JP2004107451A - Phosphor and fluorescent display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a new red to yellow light-emitting phosphor applicable to a VFD (Vacuum Fluorescent Display) as a substitute for a conventional sulfide phosphor. <P>SOLUTION: The phosphor substantially comprises a compound oxide represented by the general formula: A<SB>x</SB>B<SB>y</SB>Sr<SB>1-x-y</SB>ZnO<SB>2</SB>(A and B are each mutually different elements selected from the group consisting of Mg, Ca and Ba and x and y are each a number satisfying 0≤x≤1, 0≤y≤1 and 0≤x+y≤1) and a metal element (activator) constituting the luminescence center doped with the compound oxide. The preferable activator is Mn. <P>COPYRIGHT: (C)2004,JPO

Description

【００３３】
次に、比較例１〜５として従来のＭｎ付活酸化物蛍光体を製造し、上記と同様に発光スペクトルを調べ、その発光ピーク位置（波長）を調べた。
すなわち、原料物質及び混合モル比を適宜選定しつつ上記製造例と同様の手順によって、母体物質がＺｎＧａ_２Ｏ_４、ＺｎＡｌ_２Ｏ_４、Ｚｎ_２ＳｉＯ_４、Ｚｎ_２ＧｅＯ_４またはＭｇＧａ_２Ｏ_４であり、付活剤がＭｎである計５種類の酸化物蛍光体（但し母体物質に対する付活剤濃度（モル百分率）はいずれも１ｍｏｌ％とした）を作製した。次いで、各比較例に係る蛍光体について、波長２８３ｎｍの紫外線で励起したときの発光スペクトルを調べた。表２に、各比較例の発光スペクトルにおけるピーク位置（波長）を実施例２のピーク位置とともに示す。
表２から明らかなように、上記５種類の母体物質にＭｎをドープして成る従来の酸化物蛍光体（比較例１〜５）は、いずれも発光ピーク波長が５００〜５４０ｎｍの範囲内にあり、本発明に係る蛍光体の発光ピーク波長域と明確に異なっていた。
【００３４】
【表２】

【００３５】
＜蛍光体の発光性能評価＞
次に、実施例１〜８に係る蛍光体の発光性能を評価するため、各実施例に係る蛍光体の発光ピーク波長における輝度（発光強度）の比較を行った。その結果、実施例２の蛍光体（Ｍｎ濃度：１ｍｏｌ％）が最も高い輝度を示した。図３は、かかる実施例２の蛍光体の輝度（発光強度）を１としたときの各実施例に係る蛍光体の相対輝度（相対強度）を示したグラフである。図中の横軸の数値はＭｎ^２＋濃度（ｘ）であり、縦軸は相対強度（Ｎｏｒｍａｌｉｚｅｄ　ｉｎｔｅｎｓｉｔｙ）を示す。
このグラフから明らかなように、Ｍｎ濃度１ｍｏｌ％の蛍光体（実施例２）を中心にＭｎ濃度が０．５ｍｏｌ％〜３ｍｏｌ％の蛍光体（実施例１〜実施例４）はいずれも高い輝度（図示されるように相対強度０．５以上）を実現する蛍光体であった。なかでも実施例１〜３の蛍光体は特に高い輝度（図示されるように相対強度０．７以上）を実現した。
図示されるように、付活剤濃度が母体物質に対して０．２〜３ｍｏｌ％（特に好ましくは０．４〜２ｍｏｌ％）となるように付活剤（ここではＭｎ）をドープした本発明に係る蛍光体は、紫外線励起の発光スペクトルにおいて市販のＺｎＳ：Ｃｕ，Ａｌ蛍光体の約８０％のピーク強度を持つ。このことから実用性に優れる黄色発光用蛍光体であることが確かめられた。
【００３６】
同様に、実施例１０〜１２に係る蛍光体の発光性能を評価するため、各実施例に係る蛍光体の発光ピーク波長における輝度（発光強度）の比較を行った。その結果、実施例１０の蛍光体（Ｔｂ濃度：１ｍｏｌ％）が最も高い輝度を示した。図１３は、かかる実施例１０の蛍光体の輝度（発光強度）を１としたときの各実施例に係る蛍光体の相対輝度（相対強度）を示したグラフである。図中の横軸の数値はＴｂ濃度（ｘ）であり、縦軸は相対強度（Ｒｅｌａｔｉｖｅ　ｉｎｔｅｎｓｉｔｙ）を示す。このグラフから明らかなように、Ｔｂ濃度１ｍｏｌ％の蛍光体（実施例１０）を最高にＴｂ濃度１ｍｏｌ％〜５ｍｏｌ％の蛍光体（実施例１０〜実施例１２）はいずれも高い輝度（図示されるように相対強度０．６以上）を実現する蛍光体であった。
【００３７】
また、実施例１３〜１５に係る蛍光体の発光性能を評価するため、各実施例に係る蛍光体の発光ピーク波長における輝度（発光強度）の比較を行った。その結果、実施例１３の蛍光体（Ｐｒ濃度：１ｍｏｌ％）が最も高い輝度を示した。図１４は、かかる実施例１３の蛍光体の輝度（発光強度）を１としたときの各実施例に係る蛍光体の相対輝度（相対強度）を示したグラフである。図中の横軸の数値はＰｒ濃度（ｘ）であり、縦軸は相対強度（Ｒｅｌａｔｉｖｅ　ｉｎｔｅｎｓｉｔｙ）を示す。
このグラフから明らかなように、Ｐｒ濃度１ｍｏｌ％の蛍光体（実施例１３）を最高にＰｒ濃度１ｍｏｌ％〜５ｍｏｌ％の蛍光体（実施例１３〜実施例１５）はいずれも高い輝度（図示されるように相対強度０．８以上）を実現する蛍光体であった。
【００３８】
＜蛍光表示管の製造例＞
次に、上記製造例で得られた蛍光体（例えば実施例１〜４）をＶＦＤに適用した一例について説明する。なお、図４は本実施例に係る蛍光表示管１０の一部を切り欠いて示す斜視図である。
本蛍光表示管１０は、所定の発光パターンに形成された蛍光素子たる蛍光体層２０Ｓ，２０Ｄ，２０Ｎを複数箇所に備えたガラス、セラミックス、琺瑯などの絶緑性材料製の基板１２と、枠状に形成されたガラス製のスペーサ１４と、透明なカバー・ガラス板１６と、複数本の陽極端子１８Ｐ、複数本のグリッド端子１８Ｇ、カソード１８Ｋ、および補助グリッド端子１８ＳＧとを備えている。
而して、それら基板１２、スペーサ１４、およびカバー・ガラス板１６が相互にガラス封着されることにより気密容器が構成され、その内部にそれらの部材により囲まれた真空空間が形成されている。
【００３９】
上記基板１２の真空空間により覆われた蛍光表示管１０の表示面１９には、セグメントで「８」文字形状を表す複数個の蛍光体層２０Ｓ、ドット形状を表す１個の蛍光体層２０Ｄ、「１」文字形状を菱す１個の蛍光体層２０Ｎ等が配置されている。それら各蛍光体層２０Ｓ，２０Ｄ，２０Ｎは、グリッド電極２２および補助グリッド電極２４によりそれぞれ囲まれている。
そして、上記各蛍光体層２０Ｓ，２０Ｄ，２０Ｎのうちの各表示桁毎にあらかじめ定められた位置のものは、後述する陽極用プリント配線３４（図６）を介して各陽極端子１８Ｐにそれぞれ接続されている。また、上記各グリッド電極２２はグリッド配線２６を介して各グリッド端子１８Ｇにそれぞれ接続され、各補助グリッド電極２４は補助グリッド配線２８を介して各補助グリッド端子１８ＳＧに接続されている。
【００４０】
また、上記基板１２の両端部には、上記カソード端子１８Ｋを備えた一対のフィラメント支持フレーム３０（図４では右側に位置する一方だけを示す。）がそれぞれ固設されており、それらフィラメント支持フレーム３０の間には、直熱型カソード（陰極）として機能する細線状の複数本のフィラメント（フィラメント・カソード）３２が基板１２の長手方向に平行であって基板１２の表示面１９から離隔した所定の高さ位置となるように張設されている。
このフィラメント３２は、例えば、表面に電子放出層として（Ｂａ、Ｓｒ、Ｃａ）Ｏ等のような比較的仕事関数の低いアルカリ土類金属の酸化物固溶体がコーティングされたタングステン・ワイヤ等からなるものである。
【００４１】
図５およびそのＶＩ−ＶＩ線断面図である図６は、上記表示面１９に備えられた表示パターンの１つである「８」文字形状の蛍光体層２０Ｓ近傍の構成およびその断面構造を示す図である。
これら図面に示すように、基板１２の表示面１９には、陽極端子１８Ｐに接続される陽極用プリント配線３４が厚膜スクリーン印刷法や蒸着法等によって形成されている。その上には、所定の厚みに形成され且つ厚み方向に貫通するスルーホール３６を適宜備えた絶縁体層３８が固着されている。この絶縁体層３８は、厚膜スクリーン印刷法等によって形成されたものであり、低融点ガラスおよび着色顔料で構成されている。
