手段を構
成することを特徴とする、請求項１に記載の発光ディス
プレイパネル。2. The multi-layer film, together with the transparent electrode layer and the light-emitting layer, is configured so that external light incident through the glass substrate is reflected by the metal electrode layer and radiated outside again through the glass substrate. The light-emitting display panel according to claim 1, wherein the light-emitting display panel comprises anti-reflection means for preventing light.
極層、有機正孔輸送層、有機発光層、有機電子輸送層、
金属電極層が順次積層され、該有機発光層から発光され
た光を前記ガラス基板を通じて外部に放射する発光ディ
スプレイパネルにおいて、 前記ガラス基板と前記透明電極層との間に多層膜を介在
させることを特徴とする発光ディスプレイパネル。3. On a transparent glass substrate, at least a transparent electrode layer, an organic hole transport layer, an organic light emitting layer, an organic electron transport layer,
In a light-emitting display panel in which metal electrode layers are sequentially stacked and light emitted from the organic light-emitting layer is radiated to the outside through the glass substrate, a multilayer film is interposed between the glass substrate and the transparent electrode layer. Light emitting display panel featuring.
機正孔輸送層、前記有機発光層及び前記有機電子輸送層
と共に、前記ガラス基板を通じて入射された外部光が前
記金属電極層で反射されて再度前記ガラス基板を通じて
外部に放射されることを防止する反射防止手段を構成す
ることを特徴とする、請求項３に記載の発光ディスプレ
イパネル。4. The multilayer film, together with the transparent electrode layer, the organic hole transport layer, the organic light emitting layer and the organic electron transport layer, reflects external light incident through the glass substrate on the metal electrode layer. 4. The light emitting display panel according to claim 3, wherein the light emitting display panel comprises an anti-reflection means for preventing the light from being radiated outside through the glass substrate again.
ることを特徴とする、請求項１乃至４に記載の発光ディ
スプレイパネル。5. The light emitting display panel according to claim 1, wherein the multilayer film includes a metal film.
入射した外部光の一部を反射する反射光路を形成するも
のであり、当該反射光路に沿って進行する外部光と、前
記多層膜を透過した後に他の層で反射して形成される他
の反射光路に沿って進行する外部光とを互いに干渉させ
ることにより、前記ガラス基板を通じて入射した外部光
による反射光量を少なくすることを特徴とする、請求項
１乃至５に記載の発光ディスプレイパネル。6. The multilayer film forms a reflected light path that reflects a part of the external light incident through the glass substrate, and transmits the external light traveling along the reflected light path and the multilayer film. Then, by interfering with external light that travels along another reflected light path formed by being reflected by another layer, the amount of external light incident through the glass substrate is reduced. The light-emitting display panel according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9076532A JPH10255978A (en) | 1997-03-12 | 1997-03-12 | Luminescent display panel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9076532A JPH10255978A (en) | 1997-03-12 | 1997-03-12 | Luminescent display panel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10255978A true JPH10255978A (en) | 1998-09-25 |
Family
ID=13607897
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9076532A Pending JPH10255978A (en) | 1997-03-12 | 1997-03-12 | Luminescent display panel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10255978A (en) |
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