JP2004014128A - Planar light emitting device - Google Patents

Planar light emitting device Download PDF

Info

Publication number
JP2004014128A
JP2004014128A JP2002161542A JP2002161542A JP2004014128A JP 2004014128 A JP2004014128 A JP 2004014128A JP 2002161542 A JP2002161542 A JP 2002161542A JP 2002161542 A JP2002161542 A JP 2002161542A JP 2004014128 A JP2004014128 A JP 2004014128A
Authority
JP
Japan
Prior art keywords
transparent electrode
electrode
organic
light emitting
auxiliary electrode
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.)
Granted
Application number
JP2002161542A
Other languages
Japanese (ja)
Other versions
JP3864851B2 (en
Inventor
Kenji Nishigaki
西垣　研治
Toshiki Inoue
井上　敏樹
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Industries Corp
Original Assignee
Toyota Industries Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toyota Industries Corp filed Critical Toyota Industries Corp
Priority to JP2002161542A priority Critical patent/JP3864851B2/en
Publication of JP2004014128A publication Critical patent/JP2004014128A/en
Application granted granted Critical
Publication of JP3864851B2 publication Critical patent/JP3864851B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar light emitting device using an organic electro-luminescence element, capable of suppressing unevenness of luminance. <P>SOLUTION: The organic electro-luminescence element 17 is used for the back light 10 of a transmission liquid crystal panel 1. An auxiliary electrode 12 having lower resistance than that of a transparent electrode 13 is electrically connected to the transparent electrode 13 of the organic electro-luminescence element 17. The auxiliary electrode is disposed so as to make a lattice shape in conformity with the picture element pitch of the transmission liquid crystal panel 1. In addition, the auxiliary electrode 12 is disposed on the surface of the transparent electrode 13 opposite to an organic electro-luminescence element layer 14 acting as a luminescent layer, among the surfaces of the transparent electrode 13. Accordingly, any difference in voltage is hardly caused between a part close to the connection terminal of the transparent electrode 13 and a part away from it, and unevenness of luminance can be suppressed. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、有機ＥＬ素子を用いた面状発光装置に関するものである。
【０００２】
【従来の技術】
従来の発光装置は、電球、蛍光管といったもので熱を伴って光を発生するというものであった。またその形状は立体的であるので、特に液晶ディスプレイのバックライトに用いる場合は、一般に導光板と共に用いられ、液晶ディスプレイの薄型化、小型化が困難であった。
【０００３】
一方、近年の技術開発で、有機ＥＬ素子の長寿命化、高効率化の研究が進み、薄膜状に形成されたの面状発光装置として利用が考えられている。有機ＥＬ素子をはじめ、発光素子と透明電極を使用した光源装置には透明電極としてＩＴＯ（インジウム錫酸化物）やＺｎＯ（酸化亜鉛）等が主に用いられている。
【０００４】
【発明が解決しようとする課題】
ところが、前記透明電極は電気抵抗値が十分低くない。従って、接続端子から近い部分と遠い部分で電気抵抗値の差が大きくなり、電流値についても差が大きくなる。有機ＥＬ素子の発光輝度はその電流値に影響される為、発光輝度にムラが発生する。
【０００５】
特開平８−１８０９７４号公報には、ＥＬディスプレイの透明電極に補助電極を形成することが開示されている。これは透明電極がストライプ状になっており、接続端子に近い画素と遠い画素との間で発生する発光輝度のムラを抑制するために、補助電極を配設したものである。
【０００６】
有機ＥＬ素子を面状発光装置として利用する場合には、特開平８−１８０９７４号公報で開示されているストライプ状の透明電極よりさらに広い発光面積で使用されるため、透明電極の電気抵抗値の問題が顕著になる。
【０００７】
本発明は以上の問題に鑑みてなされたものであって、その目的は、輝度のムラを抑制することができる面状発光装置を提供する事である。
【０００８】
【課題を解決するための手段】
前記の目的を達成するため、請求項１に記載の発明は、有機ＥＬ素子を用いた面状発光装置において、前記有機ＥＬ素子の透明電極に、前記透明電極より低抵抗な補助電極を電気的に接続している。従って補助電極により、透明電極の接続端子に近い部分と遠い部分との電気抵抗値の差が緩和され、面状の有機ＥＬ素子全体の輝度のムラを抑制できる。
【０００９】
請求項２に記載の発明は、請求項１に記載の発明において、前記補助電極が格子状に形成されている。従って、電気抵抗値の差がさらに緩和され、輝度のムラをさらに抑制できる。
【００１０】
請求項３に記載の発明は、請求項１又は請求項２に記載の発明において、前記補助電極が、前記透明電極の面のうち、発光層（有機ＥＬ層）と反対側の面に配設されている。従って、補助電極が、通常の厚さがおよそ１００ｎｍである有機ＥＬ層に覆われていない部分で短絡することがない。
【００１１】
請求項４に記載の発明は、透過型液晶パネルのバックライトに使用される有機ＥＬ素子を用いた面状発光装置において、前記有機ＥＬ素子の透明電極に、前記透明電極より低抵抗な補助電極を、透過型液晶パネルの画素ピッチに合わせて格子状に配設している。従って補助電極が画素と対応する位置に配設される事が無い状態で、液晶ディスプレイの画素間の輝度のムラを抑制する事ができる。
【００１２】
請求項５に記載の発明は、請求項１から請求項４のいずれか一項に記載の発明において、前記補助電極が接続端子から近い部分では太く、接続端子から遠い部分では細く形成されている。ここで、「接続端子から近い」とは、補助電極を経由して接続端子に至る距離が近いことを意味し、「接続端子から遠い」とは、補助電極を経由して接続端子に至る距離が遠いことを意味する。従って、接続端子に近い部分では電流値が高く発光が強いが、開口率は低い。一方、接続端子から遠い部分では電流値が低く発光が弱いが、開口率は高い。したがって、全体として輝度ムラを抑制できる。
【００１３】
【発明の実施の形態】
以下、本発明をパッシブ・マトリックス方式の透過型液晶表示装置のバックライトとして具体化した一実施の形態を図１に従って説明する。図１において上側が表示部であり表側とし、下側を裏側とする。
【００１４】
パッシブ・マトリックス方式の液晶パネル１は液晶９を挟んで表側に、偏向板２、基板３、カラーフィルタ４、透明電極５を有する。また、液晶９を挟んで裏側には偏向板６、基板７、走査電極８を有する。そして、液晶パネル１はその中央部に液晶９を有する。
【００１５】
基板３の表側には偏向板２が形成される。裏側にはストライプ状のカラーフィルタ４が複数本平行に形成され、さらにカラーフィルタ４と同様に透明電極５が形成されている。一方、基板７の裏側には偏向板６が形成される。表側には、カラーフィルタ４及び透明電極５と直行する方向に、ストライプ状の走査電極８が複数本平行に形成されている。そして、透明電極５と走査電極８の間に液晶９が配設され、基板３，７の間隔を一定に保った状態で、図示しないシール材によって貼り合わされている。よって透明電極５と走査電極８は液晶９を挟んで、その交差部分において画素を構成し、その画素はマトリックス状に配置されている。
【００１６】
基板３，７はともに透明で例えばガラス製である。また、透明電極５と走査電極８はともに透明でＩＴＯ（インジウム錫化合物）製である。
バックライト１０としての面状発光装置は、その面積が液晶パネル１とほぼ同じであり、基板１１、補助電極１２、透明電極１３、有機ＥＬ層１４、反射電極１５、基板１６を有している。
【００１７】
基板１１は、バックライト１０の液晶パネル１と面する表側であり、その裏側に補助電極１２が形成され、補助電極１２を覆う様に透明電極１３が形成されている。補助電極１２は透明電極１３と電気的に接続されている。補助電極１２は液晶パネル１の画素と重ならない位置に、画素ピッチに合わせて格子状に配設されている。一方、基板１６の表側には反射電極１５が形成されている。透明電極１３と反射電極１５の間に、有機ＥＬ層１４が形成されている。従って有機ＥＬ素子１７は、透明電極１３と有機ＥＬ層１４と反射電極１５から構成されている。基板１１と基板１６の間は、有機ＥＬ層１４へ、外部から水分や酸素の進入を防ぐため、図示しないシール材（例えば、エポキシ樹脂）で封止されている。
【００１８】
基板１１は透明で、例えばガラス製である。補助電極１２は透明電極１３より低抵抗であり、例えばアルミニウム製である。透明電極１３はＩＴＯ製である。有機ＥＬ層１４は、公知の構成のものが使用され例えば電子輸送層、発光層、正孔輸送層から構成される。また、有機ＥＬ層１４は白色発光層で構成されている。反射電極１５は金属電極で、例えばクロム製である。基板１６は例えばガラス製である。
