JP2006286447A

JP2006286447A - External electrode type fluorescent lamp and backlight unit

Info

Publication number: JP2006286447A
Application number: JP2005105908A
Authority: JP
Inventors: Hideki Wada; 英樹和田; Taizo Ono; 泰蔵小野; Toshihiro Terada; 年宏寺田
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2005-04-01
Filing date: 2005-04-01
Publication date: 2006-10-19

Abstract

<P>PROBLEM TO BE SOLVED: To provide an external electrode type fluorescent lamp having a long life, wherein an effective light emitting length is lengthened to the maximum extent with respect to the length of a lamp without requiring a complicated process to mechanically peel off a phosphor coat, and lowering of a luminous flux maintenance factor and generation of a discharge holes in a glass bulb are suppressed, and to provide a backlight unit. <P>SOLUTION: A phosphor layer 108 emitting red, green, and blue light and containing phosphor particles of respective colors is formed on the inner surface of a glass bulb 101 in which noble gas and mercury are filled, and external electrodes 102, 103 are provided at both end parts 104, 105 of the glass bulb. The external electrodes 102, 103 are formed of a transparent electrode film, and the phosphor layer 108 are formed as far as the inside of the regions of the external electrodes 102, 103, and a metal oxide 109 is deposited on the surface of the phosphor particles in the uppermost layer existing at least on its surface close to the center of a tube. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、外部電極型蛍光ランプおよびこの外部電極型蛍光ランプを搭載したバックライトユニットに関する。 The present invention relates to an external electrode fluorescent lamp and a backlight unit equipped with the external electrode fluorescent lamp.

近年、大型液晶テレビの普及がめざましく、この大型液晶テレビに用いられている直下方式のバックライトユニット（以下「ＬＣＢＬユニット」という）の需要が増大している。 In recent years, the spread of large-sized liquid crystal televisions is remarkable, and the demand for direct-type backlight units (hereinafter referred to as “LCBL units”) used in large-sized liquid crystal televisions is increasing.

ＬＣＢＬユニット用の光源としては、内部にホロー電極を有する冷陰極蛍光ランプ（特許文献１参照）が一般的であるが、複数灯を点灯するためには同数の高周波電子安定器が必要である等の諸事情により、他の光源の利用が検討されている。 As a light source for the LCBL unit, a cold cathode fluorescent lamp having a hollow electrode inside (refer to Patent Document 1) is generally used, but the same number of high-frequency electronic ballasts are necessary for lighting a plurality of lamps, etc. Due to these circumstances, the use of other light sources is being studied.

ここで誘電体バリア放電ランプ（以下、「外部電極型蛍光ランプ」という）は、複数灯を１つの高周波電子安定器により点灯できるというメリットがあるので、例えば１６灯のランプが用いられるＬＣＢＬユニットの光源として好適である。 Here, the dielectric barrier discharge lamp (hereinafter referred to as “external electrode type fluorescent lamp”) has an advantage that a plurality of lamps can be lit by one high-frequency electronic ballast, so that, for example, an LCBL unit using 16 lamps is used. Suitable as a light source.

図６に示すような従来の外部電極型蛍光ランプ１は、前記冷陰極蛍光ランプに対して、ガラスバルブ２における長手方向の有効発光長を長くし、かつ、ホロー電極のスパッタリングによる水銀消耗を抑制して光維持率を向上させるために、希ガスと水銀とを封入して両端を閉塞するとともに、内面に蛍光体被膜３を設けたガラスバルブ２を形成し、ガラスバルブ２の両端部の外面に外部電極５、６を配置し、光投射用の開口部７に対応する部位の外部電極５、６の一部を除去したものである（特許文献２参照）。
特開平９−８２２７５号公報特開２００３−１９７１５３号公報 The conventional external electrode fluorescent lamp 1 as shown in FIG. 6 has a longer effective light emission length in the longitudinal direction of the glass bulb 2 than the cold cathode fluorescent lamp, and suppresses mercury consumption due to sputtering of the hollow electrode. In order to improve the light maintenance rate, a rare gas and mercury are enclosed to close both ends, and the glass bulb 2 having the phosphor coating 3 provided on the inner surface is formed, and the outer surfaces of both ends of the glass bulb 2 are formed. The external electrodes 5 and 6 are arranged on the surface, and a part of the external electrodes 5 and 6 corresponding to the opening 7 for light projection is removed (see Patent Document 2).
Japanese Patent Laid-Open No. 9-82275 JP 2003-197153 A