【００４２】
また、上記絶縁体層３８の上には、蛍光体層２０Ｓと同様であるが若干大きいパターン形状のグラファイト層４０が上記スルーホール３６を介して陽極用印刷配線３４と導通する位置に形成されている。このグラファイト層４０は表示管１０の陽極として機能するものである。本実施例においてかかる蛍光体層２０Ｓ，２０Ｄ，２０Ｎは、このグラファイト層４０の上に厚膜蛍光体ぺ一ストを印刷して形成されたものであり、当該グラファイト層４０を介して加速電圧が印加されるように構成されている。
なお、かかる蛍光体層２０Ｓ，２０Ｄ，２０Ｎには、Ｒ（赤）、Ｙ（黄）等の発光色を有する本発明の蛍光体が適宜選択されて用いられる。すなわち、上記蛍光体層２０Ｓ，２０Ｄ，２０Ｎは、グラファイト層４０の上に本発明の蛍光体からなるペーストが厚膜状に印刷されることによって形成され得る。
【００４３】
一方、蛍光体層２０Ｓの周囲には、その外周縁に接触し旦つ取り囲んだ状態のリブ状壁４４がグラファイト層４０の上からフィラメント３２に向かう方向へ立設されている。さらにリブ状壁４４は、絶緑体層３８上に立設された補助リブ状壁４６によって取り囲まれている。これらリブ状壁４４および補助リブ状壁４６は、低融点ガラスおよびアルミナ等の無機フィラー等からなるものであり、互いに同様な高さ寸法を有して何れもその上端が蛍光体層２０Ｓよりも上側に位置する。
【００４４】
上記グリッド電極２２および補助グリッド電極２４は、粒子状のグラファイト、銀、パラジウム、銅、アルミニウム、ニッケル等の粒子状導電性物質を主成分とする厚膜導体であって、厚膜スクリーン印刷法によってこれらリブ状壁４４および補助リブ状壁４６の頂部に所定の厚さで設けられている。また、グリッド電極２２および補助グリッド電極２４は、絶縁体層３８の上に形成されたグリッド配線２６、補助グリッド配線２８、およびそれらに連続して形成されたグリッド・パッド４８、補助グリッド・パッド５０を介して上記グリッド端子１８Ｇ、補助グリッド端子１８ＳＧにそれぞれ接続されている。
【００４５】
図４に示すように、蛍光表示管１０の左端部すなわち長手方向における一方の端部には、円筒状のガラスからなる排気管５２が備えられている。この排気管５２は、蛍光表示管１０の製造工程において、上述の基板１２、スペーサ１４、およびカバー・ガラス板１６をガラス封着して気密容器が構成された後に、その内部から排気して真空にする目的で設けられたものであり、その先端部は排気終了後にガス・バーナー等によって溶断されている。
【００４６】
以上のように構成された蛍光表示管１０を駆動するに際しては、フィラメント３２に所定のヒート電流を定常的に流した状態で各グリッド電極２２に順次加速電圧を印加し、それに同期して複数の蛍光体層２０Ｓ，２０Ｄ，２０Ｎのうち発光させるべき何れかのものに加速電圧をグラファイト層４０を介して印加する。このことによって、フィラメント３２から放出された熱電子は加速電圧を印加されたグリッド電極２２によって加速される。而して、それに囲まれた蛍光体層２０Ｓ，２０Ｄ，２０Ｎにも加速電圧力が印加されると、その熱電子が衝突して蛍光体層２０Ｓ，２０Ｄ，２０Ｎが発光する。ここで、グリッド電極２２は熱電子の蛍光体層２０Ｓ，２０Ｄ，２０Ｎへの到達を制御する制御電極であり、補助グリッド電極２４は周囲のグリッド電極２２によって形成される負電界の影響を排除して、その蛍光体層２０Ｓ，２０Ｄ，２０Ｎへ一様に熱電子を向かわせるためのものである。なお、かかる駆動方法の詳細は、本発明の蛍光体を理解するうえで特に必要がなく、当業者における周知・常識事項であるので省略する。
【００４７】
そして，本実施例においては、上記蛍光体層２０Ｓ，２０Ｄ，２０Ｎに上述の各実施例において製造されるような本発明の蛍光体をいくつか適用した。すなわち、本実施例においては、上記グラファイト層４０上に、以下に示す本発明の蛍光体と適当なビヒクルを主成分として含むペースト（ペースト調製方法や用いるビヒクル等の材料選択は従来と同様でよく特に限定されない。）を厚膜状に印刷することによって上記蛍光体層２０Ｓ，２０Ｄ，２０Ｎを形成した。
本実施例においては、実施例２すなわちＳｒＺｎ_０．９９Ｍｎ_０．０１Ｏ_２で示される蛍光体を、上記蛍光体層２０Ｓ，２０Ｄ，２０Ｎに採用した。その結果、照射された低速電子線（例えば３０Ｖ）によって、高輝度の黄色発光が実現できた。また、目立ったチャージアップ現象も認められなかった。
【００４８】
以上、本発明の具体例を詳細に説明したが、これらは例示にすぎず、特許請求の範囲を限定するものではない。特許請求の範囲に記載の技術には、以上に例示した具体例を様々に変形、変更したものが含まれる。
また、本明細書または図面に説明した技術要素は、単独であるいは各種の組み合わせによって技術的有用性を発揮するものであり、出願時請求項記載の組み合わせに限定されるものではない。また、本明細書または図面に例示した技術は複数目的を同時に達成するものであり、そのうちの一つの目的を達成すること自体で技術的有用性を持つものである。
【図面の簡単な説明】
【図１】一実施例に係る蛍光体の粉末Ｘ線回折図形（ＸＲＤパターン）を示すグラフである。
【図２】いくつかの実施例に係る蛍光体の紫外線励起による発光スペクトルを示すグラフである。
【図３】本発明の蛍光体におけるＭｎ濃度と発光強度との関係を示すグラフである。
【図４】一実施例における蛍光表示管の一部破断の斜視図である。
【図５】図４における蛍光体層近傍を示す部分平面図である。
【図６】図５におけるＶＩ−ＶＩ線断面図である。
【図７】一実施例に係る蛍光体の粉末Ｘ線回折図形（ＸＲＤパターン）を示すグラフである。
【図８】一実施例に係る蛍光体の粉末Ｘ線回折図形（ＸＲＤパターン）を示すグラフである。
【図９】一実施例に係る蛍光体の粉末Ｘ線回折図形（ＸＲＤパターン）を示すグラフである。
【図１０】一実施例に係る蛍光体の紫外線励起による発光スペクトルを示すグラフである。
【図１１】一実施例に係る蛍光体の紫外線励起による発光スペクトルを示すグラフである。
【図１２】一実施例に係る蛍光体の紫外線励起による発光スペクトルを示すグラフである。
【図１３】本発明の蛍光体におけるＴｂ濃度と発光強度との関係を示すグラフである。
【図１４】本発明の蛍光体におけるＰｒ濃度と発光強度との関係を示すグラフである。
【符号の説明】
１０　蛍光表示管
２０Ｓ，２０Ｄ，２０Ｎ　蛍光体層[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxide phosphor containing an oxide containing an alkaline earth metal element as a base material (matrix), and more particularly to a phosphor capable of emitting light by irradiation with a low electron beam and such a phosphor. The present invention relates to a fluorescent display device provided with a phosphor.
[0002]
2. Description of the Related Art Phosphors that emit light when irradiated with an electron beam at a low voltage (low speed) of 1 kV or less are fluorescent display devices such as a vacuum display tube (VFD) and a field emission display (FED). Are used as light emission sources (that is, fluorescent elements) in the above. For example, as a blue to green light-emitting phosphor, ZnGa ₂ O ₄ : Mn (that is, the activator is Mn and the host substance is ZnGa ₂ O ₄ It is. Hereinafter, the description will be similarly made. ), ZnO: Zn and the like are used (JP-A-6-340875, JP-A-9-194834). Other green light-emitting phosphors include Zn ₂ GeO ₄ : Mn (JP-A-2000-87032).