【００１９】
次に上記のように構成された本実施の形態の作用について説明する。
液晶パネル１は図示しない駆動制御装置により透明電極５、走査電極８に電圧を印加して、所望の画素を透過可能とする。
【００２０】
一方バックライト１０は電源投入されると、透明電極１３と反射電極１５に印加され、有機ＥＬ素子が白色に発光する。発光した光は直接、もしくは反射電極１５に反射して、透明電極１３及び基板１１を通過して液晶パネル１へ達する。
【００２１】
液晶パネル１へ達した光のうち、透過可能になった画素部分への光のみが、液晶パネル１の表側に出てくる。このときカラーフィルタ４の図示しないＲ（赤）、Ｇ（緑）、Ｂ（青）の画素を通過し、その組み合わせにより所望の色が再現される。
【００２２】
このとき、透明電極１３は電気抵抗が十分低くないが、補助電極１２に電気的に接続されているため、透明電極１３の接続端子に近い部分と遠い部分で電圧差はほとんど無くなり、輝度のムラを抑制することができる。
【００２３】
本実施の形態では以下の効果を有する。
（１）　透明電極１３に格子状の補助電極１２が電気的に接続されているため、透明電極１３の接続端子に近い部分と遠い部分で電圧差はほとんど無くなり、輝度のムラを抑制することができる。
【００２４】
（２）　補助電極１２は液晶パネル１の画素ピッチに合わせて配設されているため、補助電極１２が液晶パネル１の画素と対応する位置に配設される事が無い状態で、液晶ディスプレイの画素間の輝度のムラを抑制することができる。
【００２５】
（３）　補助電極１２は、透明電極１３の面のうち、発光層である有機ＥＬ層１４と反対側の面に配設されている。従って、補助電極１２の断面が長方形状であっても、厚さ非常に薄い（通常およそ１００ｎｍ）有機ＥＬ層１４に覆われていない部分が生じることがなく、補助電極１２が反射電極１５と短絡することがない。
【００２６】
（４）　通常の陰極管と導光板を用いたバックライトより薄型化・小型化できる。
（５）　反射電極１５が有機ＥＬ層１４の片面全体に形成されている。従って、液晶パネル１と反対方向へ向かって発光する光は、全て反射電極１５に反射され、液晶パネル１へ射出する光量を多くできる。
【００２７】
実施の形態は前記に限らず、例えば次のように構成してもよい。
○　補助電極１２の格子は１画素ごとでなくてもよく、例えば複数画素ごとに対応するように設けてもよい。複数画素ごとでも、透明電極１３の接続端子に近い部分と遠い部分で電圧差がほとんど無くなり、輝度のムラを抑制することができる。
【００２８】
○　補助電極１２の格子は一定の画素ごとでなくてもよい。例えば、透明電極１３を流れる電流量が確保しにくい透明電極１３の接続端子から遠い部分では１画素ごととし、電流量が確保しやすい透明電極１３の接続端子から近い部分では複数画素ごととしてもよい。
【００２９】
○　補助電極１２は格子状でなくてもよい。ストライプ状でもよい。この場合、各ストライプ間での電圧差がほとんど無くなり、輝度のムラを抑制することができる。
【００３０】
○　ストライプ状の補助電極１２を複数本設ける場合、補助電極１２は一定の太さでなくてもよい。接続端子から近い、即ち補助電極を経由して接続端子に至る距離が近い部分では太く、接続端子から遠い、即ち補助電極を経由して接続端子に至る距離が遠い部分では細く形成されてもよい。この場合、接続端子に近い部分では電流値が高く発光が強いが、開口率は低い。一方、接続端子から遠い部分では電流値が低く発光が弱いが、開口率は高い。したがって、全体として輝度ムラを抑制できる。
【００３１】
○　液晶パネルはパッシブ・マトリックス方式でなくてもよい。アクティブ・マトリックス方式など、透過型であればよい。
○　バックライト１０は基板１１と基板１６に挟まれた構成でなくてもよい。例えば図２に示すように、基板１６に代えて水分や酸素の透過を遮断する機能を有する封止膜（パッシベーション膜）１８で有機ＥＬ素子１７を封止してもよい。なお、図２では有機ＥＬ層１４を便宜的に透明電極１３や反射電極１５より厚く図示しているが、実際は有機ＥＬ層１４の方が薄い。
【００３２】
○　面状発光装置は液晶表示装置のバックライトに限らない。たとえば、自動車のルームランプなど、通常の照明装置として利用してもよい。
○　補助電極１２は、透明電極１３の面のうち、有機ＥＬ層１４と反対側の面に設けなくてもよい。例えば、有機ＥＬ層１４側の面に設けてもよい。また、透明電極１３を２層にして補助電極１２をその間に挟んだ構成にしてもよい。
【００３３】
ただし有機ＥＬ層１４側の面に設けた場合、有機ＥＬ層１４は通常蒸着で形成されるため、図３（ａ）に示すように補助電極１２の断面形状が長方形状であると、補助電極１２の側面が有機ＥＬ層１４から露出して反射電極１５と短絡するおそれがある。従って、図３（ｂ）に示すように補助電極１２の断面形状を台形形状にして、有機ＥＬ層１４の蒸着後に、補助電極１２が有機ＥＬ層１４から露出して反射電極１５と短絡しないようにする必要がある。
【００３４】
○　反射電極１５に代えて反射率の低い通常の電極、例えばアルミニウム製の電極を設けてもよい。
○　補助電極１２の格子は一定の大きさでなくてもよい。例えば、透明電極１３を流れる電流量が確保しにくい透明電極１３の接続端子から遠い部分では小さい格子とし、電流量が確保しやすい透明電極１３の接続端子から近い部分では大きい格子としてもよい。
【００３５】
前記実施の形態から把握できる技術的思想（発明）について以下に記載する。
（１）　透明電極を有する面状発光装置において、前記透明電極に、前記透明電極より低抵抗な補助電極を電気的に接続した面状発光装置。
【００３６】
（２）　前記補助電極が格子状に形成されている技術的思想（１）に記載の面状発光装置。
【００３７】
【発明の効果】
以上詳述したように、本発明では、有機ＥＬ素子を用いた面状発光装置において輝度のムラを抑制することができる。
【図面の簡単な説明】
【図１】一実施形態における液晶表示装置の要部概略分解斜視図。
【図２】面状発光装置の別例の積層構造概略図。
【図３】補助電極を透明電極の発光層側に設けた場合の積層構造部分断面図で、（ａ）は補助電極の断面が四角形状の場合、（ｂ）は補助電極の断面が台形形状の場合。
【符号の説明】
１…液晶パネル、１０…バックライト、１２…補助電極、１３…透明電極、１４…発光層としての有機ＥＬ層、１７…有機ＥＬ素子。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a planar light emitting device using an organic EL element.
[0002]
[Prior art]
A conventional light emitting device generates light with heat by using a light bulb, a fluorescent tube, or the like. Further, since the shape is three-dimensional, especially when used for a backlight of a liquid crystal display, it is generally used together with a light guide plate, and it has been difficult to make the liquid crystal display thinner and smaller.
[0003]
On the other hand, in recent technological development, researches on longer life and higher efficiency of the organic EL element have been advanced, and utilization as a planar light emitting device formed in a thin film shape is considered. In a light source device using a light emitting element and a transparent electrode, such as an organic EL element, ITO (indium tin oxide), ZnO (zinc oxide), or the like is mainly used as a transparent electrode.
[0004]
[Problems to be solved by the invention]
However, the electrical resistance of the transparent electrode is not sufficiently low. Therefore, the difference in electric resistance between the portion near and far from the connection terminal increases, and the difference also increases in the current value. Since the light emission luminance of the organic EL element is affected by the current value, unevenness occurs in the light emission luminance.
[0005]
JP-A-8-180974 discloses that an auxiliary electrode is formed on a transparent electrode of an EL display. In this case, the transparent electrode has a stripe shape, and an auxiliary electrode is provided in order to suppress unevenness in light emission luminance generated between a pixel near the connection terminal and a pixel far from the connection terminal.
[0006]
When the organic EL element is used as a planar light emitting device, since the organic EL element is used in a light emitting area larger than that of the stripe-shaped transparent electrode disclosed in Japanese Patent Application Laid-Open No. 8-180974, the electric resistance of the transparent electrode can be reduced. The problem becomes noticeable.
