200947502 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種用作液晶顯示裝置等中所使用之背光 裝置、或者小型顯示機器等之顯示裝置之光源的放電燈。 【先前技術】 用作液晶顯示裝置之背光用光源等的放電燈構成如下： 於玻璃管之内表面上塗佈有螢光體而成之發光管上作為電 極設置圓筒或板狀之放電電極，並封入水銀及氖/氬等稀 有氣體’藉由利用來自上述放電電極之放電而於發光管之 内部產生之紫外線來激發螢光體而獲得可見光（專利文獻 1)。 又，於用作如上述般之背光用光源等之情形時，通常使 用複數個放電燈，但為了減少所使用之燈之個數，亦作出 有如下嘗試：使單一玻璃管彎曲成U字型、L字型或者賨字 型，以更少數量之玻璃管使每單位面積之玻璃管之根數實 質性增加（專利文獻1及專利文獻2)。 另一方面，如上所述使單一玻璃管彎曲而形成。字等彎 曲型放電燈時，業者期望將彎曲部配置於發光區域内。其 目的在於有效利用弯曲部之光、及窄邊緣化等。然而，形 成如上所述之構成時，上述發光區域内整體之亮度不安 疋，會產生壳度不均，無法呈現出穩定之發光特性。 [專利文獻1 ]曰本專利特開平8_丨73號 [專利文獻2]曰本專利實開平5_652〇號 【發明内容】 136657.doc 200947502 [發明所欲解決之問題] 本發明係提供-種即便以彎曲部位於開口部内之方式配 置燈’亦能夠抑制顯示裝置之發光區域中之亮度不均的顯 不裝置用之放電燈及使用其之背光裝置。 [解決問題之技術手段] 為了解決上述課題，本發明之一離搓仫 十》ai 態樣係關於一種顯示裝 置用之放電燈，其特徵在於包括：玻璃管，其具有至少兩 個以上之直線部、及形成於上述直線部間之彎曲部；含螢 光體之發光層，其形成於上述玻璃管之内壁面；及放電電 極’其配置於上述玻璃管；i述彎曲部係其剖面為大致擴 圓狀，當將長轴外徑設為R，、將短軸外徑設為R時， R/R，各 0.S。 [發明之效果] 根據上述態樣，即便以彎曲部位於開口部内之方式配置 燈’亦能夠抑制顯示裝置之發光區域中之亮度不均。 【實施方式】 以下’ 一面參照圖式一面說明本發明之實施形態。圖1 係表示本發明之背光裝置一例的概略構成圖，圖2係表示 本發明之放電燈一例的概略構成圖。 如圖1所示’作為顯示裝置一例之本例的背光裝置包括 外殼1、複數個放電燈2、及光學面材3。 外殼1例如由白色塑膠構成，且由前外殼11與後外殼12 所構成。前外殼11係構成外殼1之蓋之部分，其主面上形 成有在本背光裝置中作為發光區域之開口部111。後外殼 136657.doc 200947502 /系構成外殼1之箱的部分’且形成為有底開口形狀。該 後外殼12之内壁面藉由反射片或銀蒸鍍等而具有高反射 性。 士圖2所示，放電燈2係熱陰極螢光燈，且具有由鈉鈣玻 璃等軟質玻璃而構成之玻璃管21作為主要部分。玻璃管21 由直線4 211、彎曲部212及收縮密封部2丨3而構成，且整 體呈子1上述放電燈2如圖3所示，以彎曲部212位於開 4 111内之方式，且以交錯狀、即相鄰接之彎曲部22之 4置為上下反向之交替的方式而並排配置於外般1内。再 者，本例中，放電燈2之數量為4個，但並不限於該數量， 可視需要而設為任意之數量。 直線部211於玻璃管21内係以大致直線狀延伸之部分。 本例中，兩個直線部211平行地位於各玻璃管21中，且其 外徑r為6.0 mm〜30 mm。所謂大致直線狀，係指直線部 211之外觀呈直線狀之含義，亦可局部地包含曲部或凹 凸。一般而言直線部211僅為素管。彎曲部2〗2係於直線部 211間連續地形成之彎曲部分。本例中，彎曲部212為丨8〇 度之彎曲。又，彎曲部212如圖4所示，剖面形成為具有長 轴與短軸之大致橢圓形狀，當將其長軸外徑設為R,、將短 軸外徑設為R時’滿足R/R，S〇.8之關係。亦即，長軸外徑 R’一般而言係與直線部211之外徑r大致相同之長度。 於玻璃管21之内部塗佈有主要由rgb之3波長榮光體而 構成之發光層22。本實施形態中，利用直線部211與弯曲 部212使發光層22之狀態發生變化。其詳細情況將示於圖5 136657.doc 200947502 中。圖5係各部分之玻璃管壁附近之利用SEM(ScanningBACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp used as a light source used in a liquid crystal display device or the like, or a light source of a display device such as a small display device. [Prior Art] A discharge lamp used as a backlight source or the like for a liquid crystal display device is configured as follows: A discharge tube in which a cylindrical or plate-shaped discharge electrode is provided as an electrode on an inner surface of a glass tube coated with a phosphor In addition, a rare gas such as mercury or helium/argon is sealed, and the phosphor is excited by ultraviolet rays generated inside the arc tube by discharge from the discharge electrode to obtain visible light (Patent Document 1). Further, when used as a backlight source or the like as described above, a plurality of discharge lamps are usually used. However, in order to reduce the number of lamps used, an attempt has been made to bend a single glass tube into a U shape. In the L-shaped or U-shaped type, the number of glass tubes per unit area is substantially increased by a smaller number of glass tubes (Patent Document 1 and Patent Document 2). On the other hand, a single glass tube is formed by bending as described above. In the case of a curved discharge lamp such as a word, it is desirable for the operator to arrange the bent portion in the light-emitting region. The purpose is to effectively utilize the light of the curved portion, narrow edge, and the like. However, when