[0003]
On the other hand, as a red to yellow light emitting phosphor, a sulfide phosphor such as (Zn, Cd) S: Cu, Al, etc. (Japanese Patent Laid-Open No. 5-65479) can be mentioned. Other red light-emitting phosphors include Ba _0.92 Eu _0.08 Zn _1.08 Ga _9.92 O ₁₇ Oxide phosphors containing a rare earth element such as (JP-A-2001-81459).
[0004]
[Patent Document 1] JP-A-5-65479
[Patent Document 2] JP-A-6-340875
[Patent Document 3] JP-A-9-194834
[Patent Document 4] JP-A-2000-87032
[Patent Document 5] JP-A-2001-81459
[0005]
The sulfide phosphor (ZnCdS-based phosphor) used as the above-mentioned red or yellow light-emitting phosphor is decomposed from the parent substance by electron beam collision or the like when used for VFD. -The separated sulfur component may adhere to the surface of the cathode (cathode) and deteriorate the electron emission characteristics. The deterioration of the electron emission characteristics is not preferable because the luminance of the phosphor decreases and the life of the VFD is shortened. Also, conventional sulfide phosphors contain cadmium, but the use of phosphors containing environmentally unfavorable elements such as cadmium has been refrained due to increasing environmental concerns.
Therefore, an object of the present invention is to provide a new red-to-yellow light-emitting phosphor (particularly, a yellow light-emitting phosphor) applicable to VFD and the like as a substitute for a sulfide phosphor.
[0006]
The red to yellow light-emitting phosphor provided by the present invention uses an electron beam of a low voltage of 1 kV or less (for example, 5 V to 50 V, typically 12 V to 40 V). An oxide phosphor that is excited to emit red or yellow light.
Note that, in this specification, a phosphor that emits red or yellow light refers to a phosphor in which light emitted from the phosphor can be visually recognized as red to yellow (including greenish yellow-green) as a whole. It is not limited to a phosphor having an emission peak only in a yellow wavelength range (for example, 550 to 600 nm). For example, a phosphor that has emission peaks at around 500 nm and around 600 nm and whose emission color (fluorescence color) is visually recognized as yellow as a whole is a phosphor that is included in the red to yellow emission phosphors in this specification. It is.
The phosphor provided by the present invention has the general formula: A _x B _y Sr _1-xy ZnO ₂ And a metal element (activator) constituting a luminescence center doped in the composite oxide. Here, A and B in the formula are respectively different elements selected from the group consisting of Mg, Ca and Ba, and x and y are 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ x + y ≦ 1. It is the number to satisfy.
[0007]
The above-mentioned oxide phosphor does not contain sulfur as a host substance and an activator, and does not include components that are provided in a fluorescent display device such as a VFD and that can deteriorate the cathode when irradiated with an electron beam. For this reason, according to the phosphor of the present invention, it is possible to suppress cathode deterioration (deterioration of electron emission characteristics) of the fluorescent display device and prevent a decrease in luminance of the phosphor. Further, the life of the fluorescent display device can be extended. Further, it does not contain cadmium, and is preferable from the viewpoint of environmental conservation.