しかしながら、上記のような従来の外部電極型蛍光ランプ１にあっては、ガラスバルブ２に光投射用の開口部７とその開口部７に対応する部位を除去した外部電極５、６とを必要とし、特に、光投射用の開口部７の形成には、ガラスバルブ２の内面に蛍光体を塗布し乾燥した後、ガラスバルブ２内に剥離爪を有するスクレーパを挿入し管軸方向に進行させ、ガラスバルブ２内に形成された蛍光体被膜３を剥離爪で機械的に剥ぐ等の複雑な工程を必要とし、そして、この工程は、ガラスバルブ２の管径の細いもの及び長さの長いものに制限があるという問題があった。 However, in the conventional external electrode fluorescent lamp 1 as described above, the glass bulb 2 needs the light projection opening 7 and the external electrodes 5 and 6 from which portions corresponding to the opening 7 are removed. In particular, the opening 7 for light projection is formed by applying a phosphor on the inner surface of the glass bulb 2 and drying it, and then inserting a scraper having a peeling claw into the glass bulb 2 to advance in the tube axis direction. In addition, a complicated process such as mechanically peeling the phosphor coating 3 formed in the glass bulb 2 with a peeling claw is required, and this step has a small tube diameter and a long length. There was a problem that things were limited.

また、ガラスバルブ２の内面に形成された蛍光体被膜３において、特にアルミナを含む青色の蛍光体粒子は、他のアルミナを含まない赤色、緑色の蛍光体粒子より水銀が吸着しやすくライフ期間中の光束維持率の低下が大きく、かつ、外部電極５、６の領域の蛍光体粒子への水銀付着が起因して外部電極５、６の領域のガラスバルブ２に放電穴が発生し、不点灯になるという問題があった。 In addition, in the phosphor coating 3 formed on the inner surface of the glass bulb 2, blue phosphor particles containing alumina in particular tend to adsorb mercury more easily than other red and green phosphor particles not containing alumina during the life period. In the area of the external electrodes 5 and 6, the glass bulb 2 in the area of the external electrodes 5 and 6 has a discharge hole, resulting in a non-lighting. There was a problem of becoming.

本発明は、上記のような問題点に鑑みてなされたもので、蛍光体被膜を機械的に剥ぐ等の複雑な工程を必要とせず、ランプ長に対して有効発光長を最大限に長くし、かつ、光束維持率の低下およびガラスバルブの放電穴の発生を抑制した長寿命の外部電極型蛍光ランプおよびバックライトユニット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 does not require a complicated process such as mechanically peeling off the phosphor film, and maximizes the effective light emission length with respect to the lamp length. An object of the present invention is to provide a long-life external electrode type fluorescent lamp and a backlight unit that suppresses a decrease in luminous flux maintenance factor and the occurrence of discharge holes in a glass bulb.

上記の目的を達成するために、本発明の請求項１に記載された外部電極型蛍光ランプは、希ガスおよび水銀が封入されたガラスバルブの内面に、赤色、緑色、青色の光を発する各色の蛍光体粒子を含む蛍光体層が形成されており、前記ガラスバルブの両端部の外側に外部電極とを備えた外部電極型蛍光ランプにおいて、前記外部電極が透明電極膜で形成されているとともに、前記蛍光体層が前記外部電極の領域内まで形成され、かつ、少なくとも管中心に近い面にある最上層の前記蛍光体粒子の表面に金属酸化物が付着されていることを特徴とする。 In order to achieve the above object, an external electrode type fluorescent lamp according to claim 1 of the present invention provides each color that emits red, green, and blue light on the inner surface of a glass bulb in which rare gas and mercury are sealed. In the external electrode type fluorescent lamp in which a phosphor layer containing the phosphor particles is formed and the external electrode is provided outside the both ends of the glass bulb, the external electrode is formed of a transparent electrode film. The phosphor layer is formed up to the region of the external electrode, and a metal oxide is attached to the surface of the phosphor particles in the uppermost layer at least near the center of the tube.

上記目的を達成するために、本発明に係るバックライトユニットは、直下型のバックライトユニットであって、上記外部電極型蛍光ランプを複数本と、前記複数本の外部電極型蛍光ランプの全て点灯させる１個の高周波電子安定器とを備える液晶テレビに用いられる直下型のバックライトユニットであって、上記蛍光ランプを複数本と、複数本の蛍光ランプの全て点灯させる１個の高周波電子安定器とを備えることを特徴とする。 In order to achieve the above object, a backlight unit according to the present invention is a direct backlight unit, and a plurality of the external electrode fluorescent lamps and the plurality of external electrode fluorescent lamps are all turned on. A direct-type backlight unit used in a liquid crystal television including one high-frequency electronic ballast to be operated, and a single high-frequency electronic ballast that turns on the plurality of fluorescent lamps and all of the plurality of fluorescent lamps It is characterized by providing.