the above configuration is formed, the overall luminance in the above-mentioned light-emitting region is uneasy, and unevenness in shell-likeness occurs, and stable light-emitting characteristics cannot be exhibited. [Patent Document 1] Japanese Patent Application Laid-Open No. Hei No. Hei No. Hei No. Hei No. Hei No. Hei No. Hei No. Hei No. Hei No. Hei No. Hei No. Hei No. A discharge lamp for a display device capable of suppressing unevenness in brightness in a light-emitting region of a display device and a backlight device using the same can be disposed even in a state where the bent portion is located in the opening portion. [Means for Solving the Problems] In order to solve the above problems, a discharge lamp for a display device according to the present invention is characterized in that it comprises a glass tube having at least two straight lines. a portion and a curved portion formed between the straight portions; a light-emitting layer containing a phosphor formed on an inner wall surface of the glass tube; and a discharge electrode disposed on the glass tube; wherein the curved portion is a cross section When the outer diameter of the major axis is R and the outer diameter of the minor axis is R, R/R is 0.S. [Effects of the Invention] According to the above aspect, even if the lamp ′ is disposed such that the bent portion is located in the opening, the unevenness in brightness in the light-emitting region of the display device can be suppressed. [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a schematic configuration diagram showing an example of a backlight device of the present invention, and Fig. 2 is a schematic configuration diagram showing an example of a discharge lamp of the present invention. As shown in Fig. 1, the backlight device of this example as an example of a display device includes a casing 1, a plurality of discharge lamps 2, and an optical face material 3. The outer casing 1 is composed of, for example, white plastic, and is composed of a front outer casing 11 and a rear outer casing 12. The front outer casing 11 constitutes a portion of the cover of the outer casing 1, and an opening portion 111 as a light-emitting region in the present backlight device is formed on the main surface. The rear casing 136657.doc 200947502 / is a portion constituting the casing of the casing 1 and is formed in a bottomed opening shape. The inner wall surface of the rear outer casing 12 is highly reflective by a reflection sheet or silver vapor deposition. As shown in Fig. 2, the discharge lamp 2 is a hot cathode fluorescent lamp, and has a glass tube 21 composed of soft glass such as soda lime glass as a main portion. The glass tube 21 is composed of a straight line 4 211, a curved portion 212, and a shrink seal portion 2丨3, and the whole of the discharge lamp 2 is as shown in FIG. 3, and the curved portion 212 is located within the opening 4111, and The staggered shape, that is, the adjacent curved portions 22 are placed alternately in the vertical direction and are arranged side by side in the outer casing 1. Further, in this example, the number of the discharge lamps 2 is four, but it is not limited to this number, and may be set to any number as needed. The linear portion 211 is a portion