[0008]
A preferred phosphor of the present invention contains Mn as a metal element (ie, an activator) constituting the emission center. For example, the general formula: A _x B _y Sr _1-xy Zn _1-z Mn _z O ₂ Are preferred. Here, A and B in the formula are respectively different elements selected from the group consisting of Mg, Ca and Ba, and x and y are 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ x + y ≦ 1. Z is a number that preferably satisfies 0.001 ≦ z ≦ 0.05.
In the phosphor having this configuration, Mn becomes the emission center, so that the emission luminance can be further increased.
[0009]
According to another aspect of the present invention, there is provided a VFD or other fluorescent display device including the phosphor. That is, the fluorescent display device of the present invention includes a substrate, an electrode, and a phosphor (fluorescent element), and at least a part of the phosphor is formed of the phosphor of the present invention.
According to the fluorescent display device having this configuration, red to yellow (typically yellow) light emission can be realized without using a conventional sulfide phosphor.
[0010]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.
[0011]
The phosphor of the present invention has a general formula: A _x B _y Sr _1-xy ZnO ₂ Wherein A and B in the formula are different elements selected from the group consisting of Mg, Ca and Ba, and x and y satisfy 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ x + y ≦ 1 The complex oxide represented by the formula (1) is used as a matrix (matrix), and the complex oxide has a structure in which the metal element (activator) constituting the emission center is doped. It is not limited to such compounds.
As the alkaline earth metal element contained in the base, strontium is preferable, and a composition having a high content of such an element is preferable. Those satisfying the condition of 0 ≦ x + y ≦ 0.2 in the above general formula are preferable. In the case where an alkaline earth metal element other than strontium is contained, it is preferable that only one element selected from the group consisting of magnesium, calcium and barium is contained. For example, A _x Sr _1-x ZnO ₂ (A in the formula is selected from the group consisting of Mg, Ca and Ba, and x is a number satisfying 0 ≦ x ≦ 0.2). Mg is suitable as A in the above formula.
Among the phosphors disclosed herein, one particularly preferred embodiment is a phosphor in which both x and y in the above general formula are 0, that is, SrZnO. ₂ And a structure in which the oxide is doped with a metal element constituting a luminescence center.
[0012]
Mn, Al, Ag, Cu, Cl and the like can be mentioned as a metal element (activator) constituting the luminescence center, and a preferable metal element is Mn.
General formula: A _x B _y Sr _1-xy Zn _1-z Mn _z O ₂ Wherein A and B in the formula are different elements selected from the group consisting of Mg, Ca and Ba, and x and y satisfy 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ x + y ≦ 1 Is a number, and z is a number satisfying 0.001 ≦ z ≦ 0.05).
A phosphor in which x and y in the above general formula are both 0, that is, SrZn containing only strontium as an alkaline earth metal element _1-z Mn _z O ₂ (Where z in the formula is a number that satisfies 0.001 ≦ z ≦ 0.05) is particularly preferable.
[0013]
Alternatively, a rare earth element may be mentioned as another suitable metal element constituting the emission center. In particular, terbium (Tb) and praseodymium (Pr) are preferable.
General formula: A _x B _y Sr _{1-xy- (3/2) z} RE _z ZnO ₂ (A and B in the formula are mutually different elements selected from the group consisting of Mg, Ca and Ba, and x and y are 0 ≦ x ≦ 1- (3/2) z and 0 ≦ y ≦ 1- (3/2) z and a number satisfying 0 ≦ x + y ≦ 1− (3/2) z, z is a number satisfying 0.001 ≦ z ≦ 0.05, and RE is one or more rare earth elements. A phosphor represented by an element (typically, Tb or Pr) is preferable. Those in which z satisfies 0.005 ≦ z ≦ 0.05 are more preferable.
A phosphor in which x and y are both 0 in the above general formula, that is, Sr containing only strontium as an alkaline earth metal element _{1- (3/2) z} RE _z ZnO ₂ (Where z is a number satisfying 0.001 ≦ z ≦ 0.05, and RE is one or more rare earth elements (typically Tb or Pr)). . Those in which z satisfies 0.005 ≦ z ≦ 0.05 are more preferable.
[0014]
The present invention seeks to provide a red-to-yellow phosphor, particularly a phosphor that emits yellow light (approximately having a peak in a wavelength range of 575 to 585 nm). It is preferable that the concentration (molar percentage) of Mn) be 3 mol% or less. For example, in the above general formula using Mn as an activator, z in the formula is preferably 0.001 ≦ z ≦ 0.03.
[0015]
Further, from the viewpoint of providing a phosphor realizing a practically preferable high emission luminance, the concentration (mole percentage) of the activator (typically Mn) with respect to the base substance is about 0.2 to 5 mol%. It is particularly preferable that the content is about 0.4 to 2 mol%. For example, in the above general formula using Mn as an activator, z in the formula is preferably 0.002 ≦ z ≦ 0.03, and particularly preferably 0.004 ≦ z ≦ 0.02. More preferably, 0.005 ≦ z ≦ 0.015.
[0016]
Next, a method for producing the phosphor of the present invention will be described. The phosphor of the present invention can be produced by mixing and firing various compounds (starting materials) under high-temperature conditions, similarly to the conventional phosphor production.
Such a starting material may be an oxide that is decomposed during firing to be an oxide, and does not necessarily need to be an oxide at the raw material stage. Therefore, various hydroxides, carbonates, nitrates, organic acid salts, and the like can be used as starting materials in addition to the original oxides. These are mixed so as to have a predetermined ratio (molar ratio), and are mixed in the air, preferably in an inert atmosphere or in a reducing atmosphere (for example, in an inert gas such as argon, preferably such an inert gas). The phosphor of the present invention can be obtained by firing in a predetermined temperature range in a reducing atmosphere such as a gas (Ar or the like) mixed with a reducing gas such as a hydrogen gas at about 5 to 10 vol%).
[0017]
For example, SrZn _1-z Mn _z O ₂ When producing (synthesizing) a phosphor represented by the formula (z is a number satisfying 0.001 ≦ z ≦ 0.05), a strontium compound (for example, carbonate) is used as a raw material (preferably a powdery substance). Strontium), a zinc compound (for example, zinc oxide), and a manganese compound (for example, manganese carbonate) are mixed at a molar ratio of 1: 1-z: z. Such mixing may be performed in a dry manner by placing each raw material in a predetermined vessel (for example, an agate mortar) or may be performed by a wet method (for example, mixing by adding acetone in an agate mortar).