課題を解決するための手段に記載した構成により、蛍光体被膜を機械的に剥ぐ等の複雑な工程を必要とせず、ランプ長に対して有効発光長を最大限に長くし、かつ、光束維持率の低下及びガラスバルブの放電穴の発生を抑制した外部電極型蛍光ランプおよびバックライトユニットを提供することができるものである。 With the configuration described in the means for solving the problem, the effective light emission length is maximized with respect to the lamp length and the luminous flux is maintained without requiring a complicated process such as mechanically peeling the phosphor film. Thus, it is possible to provide an external electrode type fluorescent lamp and a backlight unit in which the reduction in the rate and the occurrence of the discharge hole of the glass bulb are suppressed.

（実施の形態１）
図１は、本発明の実施の形態１における液晶テレビの概要を示す図である。 (Embodiment 1)
FIG. 1 is a diagram showing an outline of a liquid crystal television according to Embodiment 1 of the present invention.

図１に示す液晶テレビ１０は、例えば３２吋液晶テレビであり、液晶画面ユニット１１とバックライトユニット１２とを備える。 A liquid crystal television 10 shown in FIG. 1 is, for example, a 32-inch liquid crystal television, and includes a liquid crystal screen unit 11 and a backlight unit 12.

液晶画面ユニット１１は、カラーフィルタ基板、液晶、ＴＦＴ基板、駆動モジュール等（図示せず）を備え、外部からの画像信号に基づいてカラー画像を形成する。 The liquid crystal screen unit 11 includes a color filter substrate, a liquid crystal, a TFT substrate, a drive module and the like (not shown), and forms a color image based on an image signal from the outside.

バックライトユニット１２は、ＬＣＢＬユニットであり、１個の高周波電子安定器１３と、１６本の外部電極型蛍光ランプ１００を含む。また、図２に示すようなソケット台５０は、１６本の外部電極型蛍光ランプ１００の両端を、弾性のあるステンレス、りん青銅等からなる電極ソケット５１及び電極ソケット５２に保持し、ランプ点灯させるものである。 The backlight unit 12 is an LCBL unit and includes one high-frequency electronic ballast 13 and 16 external electrode type fluorescent lamps 100. Further, the socket base 50 as shown in FIG. 2 holds both ends of the 16 external electrode type fluorescent lamps 100 on the electrode socket 51 and the electrode socket 52 made of elastic stainless steel, phosphor bronze or the like, and lights the lamp. Is.

高周波電子安定器１３は、１６本の外部電極型蛍光ランプ１００の全てを点灯させる点灯回路である。 The high-frequency electronic ballast 13 is a lighting circuit that lights all 16 external electrode type fluorescent lamps 100.

図３は、本発明の実施の形態１における外部電極型蛍光ランプ１００の概要を示す図である。 FIG. 3 is a diagram showing an outline of the external electrode fluorescent lamp 100 according to Embodiment 1 of the present invention.

図３に示すように、本発明の実施の形態１における外部電極型蛍光ランプ１００は、管状のガラスバルブ１０１の両端部外周に、リング状の透明電極膜が形成された外部電極１０２、１０３を設け、ガラスバルブ１０１の両端封着部１０４、１０５に、外部電極の一端部１０２ｂ、１０３ｂを被覆し、かつ、封着部１０４、１０５を保温する保温体１０６、１０７、例えば厚みが０．０５〜２ｍｍのシリコンゴム、エポキシ樹脂等の絶縁体を設けている。外部電極１０２、１０３（以下、「透明電極膜１０２、１０３」ともいう）は、約厚みが１０００オングストローム以上のＩＴＯ又はＳｎＯ₂が蒸着法により蒸着された薄膜である。 As shown in FIG. 3, the external electrode fluorescent lamp 100 according to Embodiment 1 of the present invention includes external electrodes 102 and 103 each having a ring-shaped transparent electrode film formed on the outer periphery of both ends of a tubular glass bulb 101. A heat insulating body 106, 107, for example, having a thickness of 0.05, for covering both end sealing portions 104, 105 of the glass bulb 101 with one end portions 102b, 103b of the external electrode and keeping the sealing portions 104, 105 warm. An insulator such as silicon rubber of 2 mm or epoxy resin is provided. The external electrodes 102 and 103 (hereinafter also referred to as “transparent electrode films 102 and 103”) are thin films in which ITO or SnO ₂ having a thickness of about 1000 Å or more is deposited by a deposition method.