[0007]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a planar light emitting device capable of suppressing uneven brightness.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1, in a planar light emitting device using an organic EL element, an auxiliary electrode having a lower resistance than the transparent electrode is electrically connected to a transparent electrode of the organic EL element. Connected to Therefore, the difference in electric resistance between the portion close to the connection terminal and the portion far from the connection terminal of the transparent electrode is reduced by the auxiliary electrode, and the unevenness in brightness of the entire planar organic EL element can be suppressed.
[0009]
According to a second aspect of the present invention, in the first aspect, the auxiliary electrode is formed in a lattice shape. Therefore, the difference between the electric resistance values is further reduced, and the unevenness in luminance can be further suppressed.
[0010]
According to a third aspect of the present invention, in the first or second aspect, the auxiliary electrode is provided on a surface of the transparent electrode opposite to the light emitting layer (organic EL layer). Have been. Therefore, the auxiliary electrode is not short-circuited in a portion which is not covered with the organic EL layer having a normal thickness of about 100 nm.
[0011]
The invention according to claim 4 is a planar light emitting device using an organic EL element used for a backlight of a transmissive liquid crystal panel, wherein the transparent electrode of the organic EL element has an auxiliary electrode having a lower resistance than the transparent electrode. Are arranged in a lattice in accordance with the pixel pitch of the transmissive liquid crystal panel. Accordingly, unevenness in luminance between pixels of the liquid crystal display can be suppressed in a state where the auxiliary electrodes are not arranged at positions corresponding to the pixels.
[0012]
According to a fifth aspect of the present invention, in the first aspect of the present invention, the auxiliary electrode is formed to be thick at a portion near the connection terminal and thin at a portion far from the connection terminal. . Here, “close to the connection terminal” means that the distance to the connection terminal via the auxiliary electrode is short, and “far from the connection terminal” means the distance to the connection terminal via the auxiliary electrode. Means far away. Therefore, in a portion near the connection terminal, the current value is high and light emission is strong, but the aperture ratio is low. On the other hand, in a portion far from the connection terminal, the current value is low and light emission is weak, but the aperture ratio is high. Therefore, luminance unevenness can be suppressed as a whole.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment in which the present invention is embodied as a backlight of a transmission type liquid crystal display device of a passive matrix system will be described with reference to FIG. In FIG. 1, the upper side is the display unit, which is the front side, and the lower side is the back side.
[0014]
The passive matrix type liquid crystal panel 1 has a polarizing plate 2, a substrate 3, a color filter 4, and a transparent electrode 5 on the front side with a liquid crystal 9 interposed therebetween. In addition, a deflection plate 6, a substrate 7, and a scanning electrode 8 are provided behind the liquid crystal 9 therebetween. And the liquid crystal panel 1 has the liquid crystal 9 in the center part.
[0015]
The deflection plate 2 is formed on the front side of the substrate 3. On the back side, a plurality of stripe-shaped color filters 4 are formed in parallel, and a transparent electrode 5 is formed similarly to the color filters 4. On the other hand, a deflection plate 6 is formed on the back side of the substrate 7. On the front side, a plurality of stripe-shaped scanning electrodes 8 are formed in parallel in a direction perpendicular to the color filters 4 and the transparent electrodes 5. Then, a liquid crystal 9 is provided between the transparent electrode 5 and the scanning electrode 8, and is adhered to each other by a sealing material (not shown) in a state where the distance between the substrates 3 and 7 is kept constant. Therefore, the transparent electrode 5 and the scanning electrode 8 sandwich the liquid crystal 9 and form a pixel at the intersection thereof, and the pixels are arranged in a matrix.
[0016]
The substrates 3 and 7 are both transparent and made of, for example, glass. The transparent electrode 5 and the scanning electrode 8 are both transparent and made of ITO (indium tin compound).
The surface light emitting device as the backlight 10 has substantially the same area as the liquid crystal panel 1 and includes a substrate 11, an auxiliary electrode 12, a transparent electrode 13, an organic EL layer 14, a reflective electrode 15, and a substrate 16. .
[0017]
