200903104 九、發明說明： C發明所屬之技術領域3 發明領域 本發明係有關一種具有熱陰極螢光燈之背光源，特別 ' 5 是有關於一種用於大畫面視或看板之背光源。 【先前技術3 發明背景 現在，液晶顯示器之背光單元之光源主要採用冷陰極 螢光燈。冷陰極螢光燈適合進行細徑化，故已使用作為要 10 求薄型化之背光單元之光源（參照諸如專利文獻1)。 【專利文獻1】特開昭56-73855號公報 【發明内容3 發明揭示 發明所欲解決之問題 15 近年，液晶顯示器日漸大型化，背光單元亦隨之逐漸 大型化。因背光單元之大型化，一旦使用冷陰極螢光燈作 I 為光源，則點亮電路將趨於複雜化，且有耗電增加之疑慮。 進而說明之，冷陰極螢光燈與他種光源相較，驅動所 需之電壓（驅動電壓）較大，而須使用高壓電源。尤其，晝面 20 尺寸32吋或更大之大型液晶顯示器（諸如32吋、42吋、46 11寸、65忖或更大之液晶顯示器）近期已上市，燈長度已增 加，而隨之增強了驅動電壓進而高壓化之傾向。 又，冷陰極螢光燈每支所需電力較小，故為確保晝面 亮度而須增加支數，故而，不僅零件成本將提高，且組裝 5 200903104 工時亦增加之問題亦可能更為顯著。 因此，已開始檢討採用效率高於冷陰極螢光燈，點亮 電路亦可簡化之熱陰極螢光燈作為背光單元之光源之可行 性。然而，因研發冷陰極螢光燈作為背光源直至今日仍方 5 興未艾，故實際上尚未克服熱陰極螢光燈之缺點。 本案發明人針對液晶顯示器之大型化所逐漸突顯之背 光單元之問題，並未藉改良目前主流之冷陰極螢光燈而試 圖加以解決，反而嘗試利用熱陰極螢光燈作為解決之方案。 使用熱陰極螢光燈之背光單元與使用冷陰極螢光燈者 10 相較，其產熱量極大。此因與冷陰極螢光燈不同，熱陰極 螢光燈係使用包含可放出熱電子之燈絲之電極之故，而， 此則為對燈絲輸入維持放電電流或熱電子之放出之電力所 致，此外，也因與冷陰極螢光燈相比，熱陰極螢光燈所需 之電力（功率）較大之故。 15 又，液晶顯示器用之背光源與一般照明用之熱陰極螢 光燈相比，宜可達約5倍之較長壽命。此則因既已作為.背光 源使用之冷陰極螢光燈號稱60,000小時之壽命，為確保同 等之壽命，熱陰極螢光燈亦需具備一般照明用者之5倍程度 之壽命之故。因此，為搭載更多發射體，而增長燈絲線圈 20 後，預熱電力亦隨之提高而比一般照明用之熱陰極螢光燈 之產熱量明顯更為提高。結果，研究發現前述大量產熱致 使不耐高溫之液晶顯示部之光學構件劣化而發生對晝質造 成不良影響之問題。隨著近年液晶顯示器之薄型化趨勢， 背光單元内之容積減小，背光源與前述光學構件之距離亦 200903104 縮小，而可預見該問題將更為突顯。 實際之背光單元中，為對應熱陰極螢光燈之產熱問 題，而須裝入風扇之類之散熱構件，但又將使成本提高。 即便如此，一旦將電力供給降低至熱陰極螢光燈之產熱不 5 致對光學構件造成影響之程度，亦將失去熱陰極螢光燈本 身之利基。 本發明即有鑑於以上問題而設計者，其主要目的在提 供一種可於具有熱陰極螢光燈之背光源内以簡易之構造解 決產熱問題之構造。 10 用以欲解決問題之手段 本發明之背光源包含有：熱陰極螢光燈；及，燈座， 用以保持前述熱陰極螢光燈；前述熱陰極螢光燈則包含 有：燈管，内面上形成有螢光體；及，燈絲，設於前述燈 管内，可放出熱電子；前述燈座配設於前述燈絲所存在之 15 燈絲存在領域之前述燈管之外面，且，前述燈座係由金屬 材料所構成。 前述燈絲存在領域宜位在自前述燈絲之中心位置起土 10mm之範圍内。 