ガラスバルブ１０１内面には、赤色（Ｙ₂Ｏ₃：Ｅｕ³⁺）、緑色（ＬａＰＯ₄：Ｃｅ³⁺，Ｔｂ³⁺）及び青色（ＢａＭｇ₂Ａｌ₁₆Ｏ₂₇：Ｅｕ²⁺）の光を発する各色の蛍光体粒子を混合した希土類蛍光体が塗布されて、厚さ１０μｍ〜２０μｍの蛍光体層１０８が形成されている。蛍光体層１０８は、ランプ長手方向の有効発光長を大きくするために外部電極１０２、１０３の領域内まで形成され、かつ、少なくとも管中心に近い面にある最上層の蛍光体粒子の表面に波長２５４ｎｍの光を透過する物質からなるＹ₂Ｏ₃、ＭｇＯ、Ｌａ₂Ｏ₃又はＳｉＯ₂の金属酸化物１０９が付着されている。 The inner surface of the glass bulb 101 emits red (Y ₂ O ₃ : Eu ³⁺ ), green (LaPO ₄ : Ce ³⁺ , Tb ³⁺ ) and blue (BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ) light. A rare earth phosphor in which phosphor particles of each color are mixed is applied to form a phosphor layer 108 having a thickness of 10 μm to 20 μm. The phosphor layer 108 is formed up to the region of the external electrodes 102 and 103 in order to increase the effective light emission length in the lamp longitudinal direction, and at least the wavelength of the phosphor layer 108 on the surface of the uppermost phosphor particle in the plane close to the tube center. A Y ₂ O ₃ , MgO, La ₂ O ₃ or SiO ₂ metal oxide 109 made of a material that transmits light of 254 nm is attached.

ガラスバルブ１０１の内部には圧力が約８ｋＰａのアルゴン及ネオン等の希ガス１１０と、約２ｍｇの水銀１１１が充填されている。 The glass bulb 101 is filled with a rare gas 110 such as argon and neon having a pressure of about 8 kPa and about 2 mg of mercury 111.

本実施の形態では、ガラスバルブ１０１は、断面が略円状の放電容囲器であって、例えばホウ珪酸ガラスからなり、外径φ４.０ｍｍ、内径φ３.０ｍｍ、全長７２０ｍｍの直形ガラスバルブである。このガラスバルブ１０１の封着部１０４、１０５は、例えば、ガラスバルブ１０１の端部に破線で示すビードガラス１１２、１１３を挿入し、その挿入されているビードガラス１１２、１１３周辺をガスバーナーにより加熱溶融させることで行っている。封止後のガラスバルブ１０１においては、その端部の内周面の形状が略同じになっている。正確に言うと、封着部１０４における放電空間に面する部分１１２ａには、ガラスバルブ１０１の端側に凹入する凹部１１２ｂがある。逆に、封着部１０４における放電空間に面する部分１１２ａに放電空間側に突出する部分があると、放電空間ロスを招くことになるが、放電空間と反対側（ガラスバルブ１０１の端側）に凹入する凹部１１２ｂの場合、放電空間ロスを招く惧れがなく、封着部１０４、１０５における放電空間に面する部分１１２ａ、１１３ａの形状が略等しいとみなすことができる。これにより、透明電極膜１０２の領域と透明電極膜１０３の領域のガラスバルブ１０１で形成される第１のコンデンサと第２のコンデンサとの静電容量を実質的に等しくすることができる。 In the present embodiment, the glass bulb 101 is a discharge envelope having a substantially circular cross section, and is made of, for example, borosilicate glass, and has a diameter of 4.0 mm, an inside diameter of 3.0 mm, and a total length of 720 mm. It is. In the sealing portions 104 and 105 of the glass bulb 101, for example, bead glasses 112 and 113 indicated by broken lines are inserted into the end portion of the glass bulb 101, and the periphery of the inserted bead glasses 112 and 113 is heated by a gas burner. It is done by melting. In the glass bulb 101 after sealing, the shape of the inner peripheral surface of the end portion is substantially the same. To be exact, a portion 112 a facing the discharge space in the sealing portion 104 has a recess 112 b that is recessed into the end side of the glass bulb 101. On the contrary, if there is a portion projecting toward the discharge space in the portion 112a facing the discharge space in the sealing portion 104, a discharge space loss is caused, but the side opposite to the discharge space (the end side of the glass bulb 101). In the case of the concave portion 112b that is recessed in, there is no possibility of causing a loss of the discharge space, and the shapes of the portions 112a and 113a facing the discharge space in the sealing portions 104 and 105 can be regarded as substantially equal. Thereby, the electrostatic capacitance of the 1st capacitor | condenser formed with the glass bulb 101 of the area | region of the transparent electrode film 102 and the area | region of the transparent electrode film 103 and a 2nd capacitor | condenser can be made substantially equal.