The substrate 11 is on the front side of the backlight 10 facing the liquid crystal panel 1, on which an auxiliary electrode 12 is formed, and a transparent electrode 13 is formed so as to cover the auxiliary electrode 12. The auxiliary electrode 12 is electrically connected to the transparent electrode 13. The auxiliary electrodes 12 are arranged in a lattice pattern at positions not overlapping with the pixels of the liquid crystal panel 1 in accordance with the pixel pitch. On the other hand, the reflective electrode 15 is formed on the front side of the substrate 16. The organic EL layer 14 is formed between the transparent electrode 13 and the reflection electrode 15. Therefore, the organic EL element 17 includes the transparent electrode 13, the organic EL layer 14, and the reflective electrode 15. The space between the substrate 11 and the substrate 16 is sealed with a sealing material (for example, epoxy resin) (not shown) in order to prevent moisture and oxygen from entering the organic EL layer 14 from the outside.
[0018]
The substrate 11 is transparent, for example, made of glass. The auxiliary electrode 12 has a lower resistance than the transparent electrode 13 and is made of, for example, aluminum. The transparent electrode 13 is made of ITO. The organic EL layer 14 has a known structure, and includes, for example, an electron transport layer, a light emitting layer, and a hole transport layer. Further, the organic EL layer 14 is constituted by a white light emitting layer. The reflection electrode 15 is a metal electrode, for example, made of chromium. The substrate 16 is made of, for example, glass.
[0019]
Next, the operation of the present embodiment configured as described above will be described.
The liquid crystal panel 1 is made to transmit a desired pixel by applying a voltage to the transparent electrode 5 and the scanning electrode 8 by a drive control device (not shown).
[0020]
On the other hand, when the power of the backlight 10 is turned on, it is applied to the transparent electrode 13 and the reflective electrode 15, and the organic EL element emits white light. The emitted light reaches the liquid crystal panel 1 through the transparent electrode 13 and the substrate 11 directly or after being reflected by the reflective electrode 15.
[0021]
Of the light that has reached the liquid crystal panel 1, only light to the pixel portions that have become transmissive comes out to the front side of the liquid crystal panel 1. At this time, the light passes through R (red), G (green), and B (blue) pixels (not shown) of the color filter 4, and a desired color is reproduced by a combination thereof.
[0022]
At this time, although the electrical resistance of the transparent electrode 13 is not sufficiently low, since it is electrically connected to the auxiliary electrode 12, there is almost no voltage difference between a portion near and far from the connection terminal of the transparent electrode 13, resulting in uneven brightness. Can be suppressed.
[0023]
This embodiment has the following effects.
(1) Since the grid-like auxiliary electrode 12 is electrically connected to the transparent electrode 13, there is almost no voltage difference between a portion near and far from the connection terminal of the transparent electrode 13, thereby suppressing uneven brightness. it can.
[0024]
(2) Since the auxiliary electrode 12 is arranged in accordance with the pixel pitch of the liquid crystal panel 1, the auxiliary electrode 12 is not arranged at a position corresponding to the pixel of the liquid crystal panel 1, and the liquid crystal display is It is possible to suppress unevenness in luminance between pixels.
[0025]
(3) The auxiliary electrode 12 is disposed on the surface of the transparent electrode 13 opposite to the organic EL layer 14 which is a light emitting layer. Therefore, even if the cross section of the auxiliary electrode 12 is rectangular, there is no portion that is very thin (usually about 100 nm) that is not covered with the organic EL layer 14, and the auxiliary electrode 12 is short-circuited with the reflective electrode 15. I can't.
[0026]
(4) It can be thinner and smaller than a backlight using a normal cathode tube and a light guide plate.
(5) The reflection electrode 15 is formed on one entire surface of the organic EL layer 14. Therefore, all the light emitted in the direction opposite to the liquid crystal panel 1 is reflected by the reflective electrode 15 and the amount of light emitted to the liquid crystal panel 1 can be increased.
[0027]
The embodiment is not limited to the above, and may be configured as follows, for example.
The grid of the auxiliary electrode 12 may not be provided for each pixel, and may be provided, for example, so as to correspond to a plurality of pixels. Even for each of the plurality of pixels, there is almost no voltage difference between a portion near the connection terminal of the transparent electrode 13 and a portion far from the connection terminal, so that unevenness in luminance can be suppressed.
[0028]