Next, the mixed sample is placed in a suitable heat-resistant container for firing, such as an alumina crucible, and fired at a high temperature of preferably 900 ° C. to 1300 ° C. for 1 to 12 hours (preferably 3 to 10 hours). Although not particularly limited, the rate of temperature rise from room temperature to the maximum firing temperature is preferably about 100 to 200 ° C. per hour. After completion of the firing, the product is cooled in a furnace to obtain a typically powdery product.
When a phosphor having a predetermined shape is to be obtained, the sample after mixing is molded into a predetermined shape by various molding means, and then the molded sample (for example, a pellet formed by uniaxial molding). May be fired as described above. Further, when the molded sample is fired, the contact area between the raw material powders is larger than when the powder itself is fired, so that the sintering reaction can be promoted.
[0018]
The powdery phosphor obtained by the above-described firing procedure or the like can be subjected to various secondary processings in accordance with the application form, similarly to conventional ceramics. For example, when it is used as a fluorescent element of a fluorescent display tube (see FIG. 4) as shown in an embodiment to be described later, it is preferable to process the powdery fluorescent substance into a thin film or plate suitable for the mounting shape. For example, by processing the phosphor of the present invention into a paste using an appropriate vehicle containing an organic binder, applying the paste on a glass substrate on which an anode electrode is formed by screen printing, and further removing the organic binder by firing. Thus, an anode substrate coated with the phosphor of the present invention can be prepared.
The phosphor of the present invention can be processed into various forms by performing such secondary processing. As a result, the phosphor for red to yellow emission in VFDs, FEDs, CRTs, and the like in which conventional phosphors are used. It can be used as a fluorescent element. The processing method, processing means, and the like to be employed may be the same as those for processing a conventional phosphor, and do not particularly characterize the present invention, and thus will not be described in detail.
[0019]
The present invention will be described in more detail with reference to the following examples, but it is not intended to limit the present invention to those shown in the examples.
[0020]
<Production example of phosphor>
SrCO in powder form ₃ , ZnO and MnCO ₃ Were mixed at a molar ratio of 1: 0.995: 0.005. That is, these raw material powders were weighed so as to have the above molar ratio, and were dry-mixed using an agate mortar. Thereafter, the mixed powder material was uniaxially molded at a pressure of 50 MPa to form a pellet having a diameter of 10 mm and a height of 3 mm. This was put in an alumina crucible and fired at 1000 ° C. for 5 hours in an atmosphere of 95 vol% of argon and 5 vol% of hydrogen gas.
Next, the calcined material was put in an agate mortar, pulverized, and sieved with a # 305 polyester fiber mesh to remove SrZn from which coarse particles having a particle size of about 20 μm or more were removed. _0.995 Mn _0.005 O ₂ A powdered inorganic compound (Example 1) corresponding to (Mn concentration: 0.5 mol%) was obtained.
[0021]
SrCO ₃ , ZnO and MnCO ₃ Were mixed in a molar ratio of 1: 0.99: 0.01 by the same process as in the production of the powdery inorganic compound according to Example 1 to obtain SrZn. _0.99 Mn _0.01 O ₂ A powdered inorganic compound (Example 2) corresponding to (Mn concentration: 1 mol%) was obtained.
Similarly, by changing the molar ratio of each raw material (that is, the doping amount of Mn), _0.98 Mn _0.02 O ₂ (Mn concentration: 2 mol%), powdery inorganic compound (Example 3), SrZn _0.97 Mn _0.03 O ₂ (Mn concentration: 3 mol%), a powdery inorganic compound (Example 4), SrZn _0.95 Mn _0.05 O ₂ (Mn concentration: 5 mol%), powdery inorganic compound (Example 5), SrZn _0.93 Mn _0.07 O ₂ (Mn concentration: 7 mol%) Powdered inorganic compound (Example 6) corresponding to SrZn _0.91 Mn _0.09 O ₂ (Mn concentration: 9 mol%), a powdery inorganic compound (Example 7), and SrZn _0.8 Mn _0.2 O ₂ A powdered inorganic compound (Example 8) corresponding to (Mn concentration: 20 mol%) was obtained.
[0022]
SrCO in powder form ₃ , BaCO ₃ , ZnO and MnCO ₃ Were mixed at a molar ratio of 0.9: 0.1: 0.99: 0.01. That is, these raw material powders were weighed so as to have the above molar ratio, and were dry-mixed using an agate mortar. Then, Sr from which coarse particles having a particle size of about 20 μm or more were removed by the same process as in the production of the powdery inorganic compound according to Example 1. _0.9 Ba _0.1 Zn _0.99 Mn _0.01 O ₂ A powdered inorganic compound (Example 9) represented by the composition formula (Mn concentration: 1 mol%) was obtained.
[0023]
SrCO of the raw material powder so that Sr: Tb: Zn = 0.85: 0.01: 1 (molar ratio) ₃ , Tb ₄ O ₇ And ZnO were weighed and dry mixed using an agate mortar. Then, Sr from which coarse particles having a particle size of about 20 μm or more were removed by the same process as in the production of the powdery inorganic compound according to Example 1. _0.985 Tb _0.01 ZnO ₂ A powdered inorganic compound (Example 10) corresponding to (Tb concentration: 1 mol%) was obtained.
[0024]
SrCO of the raw material powder so that Sr: Tb: Zn = 0.955: 0.03: 1 (molar ratio) ₃ , Tb ₄ O ₇ And ZnO were weighed and dry mixed using an agate mortar. Then, Sr from which coarse particles having a particle size of about 20 μm or more were removed by the same process as in the production of the powdery inorganic compound according to Example 1. _0.955 Tb _0.03 ZnO ₂ A powdered inorganic compound (Example 11) corresponding to (Tb concentration: 3 mol%) was obtained.
[0025]
SrCO of the raw material powder so that Sr: Tb: Zn = 0.925: 0.05: 1 (molar ratio) ₃ , Tb ₄ O ₇ And ZnO were weighed and dry mixed using an agate mortar. Then, Sr from which coarse particles having a particle size of about 20 μm or more were removed by the same process as in the production of the powdery inorganic compound according to Example 1. _0.925 Tb _0.05 ZnO ₂ A powdered inorganic compound (Example 12) corresponding to (Tb concentration: 5 mol%) was obtained.
[0026]
SrCO of the raw material powder so that Sr: Pr: Zn = 0.985: 0.01: 1 (molar ratio) ₃ , Pr ₆ O ₁₁ And ZnO were weighed and dry mixed using an agate mortar. Then, Sr from which coarse particles having a particle size of about 20 μm or more were removed by the same process as in the production of the powdery inorganic compound according to Example 1. _0.985 Pr _0.01 ZnO ₂ A powdered inorganic compound (Example 13) corresponding to (Pr concentration: 1 mol%) was obtained.