このときの透明電極膜１０２、１０３におけるガラスバルブ１０１の中央側（内方側）の端面１０２ａ、１０３ａと、ガラスバルブ１０１の端面との距離Ｌ２が２３ｍｍ、また、透明電極膜１０２、１０３の内方側の端面１０２ａ、１０３ａと封着部１０４、１０５が放電空間に面している部分１１２ａ、１１３ａとの距離Ｌ３が２０ｍｍとそれぞれなっている。また、この透明電極膜１０２、１０３の幅Ｌ1、位置等は、バックライトユニットの寸法、接続端子との接続方法等により適宜決定されるが、発光光率を向上させるには、透明電極膜１０２、１０３におけるガラスバルブ１０１の端側（外方側）の端面（端縁）１０２ｂ、１０３ｂが、封着部１０４、１０５が放電空間に面している部分１１２ａ、１１３ａよりも外方側にある方が好ましい。ここでは、金属酸化物１０９は、最上層の蛍光体層１０８の表面上に連続して形成されたＹ₂Ｏ₃の薄膜が付着している。 At this time, the distance L2 between the end surfaces 102a and 103a on the center side (inward side) of the glass bulb 101 in the transparent electrode films 102 and 103 and the end surface of the glass bulb 101 is 23 mm. Distances L3 between the end faces 102a and 103a on the side and the portions 112a and 113a where the sealing portions 104 and 105 face the discharge space are 20 mm, respectively. Further, the width L1, position, and the like of the transparent electrode films 102 and 103 are appropriately determined depending on the dimensions of the backlight unit, the connection method with the connection terminals, and the like. To improve the light emission rate, the transparent electrode film 102 is used. , 103 have end faces (edges) 102b, 103b on the end side (outward side) of the glass bulb 101 on the outer side of the portions 112a, 113a where the sealing portions 104, 105 face the discharge space. Is preferred. Here, a thin film of Y ₂ O ₃ formed continuously on the surface of the uppermost phosphor layer 108 is attached to the metal oxide 109.

なお、実施の形態では、透明電極膜１０２、１０３はリング状に形成されたものであるが、これに限らず、ガラスバルブ１０１の両端封着部１０４、１０５の端面まで覆うキャップ状のものであってもよいし、また、光束維持率を向上させるために、リング状又はキャップ状の透明電極膜１０２、１０３を管軸方向にスリットを設けたものでもよい。このとき、保温体１０６、１０７は、ガラスバルブ１０１の両端封着部１０４、１０５に設けてもよいし、設けなくてもよい。 In the embodiment, the transparent electrode films 102 and 103 are formed in a ring shape. However, the transparent electrode films 102 and 103 are not limited to this, and are cap-shaped ones that cover the end surfaces of the both-end sealing portions 104 and 105 of the glass bulb 101. The ring-shaped or cap-shaped transparent electrode films 102 and 103 may be provided with slits in the tube axis direction in order to improve the luminous flux maintenance factor. At this time, the heat retaining bodies 106 and 107 may or may not be provided at the both end sealing portions 104 and 105 of the glass bulb 101.

また、透明電極膜１０２、１０３は、蒸着法で形成された蒸着膜であるが、これに限らず、デップ法で形成されたデップ膜でもよい。 Moreover, although the transparent electrode films 102 and 103 are vapor deposition films formed by a vapor deposition method, the present invention is not limited thereto, and may be a dep film formed by a dipping method.

また、金属酸化物１０９は、最上層の蛍光体層１０８の表面上に連続して形成されたＹ₂Ｏ₃の薄膜の形態で付着しているが、これに限らず、薄膜の形態ではなく図４に示すようなＹ₂Ｏ₃の微粒子層１０９ａ、或いは図５に示すような各色の蛍光体粒子のうちアルミナを含む蛍光体粒子、例えば青色の蛍光体粒子の表面にＹ₂Ｏ₃の金属酸化膜１０９ｂが被覆されているものでもよい。さらに、前記金属酸化物の材料はＹ₂Ｏ₃であるが、これに限らず、ＭｇＯ、Ｌａ₂Ｏ₃又はＳｉＯ₂でもよい。 Further, the metal oxide 109 is attached in the form of a thin film of Y ₂ O ₃ continuously formed on the surface of the uppermost phosphor layer 108, but is not limited to this, and is not in the form of a thin film. A fine particle layer 109a of Y ₂ O ₃ as shown in FIG. 4 or phosphor particles containing alumina among phosphor particles of each color as shown in FIG. 5, for example, Y ₂ O _{3 on} the surface of blue phosphor particles. The metal oxide film 109b may be covered. Furthermore, the material of the metal oxide is Y ₂ O ₃ , but is not limited thereto, and may be MgO, La ₂ O ₃ or SiO ₂ .