本發明之另一背光源包含有：熱陰極螢光燈；及，燈 20 座，用以保持前述熱陰極螢光燈；前述熱陰極螢光燈則包 含有：燈管，内面上形成有螢光體；及，燈絲，設於前述 燈管内，可放出熱電子；前述燈座可將燈管之外面保持在 自前述燈絲所存在之處至燈管之端部側之範圍内，且，前 述燈座係由金屬材料所構成。 7 200903104 較佳實施例中，前述燈座完全由金屬材料所構成。 較佳實施例中，前述燈座與前述燈管之間隙内形成有 含有填料之樹脂材料。 較佳實施例中，前述背光源係用於直下型之影像顯示 5 裝置者。 較佳實施例中，前述背光源係用於32吋至46吋之晝面 尺寸之液晶顯示器之光源，前述背光源配置有4支至6支之 前述熱陰極螢光燈。 實施例中，前述背光源由四層線圈所構成。 10 實施例中，前述熱陰極螢光燈係額定壽命2萬小時以上 者。 實施例中，前述熱陰極螢光燈之一支之一對電極中之 一個之前述燈絲上塗布有5.Omg以上之發射體。 實施例中，前述熱陰極螢光燈之前述燈管内之氣壓為 15 500Pa以上。 實施例中，前述熱陰極螢光燈之燈管之截面為圓形。 實施例中，前述熱陰極螢光燈之燈管之截面為略橢圓 形。 發明效果 20 依據本發明之背光源，藉燈座可保持燈絲所存在之燈 絲存在領域之燈管之外面，且，該燈座係由金屬材料所構 成，故即便不使用風扇等散熱構件，與樹脂製之燈座相比， 亦可達到明顯之降溫效果。 圖式簡單說明 200903104 第1圖係說明包含本發明之實施例之背光源1 ο 0之影像 顯示裝置1000之構造之分解立體圖。 第2圖係模式地顯示本發明之實施例之熱陰極螢光燈 10之截面圖。 5 第3圖係顯示本發明之實施例之背光源100之構造之截 面圖。 第4圖係顯示本發明之實施例之背光源100之構造之平 面圖。 第5圖係說明本發明之實施例之燈座7 5之構造之立體 10 圖。 第6(a)、6(b)圖係顯示本發明之實施例之背光源之構造 之平面圖。 第7圖係說明本發明之實施例之燈座75之構造之立體 圖。 15 第8圖係顯示以反射板之溫度[°C]為依據之溫度降低效 果之圖表。 第9(a)、9(b)圖係顯示管轴方向之位置與管面溫度之關 係之圖表。 第10(a)、10(b)圖係顯示管轴方向之位置與管面溫度之 20 關係之圖表。 第11(a)、11(b)圖係顯示管轴方向之位置與管面溫度之 關係之圖表。 第12(a)、12(b)圖係顯示管轴方向之位置與燈内溫度之 關係之圖表。 9 200903104 【實施方式3 用以實施發明之最佳形態 本案發明人未使用目前主流之冷陰極肇光燈叹叩作 為大晝面曰益加速發展之液晶顯示器用之背光源，而考量 5改用與冷陰極螢光燈相比，每支需求較大輪出之電力之熱 陰極螢光燈(HCFL)，進行研究開發。上述改用之理由，則 為藉發揮熱陰極螢光燈之「較大輸出」之特徵以提昇液 晶電視之對比度，並亦使動畫高晝質化，同時與冷陰極榮 光燈相比，作為背光源使用之螢光燈支數可大幅減少，而 1〇 降低成本之故。 然而，使用熱陰極螢光燈之背光源與使用冷陰極勞光 燈之背光源相比，原即存在易形成高溫之本質性問題。背 光源一旦形成高溫，使用於背光源之光學構件（諸如光學膜 片、反射板）多不耐高溫，其等之劣化，則將導致影像顯示 15裝置（液晶顯示裝置)之光學特性、影像特性之劣化。 由上，本案發明人偶然發現，為緩和來自熱陰極螢光 燈之高溫影響，一旦將通常遠離熱陰極螢光燈之燈絲而配 置之燈座勉強移近而配置之，若燈座係由金屬所構成，則 即便不使用散熱構件，亦可使背光源降溫，而完成本發明。 0 以下，參照圖示，說明本發明之實施例。以下之圖示 中，為求簡化說明，以相同之標號代表實質上具備同一機 能之構成要素。另，本發明並不限於以下之實施例。 