(Circle) the grid of the auxiliary electrode 12 does not need to be every fixed pixel. For example, a portion far from the connection terminal of the transparent electrode 13 where the amount of current flowing through the transparent electrode 13 is difficult to secure may be set for each pixel, and a portion close to the connection terminal of the transparent electrode 13 where the amount of current is easy to secure may be set for a plurality of pixels. .
[0029]
(Circle) the auxiliary electrode 12 does not need to be a lattice shape. It may be striped. In this case, there is almost no voltage difference between the stripes, and uneven brightness can be suppressed.
[0030]
When a plurality of stripe-shaped auxiliary electrodes 12 are provided, the auxiliary electrodes 12 do not need to have a constant thickness. It may be formed thicker at a portion closer to the connection terminal, that is, at a shorter distance to the connection terminal via the auxiliary electrode, and thinner at a portion farther from the connection terminal, ie, at a longer distance to the connection terminal via the auxiliary electrode. . In this case, the current value is high and the light emission is strong in the portion near the connection terminal, but the aperture ratio is low. On the other hand, in a portion far from the connection terminal, the current value is low and light emission is weak, but the aperture ratio is high. Therefore, luminance unevenness can be suppressed as a whole.
[0031]
○ The liquid crystal panel does not have to be a passive matrix type. Any transmission type such as an active matrix type may be used.
The backlight 10 does not have to be configured to be sandwiched between the substrate 11 and the substrate 16. For example, as shown in FIG. 2, instead of the substrate 16, the organic EL element 17 may be sealed with a sealing film (passivation film) 18 having a function of blocking permeation of moisture and oxygen. In FIG. 2, the organic EL layer 14 is shown to be thicker than the transparent electrode 13 and the reflective electrode 15 for convenience, but the organic EL layer 14 is actually thinner.
[0032]
○ The planar light emitting device is not limited to the backlight of the liquid crystal display device. For example, it may be used as a normal lighting device such as a room lamp of a car.
The auxiliary electrode 12 may not be provided on the surface of the transparent electrode 13 opposite to the organic EL layer 14. For example, it may be provided on the surface on the organic EL layer 14 side. Further, the transparent electrode 13 may be formed in two layers, and the auxiliary electrode 12 may be interposed therebetween.
[0033]
However, when provided on the surface on the organic EL layer 14 side, since the organic EL layer 14 is usually formed by vapor deposition, if the auxiliary electrode 12 has a rectangular cross section as shown in FIG. 12 may be exposed from the organic EL layer 14 and short-circuited to the reflective electrode 15. Therefore, as shown in FIG. 3B, the auxiliary electrode 12 is formed to have a trapezoidal cross section so that the auxiliary electrode 12 is not exposed from the organic EL layer 14 and short-circuited with the reflective electrode 15 after the organic EL layer 14 is deposited. Need to be
[0034]
In place of the reflective electrode 15, a normal electrode having a low reflectance, for example, an aluminum electrode may be provided.
(Circle) the grid of the auxiliary electrode 12 does not need to be a fixed size. For example, a small grid may be used in a portion far from the connection terminal of the transparent electrode 13 where the amount of current flowing through the transparent electrode 13 is difficult to secure, and a large grid may be used in a portion close to the connection terminal of the transparent electrode 13 where the amount of current is easy to secure.
[0035]
The technical ideas (inventions) that can be grasped from the above embodiment will be described below.
(1) A planar light emitting device having a transparent electrode, wherein an auxiliary electrode having a lower resistance than the transparent electrode is electrically connected to the transparent electrode.
[0036]
(2) The planar light emitting device according to the technical idea (1), wherein the auxiliary electrode is formed in a lattice shape.
[0037]
【The invention's effect】
As described in detail above, in the present invention, unevenness in luminance can be suppressed in a planar light emitting device using an organic EL element.
[Brief description of the drawings]
FIG. 1 is a schematic exploded perspective view of a main part of a liquid crystal display device according to an embodiment.
FIG. 2 is a schematic view of a laminated structure of another example of the planar light emitting device.
3A and 3B are partial cross-sectional views of a laminated structure in which an auxiliary electrode is provided on a light emitting layer side of a transparent electrode. FIG. 3A shows a case where the cross section of the auxiliary electrode is square, and FIG. in the case of.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Liquid crystal panel, 10 ... Back light, 12 ... Auxiliary electrode, 13 ... Transparent electrode, 14 ... Organic EL layer as a light emitting layer, 17 ... Organic EL element.