[0027]
SrCO of the raw material powder so that Sr: Pr: Zn = 0.955: 0.03: 1 (molar ratio) ₃ , Pr ₆ O ₁₁ And ZnO were weighed and dry mixed using an agate mortar. Then, Sr from which coarse particles having a particle size of about 20 μm or more were removed by the same process as in the production of the powdery inorganic compound according to Example 1. _0.955 Pr _0.03 ZnO ₂ A powdered inorganic compound (Example 14) corresponding to (Pr concentration: 3 mol%) was obtained.
[0028]
SrCO of the raw material powder so that Sr: Pr: Zn = 0.925: 0.05: 1 (molar ratio) ₃ , Pr ₆ O ₁₁ And ZnO were weighed and dry mixed using an agate mortar. Then, Sr from which coarse particles having a particle size of about 20 μm or more were removed by the same process as in the production of the powdery inorganic compound according to Example 1. _0.925 Pr _0.05 ZnO ₂ A powdered inorganic compound (Example 15) corresponding to (Pr concentration: 5 mol%) was obtained.
[0029]
From the results of powder X-ray diffraction of the obtained compounds (phosphors) according to the respective examples, it was clear that all of the obtained inorganic compounds were single-phase pure products without any by-products. became. As an example, FIG. 1 shows a compound SrZn according to Example 2. _0.99 Mn _0.01 O ₂ FIG. 7 shows a powder X-ray diffraction pattern (XRD pattern) of the compound Sr according to Example 9. _0.9 Ba _0.1 Zn _0.99 Mn _0.01 O ₂ FIG. 8 shows a powder X-ray diffraction pattern (XRD pattern) of the compound Sr according to Example 10. _0.985 Tb _0.01 ZnO ₂ FIG. 9 shows a powder X-ray diffraction pattern (XRD pattern) of the compound Sr according to Example 13. _0.985 Pr _0.01 ZnO ₂ 1 shows a powder X-ray diffraction pattern (XRD pattern). The numerical value on the horizontal axis in the figure is 2θ / deg. And the vertical axis indicates diffraction intensity (Intensity / counts).
[0030]
<Emission spectrum of phosphor>
The emission spectrum of the phosphor according to each example when excited by ultraviolet light was examined. In Examples 1 to 8, ultraviolet light having a wavelength of 283 nm was used. In Example 9, ultraviolet light having a wavelength of 281 nm was used. In Examples 10 and 13, ultraviolet light having a wavelength of 282 nm was used.
That is, the raw material powders were mixed and fired, then crushed and sieved to remove the coarse particles, and the phosphor powder was directly charged into a glass holder. Next, the glass holder filled with the phosphor powder was placed in a sample chamber of a spectrofluorometer (F-4500, manufactured by Hitachi, Ltd.), and the emission spectrum (400 to 700 nm) was measured at the above excitation wavelength. The results are shown in FIG. 2 (Examples 1 to 8), FIG. 10 (Example 9), FIG. 11 (Example 10) and FIG. 12 (Example 13). The numerical value on the horizontal axis in the figure is the wavelength (nm), and the vertical axis shows the relative intensity (Normalized intensity). Table 1 shows the emission peak positions (wavelengths) of Examples 1 to 8.
As is clear from FIG. 2 and Table 1, the phosphors having an activator (Mn) concentration of 3 mol% or less (Examples 1 to 4: those in which x in the figure is 0.005 to 0.03) The peak position of the emission spectrum is around 577 to 578 nm. Accordingly, the phosphors of these examples are particularly suitable as a phosphor for emitting yellow light. On the other hand, phosphors having an activator (Mn) concentration of 5 mol% or more (Examples 5 to 8: those in which x in the drawing is 0.05 to 0.2) have a peak position of the emission spectrum of 578 nm. Are also shifted to the longer wavelength side (580-596 nm). Therefore, the phosphors of these embodiments are particularly suitable as phosphors for emitting orange to red light.
[0031]
As is clear from FIGS. 2 and 10, the phosphor of Example 9 (Sr _0.9 Ba _0.1 Zn _0.99 Mn _0.01 O ₂ ) Is the phosphor (SrZn) of Example 2 in which Ba is not substituted. _0.99 Mn _0.01 O ₂ ) Was confirmed to be a phosphor capable of obtaining the same level of emission intensity as that of the phosphor.
As is clear from FIG. 11, the phosphor of Example 10 having Tb, a kind of rare earth, as the emission center has a peak position of the emission spectrum near 550 nm. Therefore, the phosphor of this embodiment is suitable as a greenish-yellow (yellow-green) light-emitting phosphor.
As is clear from FIG. 12, the phosphor of Example 13 having Pr, which is a rare earth element, as the light emission center has a peak position of the light emission spectrum at both around 500 nm and around 600 to 660 nm. Therefore, the phosphor of this example is suitable as a phosphor for yellow light emission, which is a mixture of green and red and is visually recognized as yellow.
[0032]
[Table 1]

[0033]
Next, conventional Mn-activated oxide phosphors were manufactured as Comparative Examples 1 to 5, the emission spectrum was examined in the same manner as above, and the emission peak position (wavelength) was examined.
That is, the parent material is changed to ZnGa by the same procedure as in the above production example while appropriately selecting the raw material and the mixing molar ratio. ₂ O ₄ , ZnAl ₂ O ₄ , Zn ₂ SiO ₄ , Zn ₂ GeO ₄ Or MgGa ₂ O ₄ In this case, a total of five kinds of oxide phosphors in which the activator was Mn (however, the activator concentration (mole percentage) with respect to the base substance was 1 mol%) were prepared. Next, the emission spectrum of the phosphor according to each comparative example when excited by ultraviolet light having a wavelength of 283 nm was examined. Table 2 shows the peak position (wavelength) in the emission spectrum of each comparative example together with the peak position of Example 2.
As is clear from Table 2, the conventional oxide phosphors (Comparative Examples 1 to 5) obtained by doping Mn into the above five kinds of base materials all have emission peak wavelengths in the range of 500 to 540 nm. This was clearly different from the emission peak wavelength range of the phosphor according to the present invention.
[0034]
[Table 2]

[0035]
<Emission evaluation of phosphor>
Next, in order to evaluate the light emission performance of the phosphors according to Examples 1 to 8, the luminance (light emission intensity) at the light emission peak wavelength of the phosphor according to each example was compared. As a result, the phosphor of Example 2 (Mn concentration: 1 mol%) showed the highest luminance. FIG. 3 is a graph showing the relative luminance (relative intensity) of the phosphor according to each example when the luminance (emission intensity) of the phosphor of Example 2 is set to 1. The value on the horizontal axis in the figure is Mn ²⁺ The concentration is (x), and the vertical axis indicates the relative intensity (Normalized intensity).