extending substantially linearly inside the glass tube 21. In this example, the two straight portions 211 are located in parallel in each of the glass tubes 21, and have an outer diameter r of 6.0 mm to 30 mm. The term "substantially straight" means that the straight portion 211 has a linear appearance, and may partially include a curved portion or a concave portion. In general, the straight portion 211 is only a plain tube. The curved portion 2 is a curved portion continuously formed between the straight portions 211. In this example, the curved portion 212 is a curvature of 8 degrees. Further, as shown in FIG. 4, the curved portion 212 is formed in a substantially elliptical shape having a major axis and a minor axis, and when the major axis outer diameter is R and the minor axis outer diameter is R, 'satisfying R/ R, S〇.8 relationship. That is, the major axis outer diameter R' is generally substantially the same length as the outer diameter r of the straight portion 211. A light-emitting layer 22 mainly composed of a three-wavelength refractory of rgb is applied to the inside of the glass tube 21. In the present embodiment, the state of the light-emitting layer 22 is changed by the linear portion 211 and the curved portion 212. Details of this will be shown in Figure 5 136657.doc 200947502. Figure 5 is a SEM (Scanning) near the glass tube wall of each part.
Electron Microscope ’掃描式電子顯微鏡）所拍攝之刮面照 片，拍攝部位於圖5A中係圖2所示之直線部211之又地點， 圖5B中係彎曲部212之Y地點。 根據圖5可知，於直線部211中，螢光體221為稀疏地分 散之狀態，而於彎曲部212中，螢光體221發生凝集，且成 為形成有一些凝集螢光體221，之狀態.然而，並未全部為 ❹ 凝集螢光體221'，亦存在尚未凝集之單體之螢光體221。而 且，虽將直線部211之螢光體22 1之中心粒徑設為τ、將彎 曲邛212之凝集螢光體221'之中心粒徑設為τ，時，滿足 T'/Tg 2.G之㈣。此處’所謂「凝#螢光體」，係指兩個 以上之螢光體發生凝集，而形成為如一個塊體之狀態的螢 光體。 上述凝集螢光體221，，藉由使發光層22含有例如（Ca、 Ba、Sr)〇、BZP4等硼系之黏合劑即硼酸鹽系之黏合劑 φ 222，而可比較容易地形成。其係利用了硼酸鹽系之黏合 齊J 222炫融溫度較低之特性。例如，本例之玻璃管21於 8〇〇°c左右便軟化，而硼酸鹽系之黏合劑於比8〇(rc低之溫 度、例如700t以下熔融。即，若使用硼酸鹽系之黏合劑 222 ’則當為了形成彎曲部212而使玻璃管21加熱軟化時， 黏合劑222亦熔融，藉此使螢光體粒子彼此黏合、凝集’ 從而可於彎曲部212形成凝集螢光體221ι。 黏合劑中除了具有硼酸鹽系以外亦具有Ca2p2〇7等焦磷 酸鹽（pyrophosphate)系等，但使用此種黏合劑之情形時無 136657.doc 200947502 法於彎曲部之形成時形成凝集螢光體。再者，硼酸鹽系之 黏合劑222於直線部211中，如圖5A所示，係存在於玻璃管 21之管壁周邊，而於彎曲部212中則較多地存在於凝集螢 光體22Γ之内部。 又，玻璃管21之内部封入有水銀及氖/氬等稀有氣體。 進而，於其兩端密封有導出至玻璃管21之内外之導線 忒導線23之前端保持有由例如鎢構成之放電電極24。 此處，對本例之放電燈2之一製造方法進行說明。 首先，於直管狀之玻璃管21之内壁面形成發光層22。然 後，藉由燃燒器使玻璃管21之彎曲部212之形成預定部分 加熱軟化，一方面使氮喷入玻璃管21内一方面使其彎曲 1 8 0而形成彎曲部212。此時，較理想的是使彎曲部212之 内周中心Ο比外周中心〇|更向彎曲部212側偏移，且將相對 於直線部211之外徑!*的彎曲部212之外徑R調整為〇 3〜〇 7 倍。其原因在於，為了抑制由於彎曲部212之外周過長而 該部分之壁厚變小所造成的強度降低。再者，彎曲部21 2 之外周侧之壁厚較佳為0.3 mm以上。 繼而’使兩端收縮密封，並經由形成於收縮密封部附近 之排氣管（未圖示），而進行燈内部之脫氣、氣體封入，然 後藉由取走排氣管而可製造放電燈2。 此處’長軸外徑R'與短軸外徑R之關係R/R，，可藉由如 下而進行調整，即，變更内周中心〇與外周中心〇,之關係 或變更彎曲部212之加熱條件、噴氮之條件等，而改變R 值。又，螢光體221之中心粒徑T與凝集螢光體之21，之中心 136657.doc • 10- 200947502 粒徑Τ’之關係τ’/Τ ’可藉由如下而進行調整，即，變更黏 合劑222之添加量或彎曲部212之加熱條件等條件，而改變 凝集螢光體221，之粒徑。 開口部111配置有光學面材3。光學面材3可使用由透明 材料（玻璃、樹脂等）所構成之板、擴散板等。又，於光學 面材3之上亦可進而配置擴散片、稜鏡片、偏光片等各種 光學片。 ❹ 以下表示本例之放電燈之一實施例。再者，直線部211 與f曲部212之螢光體之中心粒徑係藉由粒度分布計而測 定者。 (彎曲部） 長軸外徑R，=15.5 mm、短軸外徑r=9.3 mm， .·. R/R’=〇.6， (螢光體） 紅色螢光體=Y2〇3 : Eu3 + (YOX)，中心粒徑=5 3 μηι，綠色 _ 螢光體=LaP〇4 : Ce3+ ’ Tb3+(LAP)，中心粒徑=8.4 μπι ,藍 色螢光體=BaMg2Al10O17 : Eu2 + (ΒΑΜ)，中心粒揑=6·〇 ，螢光體比率=Υ0Χ ·· LAp : ΒΑΜ=2 ·· 3 · 4，直線部 211之螢光體221之中心粒徑τ=6.64 μπι，彎曲部212之疑集 螢光體22Γ之中心粒徑T'=2〇 ， .·. TVT=3.〇 1。 圖6表示對關於本實施例之燈之亮度分布進行測定之結 果。再者，亮度分布係藉由分光放射亮度計對玻璃管表面 之管軸方向進行測定而獲得者。 