ここでいう、本発明のアルミナを含む蛍光体粒子とは、蛍光体粒子を表す化学式にＡｌ_xＯ_Yが含まれているもの、例えば前記の青色蛍光体粒子をいい、アルミナを含まない蛍光体粒子とは、蛍光体粒子を表す化学式にＡｌ_xＯ_Yが含まれていないもの、例えば前記の赤色及び緑色の蛍光体粒子をいう。 Here, the phosphor particles containing alumina of the present invention are those containing Al _x O _{Y in the} chemical formula representing the phosphor particles, for example, the blue phosphor particles described above, and phosphors containing no alumina. The term “particle” refers to a substance that does not contain Al _x O _{Y in the} chemical formula representing the phosphor particle, for example, the above-described red and green phosphor particles.

また、図５に示す蛍光体層１０８は、アルミナを含まない蛍光体粒子及び金属酸化物を付着させたアルミナを含む蛍光体粒子を混合させたものであるので、アルミナを含まない蛍光体粒子の表面にも僅かな金属酸化物が存在することがある。したがって、本発明の蛍光体粒子のうちアルミナを含む蛍光体粒子の表面のみに金属酸化膜１０９ｂが被覆されているものとは、アルミナを含まない蛍光体粒子に僅少の金属酸化物が付着しているものも含む。つまり、アルミナを含まない蛍光体粒子の表面よりもアルミナを含む蛍光体粒子に、より広い面積で金属酸化物が付着されているものをいう。 Further, the phosphor layer 108 shown in FIG. 5 is a mixture of phosphor particles not containing alumina and phosphor particles containing alumina to which a metal oxide is attached. There may be slight metal oxides on the surface. Therefore, among the phosphor particles of the present invention, only the surface of the phosphor particles containing alumina is coated with the metal oxide film 109b means that a small amount of metal oxide adheres to the phosphor particles not containing alumina. Including those that are. That is, it means that the metal oxide is attached to the phosphor particles containing alumina in a wider area than the surface of the phosphor particles not containing alumina.

また、ガラスバルブ１０１の両端封着部１０４、１０５に、封着部１０４、１０５を保温する保温体１０６、１０７を設けたが、これに限らず、保温体１０６、１０７を必ずしも設けなくてもよい。 In addition, although the heat retaining bodies 106 and 107 for keeping the sealing portions 104 and 105 are provided at the both end sealing portions 104 and 105 of the glass bulb 101, the present invention is not limited to this, and the heat retaining bodies 106 and 107 are not necessarily provided. Good.

次に、上記外部電極型蛍光ランプ１００及びバックライトユニット１２の作用効果について説明する。 Next, functions and effects of the external electrode fluorescent lamp 100 and the backlight unit 12 will be described.

本発明の第１の実施形態における外部電極型蛍光ランプは、外部電極１０２、１０３が透明電極膜で形成されているとともに、蛍光体層１０８が外部電極１０２、１０３の領域内まで形成されているので、上記従来の外部電極型蛍光ランプで説明した蛍光体被膜を機械的に剥ぐ等の複雑な工程を必要とせず、ガラスバルブ１０１の両端封着部を除く中央部領域がランプ長手方向の有効発光長Ｌ４となり、ガラスバルブ１０１の長さ方向の利用効率を向上することができる。また、少なくとも管中心に近い面にある最上層の蛍光体粒子の表面に金属酸化物１０９が付着されているので、蛍光体粒子に水銀が付着しにくく、水銀消耗による光束維持率の低下及びガラスバルブ１０１の放電穴の発生を抑制することができランプを長寿命化することができる。さらに、外部電極１０２、１０３が透明電極膜で形成されているため、ガラスバルブ１０１内への光照射を妨げるものがないので、暗黒始動性も向上することができる。 In the external electrode fluorescent lamp according to the first embodiment of the present invention, the external electrodes 102 and 103 are formed of a transparent electrode film, and the phosphor layer 108 is formed up to the region of the external electrodes 102 and 103. Therefore, a complicated process such as mechanically peeling the phosphor film described in the above-mentioned conventional external electrode fluorescent lamp is not required, and the central region excluding the sealing portions at both ends of the glass bulb 101 is effective in the longitudinal direction of the lamp. The light emission length L4 is achieved, and the utilization efficiency of the glass bulb 101 in the length direction can be improved. In addition, since the metal oxide 109 is attached to the surface of the uppermost phosphor particles at least near the center of the tube, mercury is less likely to adhere to the phosphor particles, and the reduction in luminous flux maintenance due to mercury consumption and glass The occurrence of discharge holes in the bulb 101 can be suppressed, and the life of the lamp can be extended. Furthermore, since the external electrodes 102 and 103 are formed of a transparent electrode film, there is nothing to prevent the light irradiation into the glass bulb 101, so that the dark startability can be improved.