Claims (5)

有機ＥＬ素子を用いた面状発光装置において、前記有機ＥＬ素子の透明電極に、前記透明電極より低抵抗な補助電極を電気的に接続した面状発光装置。A planar light emitting device using an organic EL element, wherein an auxiliary electrode having a lower resistance than the transparent electrode is electrically connected to a transparent electrode of the organic EL element. 前記補助電極が格子状に形成された請求項１に記載の面状発光装置。The planar light emitting device according to claim 1, wherein the auxiliary electrode is formed in a lattice shape. 前記補助電極が、前記透明電極の面のうち、発光層と反対側の面に配設された請求項１又は請求項２に記載の面状発光装置。The planar light emitting device according to claim 1, wherein the auxiliary electrode is provided on a surface of the transparent electrode opposite to a light emitting layer. 透過型液晶パネルのバックライトに使用される有機ＥＬ素子を用いた面状発光装置において、前記有機ＥＬ素子の透明電極に、前記透明電極より低抵抗な補助電極を、透過型液晶パネルの画素ピッチに合わせて格子状に配設した面状発光装置。In a planar light emitting device using an organic EL element used for a backlight of a transmissive liquid crystal panel, a transparent electrode of the organic EL element is provided with an auxiliary electrode having a lower resistance than the transparent electrode, and a pixel pitch of the transmissive liquid crystal panel. A planar light-emitting device arranged in a lattice shape in accordance with. 前記補助電極が接続端子から近い部分では太く、接続端子から遠い部分では細く形成されている、請求項１から請求項４のいずれか一項に記載の面状発光装置。The planar light emitting device according to any one of claims 1 to 4, wherein the auxiliary electrode is formed thick at a portion near the connection terminal and thin at a portion far from the connection terminal.
JP2002161542A 2002-06-03 2002-06-03 Planar light emitting device Expired - Fee Related JP3864851B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2002161542A JP3864851B2 (en) 2002-06-03 2002-06-03 Planar light emitting device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2002161542A JP3864851B2 (en) 2002-06-03 2002-06-03 Planar light emitting device