136657.doc -11 - 200947502 根據圖6可知，實施例之燈中，作為圖1之直線部211之 ①及③與作為彎曲部212之②中，產生了明顯之亮度差。具 體而言，相對於直線部211之亮度的彎曲部212之相對亮度 較低，為80%左右。 此處，於燈本身以裸露狀態進行照明、例如電性支架般 之用途中’較理想的是彎曲部212之亮度亦較高，從而上 述亮度分布並不理想，而於背光裝置等之用途中，可知上 述亮度分布較為理想。即’只要係實施例之亮度分布之 燈，則即便以使彎曲部212位於開口部111内之方式配置 燈’於背光裝置之發光區域内直線部211與彎曲部212之亮 度之差亦會減少’從而可實現亮度不均得到抑制之背光裝 置。 其次，進行如下實驗，即’對使彎曲部212之長轴外徑 R與短轴外徑R之關係R/R_'、及螢光體221之中心粒徑τ與 凝集螢光體221'之中心粒徑T，之關係T7T變化時的背光裝 置之發光區域之亮度不均進行測定。將結果示於圖7中。 此處’圖中之判定係藉由對點燈中之背光裝置之發光區域 進行目測而進行判斷者，X表示彎曲部看上去明顯亮度不 均之狀態，△表示雖比X有所改善但看上去仍亮度不均之 狀態，〇表示未感到彎曲部有亮度不均之狀態，◎表示幾 乎無亮度不均之狀態。 根據結果可知，R/R'越小則不均越得以改善。認為其原 因在於，R/R’越小’則自彎曲部212之長軸外徑側射出之 光越減少（相反’自短軸外徑側射出之光增加）。另一方 136657.doc -12· 200947502 面’ τ’/τ越大則不均越得以改善。認為其原因在於，凝集 螢光體221之總表面積與凝集前之各個螢光體221之總表面 積相比有所減少，藉此彎曲部212之可見光之生成量減 少。 又，根據結果可知，為了使背光裝置之發光區域之不均 消失較好的疋將R/R'設為較佳之範圍，具體而言，較理 想的是設為0.8以下，更好的是滿足〇 7以下。然而，若 R/R過小，則會產生點燈過程中彎曲部内部之陽極區發生 收縮、從而起動電壓變高等不良，因此較理想的是 R/R’g 0,4。 又，較好的是T7T為2.0以上，更好的是滿足25以上。 較好的疋滿足R/R’S 0.7之關係。然而，若使τ，/τ變得過 大’則會產生螢光體剝離等問題，因此較理想的是相對於 直線部之螢光體之中心粒徑，為4.0倍以下。 再者’如上所述’兩者之構成均係，越對不均有效則製 ie方面或特性方面之不良越谷易發生，因此最佳為將r/r, 與TVT巧妙級合，使不均不易發生，且在無該些不良問題 之範圍内實施。因此，本例中，對於彎曲部212而言，其 剖面為大致橢圓狀，當將長軸外徑設為R，、將短轴外徑設 為R時，R/R，S0.8，藉此’可提供如下顯示裝置用之故電 燈’即’即便以使彎曲部211位於背光裝置之開口部u1r 之方式來配置放電燈2’以發光區域内亮度不均為不明顯 之程度，可使相對於直線部211之彎曲部212之相對亮度降 低0 136657.doc -13- 200947502 又，彎曲部212上形成有螢光體22丨凝集而成之凝集螢光 體22Γ ’當將直線部211之螢光體221之中心粒徑設為T、 將彎曲部212之凝集螢光體221'之中心粒徑設為T，時， T’/T22_0，藉此，與上述相同，可使發光區域内亮度不均 變得不明顯，並且藉由與上述構成之組合而於不易產生不 良之範圍内獲得該效果。 進而’發光層22含有硼酸鹽系之黏合劑222，藉此可於The scratched photograph taken by the Electron Microscope 'Scanning Electron Microscope" is located at a further position of the straight portion 211 shown in Fig. 2 in Fig. 5A, and is the Y point of the curved portion 212 in Fig. 5B. As can be seen from Fig. 5, in the linear portion 211, the phosphor 221 is in a state of being sparsely dispersed, and in the curved portion 212, the phosphor 221 is agglomerated, and a state in which some of the agglomerated phosphors 221 are formed is formed. However, not all of them are agglomerated phosphors 221', and there are also phosphors 221 of monomers which have not been aggregated. Further, when the central particle diameter of the phosphor 22 1 of the linear portion 211 is τ and the central particle diameter of the agglomerated phosphor 221 ′ of the curved crucible 212 is τ, T'/Tg 2.G is satisfied. (4). Here, the term "condensation" refers to a phosphor in which two or more phosphors are aggregated to form a state as a block. The aggregating phosphor 221 can be formed relatively easily by including the boric acid-based binder φ 222 which is a boron-based binder such as (Ca, Ba, Sr) or BZP4. It utilizes the characteristics of the borate-based bonding and the lower temperature of the J 222. For example, the glass tube 21 of this example is softened at about 8 ° C, and the borate-based adhesive is melted at a temperature lower than 8 〇 (rc, for example, 700 t or less. That is, if a borate-based adhesive is used) 222' When the glass tube 21 is heated and softened in order to form the curved portion 212, the adhesive 222 is also melted, whereby the phosphor particles are adhered to each other and aggregated, so that the agglomerated phosphor 221i can be formed in the curved portion 212. In addition to the borate system, the agent also has a pyrophosphate system such as Ca2p2〇7 or