以下參照第1〜第4圖，說明本發明之實施例之背光源 100。 200903104 第1圖係模式地顯示包含本實施例之背光源100之影像 顯示裝置（液晶顯示裝置）1000之構造之分解立體圖，第2圖 係模式地顯示構成本實施例之背光源100之熱陰極勞光燈 10之截面構造者。第3及第4圖則係分別顯示本實施例之背 5 光源100及影像顯示裝置1000之構造之截面圖及上面圖。 本實施例之背光源1〇〇如第1圖所示，包含有熱陰極螢 光燈10，以及用以保持熱陰極螢光燈10之燈座75。熱陰極 螢光燈10則如第2圖所示，由内面12a上形成有螢光體（未圖 示）之燈管12所構成，燈管12内則設有可放出熱電子之燈絲 10 14。 燈座7 5可保持燈絲14所存在之燈絲存在領域5 5 (未圖 示）之燈管12之外面12b ,且，該燈座75係由金屬材料所構 成。燈絲存在領域55位在諸如由燈絲中心位置i4cs±3〇mm 之範圍内’而以±l〇mm之範圍内為佳。 15 第1圖所示之例中之燈座7 5完全由金屬材料所構成，該 金屬材料則為諸如鋁、黃銅、不銹鋼、鐵（或，經電鍍之鐵） 等。本實施例中，雖使用鋁製之燈座75 ,但即便不使燈座 75完全為金屬製，亦可選擇性地以金屬構成燈絲存在領域 55之部分。又，燈座75之厚度並無特別限制，可為諸如 2〇以上’本實施例之一例中，使用1〜l〇mm厚度之燈座75。另， 燈座75之效果等則留待後述。 本實施例之熱陰極螢光燈10之端部設有管帽5〇。管帽 5〇係由諸如樹脂材料(PET(聚對苯二甲酸乙二醋）、ρΒτ(聚 對苯二甲酸二丁⑹等)或金屬材料⑽等)所構成。另，本實 11 200903104 施例之構造中，管帽50之周圍配置有管座（未圖示），以與管 帽50之外部端子（諸如針銷狀之端子)連接◎管帽5〇之外部端 子則朝諸如與燈管12之長向92略成垂直之方向（諸如屏幕 方向90之反方向）延伸。另，管帽5〇之外部端子亦可沿燈管 5 12之長向92而自管帽50之端面延伸而形成。 以下進而就本實施例之背光源1〇〇所使用之熱陰極螢 光燈10加以說明。本實施例之熱陰極螢光燈1〇使用作為背 光源，故使用壽命較長者。熱陰極螢光燈1〇宜為額定壽命 1.2萬小時以上者，進而，以額定壽命2萬小時或3萬小時以 10上為佳。另，作為顯示器而長久以來廣為使用之CRT(陰極 射線管）之壽命約為20000小時，故宜採用壽命較之更長者。 圖示之熱陰極螢光燈10係由直管狀之玻璃燈管12，以 及配設於玻璃燈管12兩端之一對電極11所構成。 玻璃燈管12係鈉約玻璃製或石夕酸鋇銷（軟化點675之 15 軟質玻璃）製者。玻璃燈管12之大小予以例示，則用於32对 之燈管12外徑12mm、厚0.8mm、長730mm，用於45时之燈 管12外徑12mm，厚0.8mm、長1010mm。用於65忖之燈管 12外徑25.5mm、厚0.8mm、長1499mm。另，用於1〇5对之 燈管12外徑38mm、厚0.9mm、長2367mm。另，燈營之厚 20 度亦可為1.0mm。 玻璃燈管12之内面上塗布有螢光體（未圖示）。更具體而 言，玻璃燈管12之内面12a上，形成有由氧化鋁形成之保護 膜，該保護膜上則積層有螢光體層。構成螢光體層之榮光 體可使用可發光諸如紅(Y2〇3 : Eu)、綠（LaP〇4 : Ce，Tb3)及 12 200903104 藍(BaMg2Al16027 : Eu，Mn)之各色之稀土類螢光體混合而成 者。另，螢光體亦可使用其它稀土類螢光體。舉例言之， 紅色可使用（Y,La)2〇3 : Eu、3.5MgO . 0.5MgF2. Ge〇2: Μη， 綠色可使用 CeMgAlnOw : Tb、GdMgB2O10 : Ce，Tb，藍色 5 可使用(Sr，Ca)10(PO4)6Ci2 : Eu。 