また、本発明の第１の実施形態における外部電極型蛍光ランプは、最上層の蛍光体層１０８の表面上に連続して形成され、かつ１８５ｎｍの紫外線を遮断して２５４ｎｍの紫外線を透過する物質からなるＹ₂Ｏ₃（ＭｇＯ、Ｌａ₂Ｏ₃又はＳｉＯ₂）の薄膜１０９が付着しているので、１８５ｎｍの紫外線を遮断して波長２５４ｎｍの光を蛍光体層１０８へ照射でき、かつ蛍光体層１０８への水銀付着を遮断することができる。その結果、水銀消耗、１８５ｎｍの紫外線等による蛍光体劣化による光束維持率の低下及びガラスバルブ１０１の放電穴の発生を抑制することができランプを長寿命化することができる。 In addition, the external electrode fluorescent lamp in the first embodiment of the present invention is a substance that is continuously formed on the surface of the uppermost phosphor layer 108 and that blocks 185 nm ultraviolet light and transmits 254 nm ultraviolet light. Since a thin film 109 of Y ₂ O ₃ (MgO, La ₂ O ₃ or SiO ₂ ) made of is attached, the phosphor layer 108 can be irradiated with light having a wavelength of 254 nm by blocking 185 nm ultraviolet light. Mercury adhesion to the layer 108 can be blocked. As a result, it is possible to suppress the decrease in the luminous flux maintenance factor due to mercury consumption, phosphor deterioration due to ultraviolet rays of 185 nm, and the occurrence of discharge holes in the glass bulb 101, thereby extending the life of the lamp.

また、本発明の第１の実施形態における外部電極型蛍光ランプは、各色の蛍光体粒子のうちアルミナを含む蛍光体粒子の表面のみに金属酸化膜１０９ｂが被覆されているので、前記薄膜１０９に比べ原材料の高い金属酸化物の使用量を削減できる。 Further, in the external electrode fluorescent lamp according to the first embodiment of the present invention, only the surface of the phosphor particles containing alumina among the phosphor particles of each color is coated with the metal oxide film 109b. The amount of metal oxide, which is a higher raw material, can be reduced.

また、本発明の第１の実施形態における外部電極型蛍光ランプは、透明電極膜１０２、１０３が蒸着法で形成された蒸着膜であるので、デップ法で形成されたデップ膜に比較し、膜の透明度やガラスバルブ１０１との密着度が高くなる。その結果、初期輝度が向上し、かつ、ガラスバルブ１０１と透明電極膜１０２、１０３との間で発生するコロナ放電の発生を抑制することができ、さらに、透明電極膜１０２の領域と透明電極膜１０３の領域のガラスバルブ１０１で形成される第１のコンデンサと第２のコンデンサとの静電容量を実質的に等しくすることができる。 The external electrode fluorescent lamp according to the first embodiment of the present invention is a vapor deposition film in which the transparent electrode films 102 and 103 are formed by a vapor deposition method. Transparency and the degree of adhesion with the glass bulb 101 are increased. As a result, the initial luminance is improved, the occurrence of corona discharge between the glass bulb 101 and the transparent electrode films 102 and 103 can be suppressed, and the region of the transparent electrode film 102 and the transparent electrode film can be suppressed. The capacitances of the first capacitor and the second capacitor formed by the glass bulb 101 in the region 103 can be made substantially equal.

また、本発明の第１の実施形態における外部電極型蛍光ランプは、ガラスバルブ１０１の両端封着部１０４、１０５に、外部電極の一端部１０２ｂ、１０３ｂを被覆し、かつ、封着部１０４、１０５を保温する保温体１０６、１０７を設けていることで、オゾンの発生を抑制することができ、また、封着部１０４、１０５への水銀移動（カタホレシス現象の発生）が低減され、ガラスバルブ１０１の両端部において輝度ムラを抑制することができる。 Further, in the external electrode fluorescent lamp according to the first embodiment of the present invention, both end sealing portions 104, 105 of the glass bulb 101 are covered with one end portions 102b, 103b of the external electrode, and the sealing portion 104, By providing the heat retaining bodies 106 and 107 for keeping the temperature 105, generation of ozone can be suppressed, and mercury movement (occurrence of cataphoresis phenomenon) to the sealing portions 104 and 105 is reduced. Luminance unevenness can be suppressed at both ends of 101.