the like, but in the case of using such a binder, there is no 136657.doc 200947502 method for forming agglomerated phosphor when the bent portion is formed. Further, the borate-based adhesive 222 is present in the straight portion 211 as shown in Fig. 5A, and is present in the periphery of the tube wall of the glass tube 21, and is present in the curved portion 212 in the agglomerated phosphor 22. Further, a rare gas such as mercury or helium/argon is sealed in the inside of the glass tube 21. Further, a lead wire 23 leading to the inside and the outside of the glass tube 21 is sealed at both ends thereof, and the front end of the lead wire 23 is made of, for example, tungsten. Discharge electrode 24. This A method of manufacturing one of the discharge lamps 2 of the present embodiment will be described. First, the light-emitting layer 22 is formed on the inner wall surface of the straight tubular glass tube 21. Then, the predetermined portion of the curved portion 212 of the glass tube 21 is heated by the burner. Softening, on the one hand, injecting nitrogen into the glass tube 21, on the one hand, bending it 180 to form a curved portion 212. At this time, it is preferable to bend the inner circumference center of the curved portion 212 more than the outer center center 〇| The portion 212 is offset, and the outer diameter R of the curved portion 212 with respect to the outer diameter!* of the straight portion 211 is adjusted to be 〇3 to 〇7 times. This is because the outer circumference of the curved portion 212 is excessively long. Further, the strength of the portion is reduced by the thickness of the portion. Further, the thickness of the outer peripheral side of the curved portion 21 2 is preferably 0.3 mm or more. Then, the both ends are shrink-sealed and formed via the vicinity of the shrink seal portion. An exhaust pipe (not shown) performs degassing and gas sealing inside the lamp, and then the discharge lamp 2 can be manufactured by taking the exhaust pipe. Here, the long axis outer diameter R' and the short axis outer diameter R The relationship R/R, can be adjusted by, ie, within the change The relationship between the center 〇 and the peripheral center 或, or changing the heating condition of the curved portion 212, the condition of nitriding, etc., changes the R value. Further, the center particle diameter T of the phosphor 221 and the center of the agglomerated phosphor 21 136657.doc • 10-200947502 The relationship λ'/Τ' of the particle size Τ' can be adjusted by changing the amount of the adhesive 222 added or the heating condition of the curved portion 212 to change the agglutination fluorescence. The particle size of the body 221. The optical surface material 3 is disposed in the opening portion 111. A plate made of a transparent material (glass, resin, or the like), a diffusion plate, or the like can be used as the optical surface material 3. Further, various optical sheets such as a diffusion sheet, a cymbal sheet, and a polarizer may be further disposed on the optical surface material 3. ❹ An embodiment of the discharge lamp of this example is shown below. Further, the central particle diameters of the phosphors of the linear portion 211 and the f curved portion 212 are measured by a particle size distribution meter. (bending part) Long-axis outer diameter R, = 15.5 mm, short-axis outer diameter r=9.3 mm, .