燈管12内封入有水銀與惰性氣體。本實施例中，於玻 螭燈管12内，封入有約5mg之水銀(未圖示）’以及作為緩衝 用惰性氣體而在常溫下壓力為500Pa之氬(Ar)。另，封入燈 管12内之水銀除水銀單體以外，亦可在諸如鋅水銀、錫水 10 銀、鉍、銦水銀等水銀合金之形態下加以封入。 又，惰性氣體除氬(Ar)之混合比率為100%者外，亦可 使用對氬(Ar)混合氪(Kr)者。氪(Kr)之混合比（分壓比）為諸 如20%〜60%，例如可為氬：氪=50% : 50%之混合氣體（氣壓 6〇〇Pa) 〇 15 本實施例之電極11係由燈絲14、用以保持燈絲14之一 對導線13、用以保持該對導線13之玻璃珠15所構成。破王离 珠15亦稱為植珠。圖示之電極π係所謂玻璃植珠方式者。 燈絲14係鎢製者，本實施例之構造之一例中，為使_ 壽命延長並增加發射體塗布量而構成複雜之線圈形狀 即’於較粗之鶴線周園寬鬆纏附較細之鎮線而形成長气狀 之構造體，並將該構造體捲成螺旋狀者即稱為二層線圈 燈絲14則為將前述二層線圈再捲成螺旋狀而構成之三 "~~' 線 圈’或將前述三層線圈進而捲成螺旋狀而構成之四猛& w續線 圈。燈絲14為三層線圈時，第三層之線圈係5〜7圈之電極線 13 200903104 圈。又，燈絲14為四層線圈時，則為2〜4圈之電極線圈。 塗布於燈絲14之發射體係諸如锶、鈣' 鋇之氧化物。 本實施例中’為使燈壽命延長，而增加塗布於燈絲14之發 射體量’本實施例中，已就各熱陰極螢光燈1〇，在一對電 5極中之一之燈絲Η上塗布5.0mg以上之發射體。另，惰性氣 體之構成亦非使用100%氬，而以預定混合比混入原子量大 於氬之氪’以使發射體難以自燈絲14飛散，技術上而言可 延長燈壽命。 圖示之電極11挾封於玻璃燈管12之密封部16。又，玻 10璃燈管12之至少一端部封接有排氣管17。該排氣管17使用 於自燈管12内排氣或封入惰性氣體時，係於上述排氣、封 入後封接者。另，若不僅於燈管12之一端而於兩端設置排 氣管17，則有可有效進行排氣、氣體封入之優點。又，藉 此’亦可降低燈管12内部之雜質比例。 15 玻璃燈管12之端部設有管帽50以覆蓋密封部16及排氣 管Π。另，自密封部16朝外延伸之導線13之延長部18與管 帽50之線接方法，可配合螢光燈1〇之規格而適當加以決 定。具體而言，形成於管帽50上之外部端子（諸如針銷）可與 導線13之延長部18電性連接。管帽5〇之外部端子（未圖示） 20 則與管座（未圖示）相連接。 如第1、第3及第4圖所示，包含熱陰極螢光燈1〇之背光 源100裝設於影像顯示裝置1〇〇〇内，本實施例之背光源^0 係用於直下型之影像顯示裝置之背光源。此外，背光源100 可使用作為諸如26吋以上（宜為32吋以上。諸如32吋、40 14 200903104 吋、42吋、46吋、65吋等）之液晶顯示器用之面狀光源。另， 第1圖中，雖未顯示液晶面板6〇，但第3圖中顯示有液晶面 板。 圖示之例中，例示了配置6支熱陰極螢光燈1〇。然而， 5熱陰極螢光燈1〇之支數並不限於該數。另，本實施例之較 佳之一例中，對於32吋至46吋之畫面尺寸之液晶顯示器之 面板，配置4支至6支之熱陰極螢光燈1〇，而可進行點亮、 動作。又，燈座75可為用以保持全部螢光燈1〇(本例中為6 支）之構造者，亦可為用以保持各丨支螢光燈1〇之構造，或 10 各保持複數支(諸如2支或3支)之構造者。 用以容置本實施例之背光源1〇〇之箱體之一部分之反 射板21係由金屬板（諸如經電鍍之鐵製品或鋁製品）所構 成’其厚度l_5mm。