As is clear from this graph, all of the phosphors having a Mn concentration of 0.5 mol% to 3 mol% (Examples 1 to 4) have a high luminance centering on the phosphor having a Mn concentration of 1 mol% (Example 2). (A relative intensity of 0.5 or more as shown). Among them, the phosphors of Examples 1 to 3 achieved particularly high luminance (relative intensity of 0.7 or more as shown).
As shown in the figure, the present invention doped with an activator (here, Mn) such that the activator concentration is 0.2 to 3 mol% (particularly preferably 0.4 to 2 mol%) with respect to the base substance. Has a peak intensity of about 80% of a commercially available ZnS: Cu, Al phosphor in an emission spectrum excited by ultraviolet light. From this, it was confirmed that it was a phosphor for yellow light emission which was excellent in practicality.
[0036]
Similarly, in order to evaluate the light emission performance of the phosphors according to Examples 10 to 12, the luminance (emission intensity) at the emission peak wavelength of the phosphor according to each example was compared. As a result, the phosphor of Example 10 (Tb concentration: 1 mol%) showed the highest luminance. FIG. 13 is a graph showing the relative luminance (relative intensity) of the phosphor according to each example when the luminance (emission intensity) of the phosphor of Example 10 is set to 1. Numerical values on the horizontal axis in the figure are Tb concentrations (x), and the vertical axis shows relative intensity (Relative intensity). As is clear from this graph, the phosphors having a Tb concentration of 1 mol% (Example 10) and the phosphors having a Tb concentration of 1 mol% to 5 mol% (Examples 10 to 12) all have high luminance (illustrated). As described above).
[0037]
Further, in order to evaluate the light emission performance of the phosphors according to Examples 13 to 15, the luminance (light emission intensity) at the light emission peak wavelength of the phosphor according to each example was compared. As a result, the phosphor of Example 13 (Pr concentration: 1 mol%) showed the highest luminance. FIG. 14 is a graph showing the relative luminance (relative intensity) of the phosphor according to each example when the luminance (emission intensity) of the phosphor of Example 13 is set to 1. The numerical value on the horizontal axis in the figure is the Pr concentration (x), and the vertical axis is the relative intensity (Relative intensity).
As is clear from this graph, the phosphors having a Pr concentration of 1 mol% (Example 13) and the phosphors having a Pr concentration of 1 mol% to 5 mol% (Examples 13 to 15) all have high brightness (illustrated). As described above).
[0038]
<Example of manufacturing fluorescent display tube>
Next, an example in which the phosphor (for example, Examples 1 to 4) obtained in the above production example is applied to a VFD will be described. FIG. 4 is a perspective view showing the fluorescent display tube 10 according to the present embodiment with a part thereof cut away.
The present fluorescent display tube 10 includes a substrate 12 made of a green material such as glass, ceramics, or enamel and provided with a plurality of phosphor layers 20S, 20D, and 20N as fluorescent elements formed in a predetermined light emitting pattern. A glass spacer 14, a transparent cover glass plate 16, a plurality of anode terminals 18P, a plurality of grid terminals 18G, a cathode 18K, and an auxiliary grid terminal 18SG are provided.
Thus, the substrate 12, the spacer 14, and the cover glass plate 16 are sealed with glass to form an airtight container, and a vacuum space surrounded by these members is formed therein. .
[0039]
On the display surface 19 of the fluorescent display tube 10 covered by the vacuum space of the substrate 12, a plurality of phosphor layers 20S representing a segmented “8” character shape, one phosphor layer 20D representing a dot shape, One phosphor layer 20 </ b> N or the like forming a “1” character shape is arranged. Each of the phosphor layers 20S, 20D, and 20N is surrounded by a grid electrode 22 and an auxiliary grid electrode 24, respectively.
The ones of the phosphor layers 20S, 20D, and 20N, which are predetermined at each display digit, are connected to the anode terminals 18P via anode printed wirings 34 (FIG. 6) described later. Have been. Each grid electrode 22 is connected to each grid terminal 18G via a grid wiring 26, and each auxiliary grid electrode 24 is connected to each auxiliary grid terminal 18SG via an auxiliary grid wiring 28.
[0040]
Further, a pair of filament supporting frames 30 (only one located on the right side in FIG. 4 is provided) provided with the cathode terminal 18K are fixed to both ends of the substrate 12, respectively. A plurality of thin filaments (filament cathodes) 32 functioning as a direct heating type cathode (cathode) are parallel to the substrate 30 and are separated from the display surface 19 of the substrate 12 by a predetermined distance. It is stretched to be at the height position.
The filament 32 is made of, for example, a tungsten wire or the like whose surface is coated with an oxide solid solution of an alkaline earth metal having a relatively low work function such as (Ba, Sr, Ca) O as an electron emission layer. It is.
[0041]
FIG. 5 and FIG. 6, which is a cross-sectional view taken along the line VI-VI of FIG. 5, show a configuration near a phosphor layer 20S having an “8” character shape, which is one of the display patterns provided on the display surface 19, and a cross-sectional structure thereof. FIG.
As shown in these drawings, on the display surface 19 of the substrate 12, an anode printed wiring 34 connected to the anode terminal 18P is formed by a thick film screen printing method, a vapor deposition method, or the like. An insulator layer 38 formed at a predetermined thickness and appropriately provided with a through hole 36 penetrating in the thickness direction is fixed thereon. The insulator layer 38 is formed by a thick film screen printing method or the like, and is made of a low-melting glass and a coloring pigment.
[0042]
On the insulator layer 38, a graphite layer 40 having a pattern similar to the phosphor layer 20S but having a slightly larger pattern is formed at a position where the graphite layer 40 is electrically connected to the anode printed wiring 34 via the through hole 36. I have. This graphite layer 40 functions as an anode of the display tube 10. In the present embodiment, the phosphor layers 20S, 20D, and 20N are formed by printing a thick-film phosphor paste on the graphite layer 40, and the acceleration voltage is reduced through the graphite layer 40. It is configured to be applied.
For the phosphor layers 20S, 20D, and 20N, phosphors of the present invention having emission colors such as R (red) and Y (yellow) are appropriately selected and used. That is, the phosphor layers 20S, 20D, and 20N can be formed by printing the paste made of the phosphor of the present invention on the graphite layer 40 in a thick film shape.
[0043]
On the other hand, on the periphery of the phosphor layer 20S, a rib-like wall 44 which is in contact with and surrounds the outer peripheral edge thereof is erected from the graphite layer 40 toward the filament 32. Further, the rib-like wall 44 is surrounded by an auxiliary rib-like wall 46 erected on the green body layer 38. The rib-like wall 44 and the auxiliary rib-like wall 46 are made of a low-melting glass, an inorganic filler such as alumina, or the like, have the same height dimensions, and have an upper end that is higher than that of the phosphor layer 20S. Located on the upper side.