·. R/R'=〇.6, (phosphor) Red phosphor = Y2〇3 : Eu3 + (YOX), center particle size = 5 3 μηι, green _ phosphor = LaP〇4 : Ce3+ ' Tb3 + (LAP), center particle size = 8.4 μπι, blue phosphor = BaMg2Al10O17 : Eu2 + (ΒΑΜ) , Center particle pinch=6·〇, phosphor ratio=Υ0Χ ·· LAp : ΒΑΜ=2 ······························ The center particle diameter of the fluorescent body 22Γ is T'=2〇, .·. TVT=3.〇1. Fig. 6 shows the results of measuring the luminance distribution of the lamp of the present embodiment. Further, the luminance distribution was obtained by measuring the tube axis direction of the surface of the glass tube by a spectroradiometer. 136657.doc -11 - 200947502 As can be seen from Fig. 6, in the lamp of the embodiment, a significant difference in luminance occurs between 1 and 3 of the straight portion 211 of Fig. 1 and 2 as the curved portion 212. Specifically, the relative brightness of the curved portion 212 with respect to the brightness of the straight portion 211 is low, which is about 80%. Here, in the case where the lamp itself is illuminated in a bare state, for example, in an electrical stand, it is preferable that the brightness of the curved portion 212 is also high, so that the above-described brightness distribution is not ideal, and is used in a backlight device or the like. It can be seen that the above luminance distribution is ideal. That is, as long as the lamp of the brightness distribution of the embodiment is provided, even if the lamp portion is placed in the opening portion 111, the difference between the brightness of the straight portion 211 and the curved portion 212 in the light-emitting region of the backlight device is reduced. 'Therefore, a backlight device in which uneven brightness is suppressed can be realized. Next, an experiment was performed to 'resolve the relationship R/R_' between the major axis outer diameter R of the curved portion 212 and the minor axis outer diameter R, and the central particle diameter τ of the phosphor 221 and the agglomerated phosphor 221'. The central particle diameter T is measured as the luminance unevenness of the light-emitting region of the backlight device when the T7T changes. The results are shown in Fig. 7. Here, the judgment in the figure is judged by visually detecting the light-emitting area of the backlight device in the lighting, X indicates a state in which the curved portion appears to be uneven in brightness, and Δ indicates that although it is improved than X, it is seen. In the state where the brightness is not uniform, 〇 indicates that the curved portion has no brightness unevenness, and ◎ indicates that there is almost no brightness unevenness. According to the results, the smaller the R/R', the more the unevenness is improved. The reason is considered to be that the smaller the R/R' is, the more the light emitted from the long-axis outer diameter side of the curved portion 212 is decreased (oppositely, the light emitted from the short-axis outer diameter side is increased). The other side 136657.doc -12· 200947502 The larger the face τ'/τ, the more the unevenness is improved. The reason for this is considered to be that the total surface