圖示之例中，反射板2丨之一部分彎曲 成凸狀（三角狀），而構成輔助反射板22。包含輔助反射板22 15之反射板21之上面（箱體之主面20b)則形成有反射片23。反 射片23係由白色之氧化鈦（或碳酸鈣）分散而成之聚對笨二 曱酸乙一自曰（PET)之樹脂層所構成，其厚度2.〇mm。輔助反 射板22之頂點（或稜線）之一部分則形成有用以支持光學膜 片30之下面之支柱24。支柱24係白色樹脂製者。另，第3圖 20所示之背光源之高度Η(自反射板21之上面至光學膜片 3〇所位在之面為止之高度）為諸如27mm。 又，如第3圖所示，背光源1〇〇之反射板21之下方可配 設點亮電路(安定器電路或安定器）70。本例中，就各螢光燈 10設有—點亮電路70，故而，就6支螢光燈10使用6個點亮 15 200903104 電路70。但’點亮電路7G與Μ㈣之數量亦可不同。 點亮電路70經管帽50而與螢光燈1〇電性連接，又，亦 具有調光機能。於反射板21之下設有下罩72， 電路7〇。下罩72係由厚！·5職之金屬板所構成。^罩: 5反射板21之間之空間内配設有諸如配線。另，背光源刚亦 可不設下罩72,此時點亮電路7〇亦可先配置於液晶顯示器 (諸如液晶電視)之箱體内。 又’如第4圖所示，反射板21之端部設有上述之燈座 〜本例中，光學膜片3〇由上依序包含有偏向片31(住友3μ 10 公司製 DBEF(Dual Brightness Enhancement Fiim)，厚 〇.440mm)、透鏡片 32(厚G155mm)、擴散片 33(厚G n3mm)、 擴散板34(厚2.Gmm)。擴散板34之下面亦可進而設置透鏡 片。 15 進而，在光學㈣3G上，配設有液晶Φ板（諸如厚約 15 2職)6G ’又，亦配設有上祕以覆蓋該液晶面板⑼及光學 臈片30。上罩62係由諸如厚15麵之金屬板所構成。另， ^例之影像顯示領域65(參照第4圖）為1〇18_573匪，但 以不限於§亥尺寸，亦可為其它尺寸。又，發光燈之密 2〇封部16周邊作為邊框領域而被覆蓋，以遮蔽螢光燈10之非 點冗部位，該非點亮部位即不致外顯。另由背光源加 X觀察，液晶面板60所位在之方向即屏幕方向9〇。 其次，參照第5圖，&而說明本實施例之熱陰極螢光燈 及燈座7S第5圖係說明熱陰極榮光燈1〇與燈座％之立體 圖。 16 200903104 如上所述，本實施例之燈座75可藉保持燈絲14所存在 之燈絲存在領域55之燈管12之外面，而保持螢光燈仞，且， 該燈座75非由絕緣材料(特別是樹脂)所構成，而係由金屬材 料所構成。 10 15 20 以下，與目前主流之冷陰極螢光燈(CCFL)對比而進行 說明。冷陰極螢光燈驅動所需之電壓（驅動電壓）較大，為其 特徵。因此，螢紐之電錄抗較大，料若有金屬則將 發生電/VIL外漏。遠電流外漏之發生將導致螢光燈之軸内之 亮度不均及之降低’喊問題。因此，即便使用燈^ 以保持冷陰極榮光燈，亦僅可使用樹脂(絕緣材料)製品。 冷陰極榮光燈之燈電壓較高之原因如下。冷卜^勞光 燈於玻璃燈管之㈣上”㈣総，並狀^為緩衝 孔體之惰性氣體(Ne或Ar)與適量之水銀。電極係由錄等金 屬形成筒狀而裝設，對電極間施加高電壓即可發生放電。 冷陰極螢紐與謎㈣紐不同，縣自f極放出執電 子，而由電極供給電子故需要極高之陰極效果電壓 (100〜200V程度)(熱陰極螢光燈則為1〇v左右）。進而，冷陰 極發光燈之时絲細，且社t性㈣鼓，故轉2 落差電壓之高歧相影響而形成較高之管電壓（燈電壓）。因 此，需要上述較高之電壓之發光燈之燈座極難以使用導電 性材料(金屬材料）。 另，熱陰極榮光燈與冷陰極榮光燈相較，具有產孰量 極大之特徵。