[0044]
The grid electrode 22 and the auxiliary grid electrode 24 are thick-film conductors mainly composed of particulate conductive substances such as graphite, silver, palladium, copper, aluminum, and nickel. The rib-shaped wall 44 and the auxiliary rib-shaped wall 46 are provided with a predetermined thickness on tops. The grid electrode 22 and the auxiliary grid electrode 24 are formed by the grid wiring 26 and the auxiliary grid wiring 28 formed on the insulator layer 38, and the grid pad 48 and the auxiliary grid pad 50 formed continuously therefrom. Are connected to the grid terminal 18G and the auxiliary grid terminal 18SG, respectively.
[0045]
As shown in FIG. 4, at the left end of the fluorescent display tube 10, that is, at one end in the longitudinal direction, an exhaust pipe 52 made of cylindrical glass is provided. In the manufacturing process of the fluorescent display tube 10, the above-described substrate 12, the spacer 14, and the cover glass plate 16 are sealed with glass to form an airtight container. The tip is blown off by a gas burner or the like after the end of evacuation.
[0046]
When driving the fluorescent display tube 10 configured as described above, an acceleration voltage is sequentially applied to each grid electrode 22 in a state where a predetermined heat current is constantly flowing through the filament 32, and a plurality of synchronous voltages are applied in synchronization with the acceleration voltage. An acceleration voltage is applied via the graphite layer 40 to any one of the phosphor layers 20S, 20D, and 20N to emit light. Thereby, the thermoelectrons emitted from the filament 32 are accelerated by the grid electrode 22 to which the acceleration voltage is applied. Thus, when an accelerating voltage force is also applied to the phosphor layers 20S, 20D, and 20N surrounded by the phosphor layers, the thermoelectrons collide and the phosphor layers 20S, 20D, and 20N emit light. Here, the grid electrode 22 is a control electrode for controlling the arrival of thermoelectrons to the phosphor layers 20S, 20D, 20N, and the auxiliary grid electrode 24 eliminates the influence of the negative electric field formed by the surrounding grid electrodes 22. Thus, the thermoelectrons are uniformly directed to the phosphor layers 20S, 20D and 20N. The details of such a driving method are not particularly necessary for understanding the phosphor of the present invention, and are well known and common knowledge of those skilled in the art.
[0047]
In this embodiment, some of the phosphors of the present invention as manufactured in each of the above embodiments are applied to the phosphor layers 20S, 20D and 20N. That is, in the present embodiment, a paste containing the phosphor of the present invention and an appropriate vehicle as the main components shown below (the paste preparation method and the material selection such as the vehicle to be used may be the same as the conventional paste) on the graphite layer 40. The phosphor layers 20S, 20D, and 20N were formed by printing a thick film (not particularly limited).
In this embodiment, the second embodiment, namely, SrZn _0.99 Mn _0.01 O ₂ Are used for the phosphor layers 20S, 20D, and 20N. As a result, high-brightness yellow light emission was realized by the irradiated low-speed electron beam (for example, 30 V). No noticeable charge-up phenomenon was observed.
[0048]
As mentioned above, although the specific example of this invention was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and alterations of the specific examples illustrated above.
In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.
[Brief description of the drawings]
FIG. 1 is a graph showing a powder X-ray diffraction pattern (XRD pattern) of a phosphor according to an example.
FIG. 2 is a graph showing emission spectra of phosphors according to some examples when excited by ultraviolet light.
FIG. 3 is a graph showing the relationship between Mn concentration and emission intensity in the phosphor of the present invention.
FIG. 4 is a partially cutaway perspective view of a fluorescent display tube in one embodiment.
FIG. 5 is a partial plan view showing the vicinity of a phosphor layer in FIG.
FIG. 6 is a sectional view taken along line VI-VI in FIG. 5;
FIG. 7 is a graph showing a powder X-ray diffraction pattern (XRD pattern) of a phosphor according to an example.
FIG. 8 is a graph showing a powder X-ray diffraction pattern (XRD pattern) of a phosphor according to an example.
FIG. 9 is a graph showing a powder X-ray diffraction pattern (XRD pattern) of a phosphor according to an example.
FIG. 10 is a graph showing an emission spectrum of a phosphor according to an example, which is excited by ultraviolet light.
FIG. 11 is a graph showing an emission spectrum of a phosphor according to an example when excited by ultraviolet light.
FIG. 12 is a graph showing an emission spectrum of a phosphor according to an example, which is excited by ultraviolet light.
FIG. 13 is a graph showing the relationship between the Tb concentration and the emission intensity in the phosphor of the present invention.
FIG. 14 is a graph showing the relationship between Pr concentration and emission intensity in the phosphor of the present invention.
[Explanation of symbols]
10. Fluorescent display tube
20S, 20D, 20N phosphor layer

Claims (10)

General _{formula: A x B y Sr 1-} x-y ZnO 2
Here, A and B in the formula are mutually different elements selected from the group consisting of Mg, Ca and Ba, and x and y are 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ x + y ≦ 1. A number that satisfies;
A phosphor substantially composed of a composite oxide represented by the formula and a metal element constituting a luminescence center doped in the composite oxide. The phosphor according to claim 1, wherein the phosphor includes Mn as a metal element constituting the emission center. General _{formula: A x B y Sr 1-} x-y Zn 1-z Mn z O 2
Here, A and B in the formula are mutually different elements selected from the group consisting of Mg, Ca and Ba, and x and y are 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ x + y ≦ 1. And z is a number that satisfies 0.001 ≦ z ≦ 0.05;
The phosphor according to claim 2, which is represented by: The phosphor according to any one of claims 1 to 3, wherein both x and y are 0. The phosphor according to claim 1, wherein the phosphor includes a rare earth element as a metal element constituting the emission center. The phosphor according to claim 5, wherein the phosphor includes Tb as the rare earth element. The phosphor according to claim 5, wherein Pr is contained as the rare earth element. General _{formula: A x B y Sr 1-} x-y- (3/2) z RE z ZnO 2
Here, A and B in the formula are mutually different elements selected from the group consisting of Mg, Ca and Ba, and x and y are 0 ≦ x ≦ 1− (3/2) z and 0 ≦ y ≦ 1 − (3/2) z and 0 ≦ x + y ≦ 1− (3/2) z, z is a number satisfying 0.001 ≦ z ≦ 0.05, and RE is 1 or 2 or more. Is a rare earth element;
The phosphor according to any one of claims 5 to 7, which is represented by: The phosphor according to any one of claims 5 to 8, wherein both x and y are 0. In a fluorescent display device including a substrate, an electrode, and a phosphor,
A fluorescent display device, wherein at least a part of the phosphor is formed of the phosphor according to any one of claims 1 to 9.

Images