本発明の第１の実施形態におけるバックライトユニットは、前記外部電極型蛍光ランプを光源として備えることで、透明電極膜１０２、１０３の部分も有効発光長の一部となり、バックライトユニットをコンパクト化することもできる。 The backlight unit according to the first embodiment of the present invention includes the external electrode fluorescent lamp as a light source, so that the transparent electrode films 102 and 103 are also part of the effective light emission length, and the backlight unit is made compact. You can also

また、本発明の第１の実施形態は、直下型のバックライトユニットであって、外部電極型蛍光ランプ１００を複数本と、この複数本の外部電極型蛍光ランプ１００の全て点灯させる１個の高周波電子安定器１３とを備えることで、冷陰極蛍光ランプを搭載したバックライトユニットに比べ、高周波電子安定器の使用数が少ないのでバックライトユニットを安価にすることができる。 The first embodiment of the present invention is a direct-type backlight unit, and includes a plurality of external electrode fluorescent lamps 100 and a single one for lighting all of the plurality of external electrode fluorescent lamps 100. By providing the high-frequency electronic ballast 13, the number of high-frequency electronic ballasts used is smaller than that of a backlight unit equipped with a cold cathode fluorescent lamp, so that the backlight unit can be made inexpensive.

本発明に係る外部電極型蛍光ランプは、コンパクトで有効発光長が長く、かつ、長寿命化することができるので、パソコンの液晶ディスプレイ用、大型液晶テレビ用及び小型液晶テレビ用等のバックライトユニットとして利用可能である。 The external electrode type fluorescent lamp according to the present invention is compact, has a long effective light emission length, and can have a long life. Therefore, the backlight unit for personal computer liquid crystal displays, large liquid crystal televisions, and small liquid crystal televisions is used. Is available as

本発明の実施の形態１における液晶テレビの概要を示す図The figure which shows the outline | summary of the liquid crystal television in Embodiment 1 of this invention 同実施の形態１におけるソケット台５０の概要を示す図The figure which shows the outline | summary of the socket stand 50 in the same Embodiment 1. 同実施の形態１における外部電極型蛍光ランプ１００の概要を示す図The figure which shows the outline | summary of the external electrode type fluorescent lamp 100 in the same Embodiment 1. 同外部電極型蛍光ランプ１００における蛍光体層１０８と金属酸化物の微粒子層１０９ａとの関係を示す図The figure which shows the relationship between the fluorescent substance layer 108 and the metal oxide fine particle layer 109a in the external electrode type fluorescent lamp 100 同外部電極型蛍光ランプ１００におけるアルミナを含む蛍光体粒子と金属酸化物との関係を示す図The figure which shows the relationship between the fluorescent substance particle containing an alumina in the same external electrode type | mold fluorescent lamp 100, and a metal oxide. 従来の外部電極型蛍光ランプ１の概要を示す図The figure which shows the outline | summary of the conventional external electrode type fluorescent lamp 1

Explanation of symbols

１０１ガラスバルブ
１０２、１０３外部電極
１０４、１０５ガラスバルブの封着部
１０８蛍光体層
１０９金属酸化物 101 Glass bulb 102, 103 External electrode 104, 105 Sealed portion of glass bulb 108 Phosphor layer 109 Metal oxide

Claims

A phosphor layer containing phosphor particles of each color emitting red, green, and blue light is formed on the inner surface of a glass bulb in which rare gas and mercury are sealed, and external electrodes are arranged outside both ends of the glass bulb. The external electrode is formed of a transparent electrode film, and the phosphor layer is formed up to the region of the external electrode and is at least on the surface near the tube center An external electrode fluorescent lamp characterized in that a metal oxide is attached to the surface of the phosphor particles in the uppermost layer.

2. The external electrode type fluorescence according to claim 1, wherein the metal oxide has a metal oxide film coated only on the surface of phosphor particles containing alumina among the phosphor particles of the respective colors. lamp.

2. The external electrode type fluorescence according to claim 1, wherein the metal oxide has a thin film of the metal oxide continuously formed on a surface of the uppermost phosphor layer. lamp.

The metal _{_{oxide, Y 2 O 3, MgO,}} La 2 O 3 or the external electrode fluorescent lamp according to any one of claims 1 to 3, characterized in that those containing SiO _2.

The external electrode fluorescent lamp according to any one of claims 1 to 4, wherein the external electrode has a slit in a tube axis direction.

External electrode fluorescent lamp according to any one of claims 1 to 5 wherein the transparent electrode film, characterized in that it is formed of ITO or SnO _2.

The external electrode fluorescent lamp according to any one of claims 1 to 6, wherein the transparent electrode film is a vapor deposition film.

The external electrode fluorescent lamp according to any one of claims 1 to 7, wherein a protective film is formed between the glass bulb and the phosphor layer.

The external electrode fluorescent lamp according to any one of claims 1 to 8, wherein a heat insulator for keeping the temperature of the sealing portion is provided at both end sealing portions of the glass bulb.

A backlight unit comprising the external electrode fluorescent lamp according to any one of claims 1 to 9 as a light source.

A direct-type backlight unit, wherein one of the plurality of external electrode fluorescent lamps according to any one of claims 1 to 9 and all of the plurality of external electrode fluorescent lamps are lit. A high-frequency electronic ballast.