area of the aggregated phosphor 221 is reduced as compared with the total surface area of each of the phosphors 221 before aggregation, whereby the amount of visible light generated by the curved portion 212 is reduced. Further, as a result, it is understood that R/R' is preferably in a preferable range in order to make the unevenness of the light-emitting region of the backlight device disappear, and specifically, it is preferably 0.8 or less, and more preferably satisfies 〇7 or less. However, if R/R is too small, there is a problem that the anode region inside the bent portion shrinks during the lighting process, and the starting voltage becomes high. Therefore, R/R'g 0, 4 is preferable. Further, it is preferred that T7T is 2.0 or more, and more preferably 25 or more. A better enthalpy satisfies the relationship of R/R'S 0.7. However, if τ and /τ are excessively large, problems such as peeling of the phosphor are caused. Therefore, it is preferable that the center particle diameter of the phosphor with respect to the straight portion is 4.0 times or less. Furthermore, as described above, the composition of both is the same, and the more effective the unevenness is, the worse the IE aspect or the characteristic is. Therefore, it is best to combine r/r with TVT to make the unevenness It is not easy to occur and is implemented without such adverse problems. Therefore, in this example, the curved portion 212 has a substantially elliptical cross section, and when the outer diameter of the major axis is R and the outer diameter of the minor axis is R, R/R, S0.8, This can provide a lamp for the display device, that is, even if the bending portion 211 is placed in the opening portion u1r of the backlight device, the discharge lamp 2' can be disposed such that the brightness in the light-emitting region is not inconspicuous. The relative luminance of the curved portion 212 with respect to the straight portion 211 is lowered. 136657.doc -13- 200947502 Further, the curved portion 212 is formed with the agglomerated phosphor 22 of the fluorescent body 22, and the linear portion 211 is formed. When the center particle diameter of the phosphor 221 is T and the center particle diameter of the aggregated phosphor 221' of the curved portion 212 is T, T'/T22_0, in the same manner as described above, the light-emitting region can be made. The unevenness in brightness becomes inconspicuous, and this effect is obtained in a range in which the defect is less likely to occur by the combination with the above configuration. Further, the light-emitting layer 22 contains a borate-based adhesive 222, whereby
彎曲部212之加熱軟化步驟時形成彎曲部212之凝集螢光體 22Γ。 再者，本發明係對薄型顯示裝置尤其有效之發明，該薄 型顯示裝置於如放電燈2與光學面材3之距離為1〇 mm以下 之於發光區域内放電燈2之明暗容易產生。 以上，係根據上述實施形態對本發明進行了詳細說明， 但本發明並不限於上述實施形態，只要不脫離本發明之範 則可進行各種變形或變更。The agglomerated phosphor 22 of the curved portion 212 is formed in the heating softening step of the curved portion 212. Further, the present invention is particularly effective for a thin display device which is easy to generate light and darkness of the discharge lamp 2 in a light-emitting region when the distance between the discharge lamp 2 and the optical face material 3 is 1 〇 mm or less. The present invention has been described in detail above with reference to the embodiments. However, the invention is not limited thereto, and various modifications and changes can be made without departing from the scope of the invention.