Publications (2)

Publication Number Publication Date
JP2004014128A true JP2004014128A (en) 2004-01-15
JP3864851B2 JP3864851B2 (en) 2007-01-10

Family

ID=30430578

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2002161542A Expired - Fee Related JP3864851B2 (en) 2002-06-03 2002-06-03 Planar light emitting device

Country Status (1)

Country Link
JP (1) JP3864851B2 (en)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006019251A (en) * 2004-06-03 2006-01-19 Semiconductor Energy Lab Co Ltd Lighting system
JP2006100727A (en) * 2004-09-30 2006-04-13 Casio Comput Co Ltd Display panel
US7193362B2 (en) 2003-06-06 2007-03-20 Kabushiki Kaisha Toyota Jidoshokki Planar luminescent device having auxiliary electrode and diffusion mechanism
JP2007227073A (en) * 2006-02-22 2007-09-06 Matsushita Electric Works Ltd Organic electroluminescent panel
WO2008001756A1 (en) * 2006-06-28 2008-01-03 Sumitomo Chemical Company, Limited Organic electroluminescence element
JP2008034362A (en) * 2006-06-28 2008-02-14 Sumitomo Chemical Co Ltd Organic electroluminescent element
WO2008026649A1 (en) 2006-08-30 2008-03-06 Sumitomo Chemical Company, Limited Organic electroluminescence element
CN100410741C (en) * 2004-07-19 2008-08-13 Lg电子有限公司 Liquid crystal display and fabricating method thereof
JP2009224809A (en) * 2004-06-03 2009-10-01 Semiconductor Energy Lab Co Ltd Illuminator
JP2010146821A (en) * 2008-12-18 2010-07-01 Yamagata Promotional Organization For Industrial Technology Organic el panel
KR20120035027A (en) * 2010-10-04 2012-04-13 주성엔지니어링(주) Organic light emitting device and illuminator using the same
WO2012070586A1 (en) * 2010-11-24 2012-05-31 住友化学株式会社 Light emitting device and manufacturing method therefor
WO2012090903A1 (en) 2010-12-28 2012-07-05 Ｎｅｃライティング株式会社 Organic electroluminescent lighting device and method for manufacturing said lighting device
US8592852B2 (en) 2010-05-21 2013-11-26 Semiconductor Energy Laboratory Co., Ltd. Light-emitting device and lighting device
US8659220B2 (en) 2010-06-07 2014-02-25 Nec Lighting, Ltd. Organic electroluminescent lighting device
US8710735B2 (en) 2011-02-22 2014-04-29 Panasonic Corporation Organic electroluminescence element
US8748930B2 (en) 2010-07-26 2014-06-10 Semiconductor Energy Laboratory Co., Ltd. Light-emitting device, lighting device, and manufacturing method of light-emitting device
WO2016006181A1 (en) * 2014-07-11 2016-01-14 パナソニックＩｐマネジメント株式会社 Optical switching device and construction material