本例中，係使用熱陰極螢光燈作為放電燈2，亦可為 陰極螢光燈、外面電極螢光燈等之燈。 又，放電燈2係具有兩個直線部2112u字管，但亦可 具有三個直線部211之〕字管或s字管、具有四個直線 211之W字管或正方形管等。 又，彎曲部212之彎曲不限於18〇度，亦可為似、⑽ 等二又，本例中，形成為使4娜字放電燈之以交錯狀仏 配设之構成’但配設數量或配設方向可視需要而任意地〗 定。例如，亦可單獨地使用放電燈2，或使用⑽以上，; 136657.doc -14* 200947502 全部配設於相同方向。 【圖式簡單說明】 圖1係表示本發明之背光裝置之一例之概略圖。 圖2係表示本發明之放電燈之一例之概略圖。 圖3係表示圖1所示之背光裝置之俯視平面圖。 圖4係將圖1所示之放電燈之彎曲部之剖面放大表示之 圖。 圖5(a)圖5(b)係各部分之玻璃管壁附近之利用sem(電 子顯微鏡）所獲得之剖面圖。 圖6係相對地表示放電燈之各部位之亮度之圖。 圖7係關於使彎曲部之長轴外徑與短軸外徑之比R/R，及 相對於直線部之螢光體之中心粒徑的彎曲部之凝集螢光體 之中心粒徑變化時之背光裝置之發光區域的亮度不均之說 明圖。 【主要元件符號說明】 1 外殼 2 放電燈 3 光學面材 11 外殼 12 後外殼 21 玻璃管 22 發光層 23 導線 24 放電電極 136657.doc ❹ 200947502 111 開口部 211 直線部 212 彎曲部 213 收縮密封部 221 螢光體 221' 凝集螢光體 222 黏合劑 Ο 内周中心 O' 外周中心 r 直線部之外徑 R 短軸外徑 R, 長軸外徑 T、Τ' 中心粒徑 X、Y 地點 136657.doc 16-In this example, a hot cathode fluorescent lamp is used as the discharge lamp 2, and it may be a lamp such as a cathode fluorescent lamp or an external electrode fluorescent lamp. Further, the discharge lamp 2 has two straight portions of a 2112u word tube, but may have a word tube or a s-shaped tube of three straight portions 211, a W-shaped tube having four straight lines 211, a square tube, or the like. Further, the bending of the curved portion 212 is not limited to 18 degrees, and may be similar to (10) and the like. In this example, the four-shaped discharge lamp is formed in a staggered configuration, but the number or The direction of the arrangement can be arbitrarily determined as needed. For example, the discharge lamp 2 may be used alone, or (10) or more may be used; 136657.doc -14* 200947502 are all disposed in the same direction. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing an example of a backlight device of the present invention. Fig. 2 is a schematic view showing an example of a discharge lamp of the present invention. 3 is a top plan view showing the backlight device shown in FIG. 1. Fig. 4 is an enlarged cross-sectional view showing a bent portion of the discharge lamp shown in Fig. 1. Fig. 5(a) and Fig. 5(b) are cross-sectional views obtained by sem (electron microscopy) in the vicinity of the glass tube wall of each part. Fig. 6 is a view showing the relative brightness of each portion of the discharge lamp. 7 is a graph showing a ratio R/R of the major axis outer diameter to the minor axis outer diameter of the curved portion and a central particle diameter of the agglomerated phosphor of the curved portion with respect to the central particle diameter of the phosphor of the straight portion. An illustration of the unevenness in brightness of the light-emitting area of the backlight device. [Description of main components] 1 Housing 2 Discharge lamp 3 Optical surface material 11 Housing 12 Rear housing 21 Glass tube 22 Light-emitting layer 23 Conductor 24 Discharge electrode 136657.doc ❹ 200947502 111 Opening portion 211 Straight portion 212 Curved portion 213 Shrinkage seal portion 221 Phosphor 221' Aggregation phosphor 222 Adhesive Ο Inner circumference center O' Peripheral center r Straight line outer diameter R Short axis outer diameter R, Long axis outer diameter T, Τ' Center particle size X, Y Location 136657. Doc 16-