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7193362B2 (en) 2003-06-06 2007-03-20 Kabushiki Kaisha Toyota Jidoshokki Planar luminescent device having auxiliary electrode and diffusion mechanism
US9099668B2 (en) 2004-06-03 2015-08-04 Semiconductor Energy Laboratory Co., Ltd. Lighting system
JP2012054251A (en) * 2004-06-03 2012-03-15 Semiconductor Energy Lab Co Ltd Illumination device
US8582058B2 (en) 2004-06-03 2013-11-12 Semiconductor Energy Laboratory Co., Ltd. Lighting system including wiring over electrode
US8847479B2 (en) 2004-06-03 2014-09-30 Semiconductor Energy Laboratory Co., Ltd. Organic electroluminescent lighting system including wiring including a plurality of openings
JP2006019251A (en) * 2004-06-03 2006-01-19 Semiconductor Energy Lab Co Ltd Lighting system
JP4646702B2 (en) * 2004-06-03 2011-03-09 株式会社半導体エネルギー研究所 Illumination device and manufacturing method thereof
JP2009224809A (en) * 2004-06-03 2009-10-01 Semiconductor Energy Lab Co Ltd Illuminator
JP2017191783A (en) * 2004-06-03 2017-10-19 株式会社半導体エネルギー研究所 Illumination device
JP2011091062A (en) * 2004-06-03 2011-05-06 Semiconductor Energy Lab Co Ltd Lighting system
CN100410741C (en) * 2004-07-19 2008-08-13 Lg电子有限公司 Liquid crystal display and fabricating method thereof
JP2006100727A (en) * 2004-09-30 2006-04-13 Casio Comput Co Ltd Display panel
JP2007227073A (en) * 2006-02-22 2007-09-06 Matsushita Electric Works Ltd Organic electroluminescent panel
JP2008034362A (en) * 2006-06-28 2008-02-14 Sumitomo Chemical Co Ltd Organic electroluminescent element
WO2008001756A1 (en) * 2006-06-28 2008-01-03 Sumitomo Chemical Company, Limited Organic electroluminescence element
WO2008026649A1 (en) 2006-08-30 2008-03-06 Sumitomo Chemical Company, Limited Organic electroluminescence element
JP2010146821A (en) * 2008-12-18 2010-07-01 Yamagata Promotional Organization For Industrial Technology Organic el panel
US8592852B2 (en) 2010-05-21 2013-11-26 Semiconductor Energy Laboratory Co., Ltd. Light-emitting device and lighting device
US8659220B2 (en) 2010-06-07 2014-02-25 Nec Lighting, Ltd. Organic electroluminescent lighting device
EP2560462A4 (en) * 2010-06-07 2016-10-26 Nec Lighting Ltd Organic electroluminescent illumination device
US8748930B2 (en) 2010-07-26 2014-06-10 Semiconductor Energy Laboratory Co., Ltd. Light-emitting device, lighting device, and manufacturing method of light-emitting device
US9728737B2 (en) 2010-07-26 2017-08-08 Semiconductor Energy Laboratory Co., Ltd. Light-emitting device, lighting device, and manufacturing method of light-emitting device
KR101707991B1 (en) * 2010-10-04 2017-02-20 주성엔지니어링(주) Organic light emitting device and illuminator using the same
KR20120035027A (en) * 2010-10-04 2012-04-13 주성엔지니어링(주) Organic light emitting device and illuminator using the same
JP2012113917A (en) * 2010-11-24 2012-06-14 Sumitomo Chemical Co Ltd Light-emitting device
WO2012070586A1 (en) * 2010-11-24 2012-05-31 住友化学株式会社 Light emitting device and manufacturing method therefor
WO2012090903A1 (en) 2010-12-28 2012-07-05 Ｎｅｃライティング株式会社 Organic electroluminescent lighting device and method for manufacturing said lighting device
US8969860B2 (en) 2010-12-28 2015-03-03 Nec Lighting, Ltd. Organic electroluminescent lighting device and method for manufacturing the lighting device
US8710735B2 (en) 2011-02-22 2014-04-29 Panasonic Corporation Organic electroluminescence element
WO2016006181A1 (en) * 2014-07-11 2016-01-14 パナソニックＩｐマネジメント株式会社 Optical switching device and construction material
JPWO2016006181A1 (en) * 2014-07-11 2017-04-27 パナソニックＩｐマネジメント株式会社 Optical switching device and building material

Also Published As

Publication number Publication date
JP3864851B2 (en) 2007-01-10

Similar Documents

Publication Publication Date Title
JP3864851B2 (en) Planar light emitting device
US6954239B2 (en) Display unit
JP4951130B2 (en) ORGANIC LIGHT EMITTING DEVICE AND MANUFACTURING METHOD THEREOF
JP4114551B2 (en) Planar light emitting device using auxiliary electrode
JP5477963B2 (en) Transmission type color organic EL display
US7557874B2 (en) Display device
JP4769068B2 (en) ORGANIC LIGHT EMITTING DEVICE AND MANUFACTURING METHOD THEREOF
US7982398B2 (en) Backlight unit and liquid crystal display device including the same
JP4711273B2 (en) Illuminated liquid crystal display device
KR20150039487A (en) Display device
JPH06160850A (en) Liquid crystal display device
JPH10189237A (en) Surface light emitting body and liqiud crystal display device using it
KR100702879B1 (en) Lighting device and display device incorporating the same
JP2004047194A (en) Color display device
US10094534B2 (en) Surface-emitting unit having dimming regions
US20160312964A1 (en) Surface Emitting Unit
JP4591244B2 (en) Display device
JP4990587B2 (en) Light emitting device and manufacturing method thereof
JP2004087439A (en) Lighting system and liquid crystal display device
KR20060047227A (en) Organic light multi-face emitting diode with multi-layer and that manufacturing method
KR20070065094A (en) Oled display panel
JP2003223993A (en) El color display device
JP3982259B2 (en) Reflective multilayer liquid crystal display
JP2008077880A (en) Organic light-emitting diode element
JP3879356B2 (en) Organic electroluminescence light source

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20040119

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20060530

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20060728

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20060912

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20060925

LAPS Cancellation because of no payment of annual fees