此_熱陰極螢光燈與冷陰極螢光燈不同， 其使用包含可放ώΜ子之燈狀電極，且與冷陰極勞光 17 200903104 燈相較，熱陰極螢光燈所需之電力（功率）較大之故。 使用上述產熱較大之熱陰極螢光燈時，其燈座為避免 熱之影響，而宜遠離熱陰極螢光燈之燈絲而配置。此則因 燈絲附近之高溫領域若配置有燈座，則可能容易使燈座變 5 形。 本案發明人以金屬製品取代典型之樹脂製品構成燈 座，並加以配置於通常不予配置之燈絲附近，在該實驗時 偶然發現背光源之降溫效果。其降溫可達與用風扇等冷卻 方法相當之顯著效果。 10 參照第6〜第8圖說明該降溫效果。本案發明人準備金屬 製之燈座75與熱陰極螢光燈1〇之套組，並進行實驗測定其 溫度。使用之熱陰極螢光燈10之燈管12係截面略橢圓形 者，又，燈絲14則使用方向為縱置者與橫置者而加以觀察。 第6(a)圖係燈絲14縱置之熱陰極螢光燈1〇，第6(b)圖所示者 15 則為燈絲14橫置之熱陰極螢光燈1〇。 另，第6(a)圖中之管帽50處標示有與燈管12之長向垂直 延伸之針銷（外部端子）51。針銷51若朝管帽5〇之側面方向延 伸，則可使窄邊框（即’屏幕顯示領域外之緣部）之設計更為 容易。 20 第6(a)圖所示之熱陰極螢光燈10之構造若以第5圖之立 體圖加以顯示，則將如第7圖。惟，第6(a)圖及第6(b)圖所 示之構造，係使燈座75與燈絲中心位置i4c錯開距離 L2(8mm)，燈座75並使用厚度較薄（本例中為imm)之銘製之 燈座。另，燈座75之外緣(基準線）至外側之長度L1(邊框長， 18 200903104 即非顯示面）為3〇mm。又，與第6⑻圖相同之構造(燈絲橫 置)則準備樹脂製之燈座，而以之為比較例（參考基準)進行 測定。 結果顯示於第8圖。第8圖係顯示對背光源裝設第以及 5第6(b)圖所示之構造’即’略燈管12之榮光燈，而進 行^度測定之結果之圖表。另，第8圖中之縱軸代表反射板 之溫度rc]，橫軸代表業經調光後之系統輸入電力間。系 、统輸入電力[W]為130W左右時，代表實驗所使用之背光源 Duty比大致之調光狀態，娜左右則代表_比為 10 40%或更低之調光狀態。另，該調光之控制係藉p雙控制 改變電力而進行。 如第8圖所示，在Duty比為4〇%以上之範圍内，比較比 較例（樹脂製燈座）之線(C)，與金屬製燈座之線(A)及(B)， 則可發現約20 C之降溫效果，在Duty比未滿4〇%之範圍 15内’亦發現約25〜抓之降溫效果。另，第8圖巾之線㈧ 【 及㊉)分別對應第6(a)及第6(b)圖之形態。對應第6(a)及第6(b) 圖之線(A)及(B)之結果大致相同，故推論即便使用截面圓形 之燈管12之熱陰極螢光燈10，結果亦將與其等相同。 未使用冷卻扇等構件，即可達到上述之降溫效果，乃 20通常所難以想像。即，通常，為達到某種程度之降溫(諸如 ίοc或更大幅度之降溫)效果，不得不採用冷卻扇等專用構 件，或捨棄大1燈電力之使用。亦即，無法避免反射板21 及光學膜片30之耐熱性問題，即便欲提昇燈亮度，假設1〇 C之溫度上昇為限制（即設計上之限制條件），則僅得追加冷 19 200903104 卻零件(諸如冷卻扇）、大幅變更背光源之熱設計，或捨棄燈 輸出（亮度)之提昇。 然而，依據本實施例之構造’燈座75採用金屬製品’ 即可達到燈周邊溫度（特別是反射板21與光學膜片30之温 5 度）顯著降低之效果。故而，不致產生新的零件成本及熱設 計開發成本，即可達成降溫效果，將提供莫大之技術貢獻。 又，利用本實施例之構造，即便加入冷卻、散熱機構， 亦可利用本實施例之冷卻效果，故可加入簡便且廉價者， 或’即便改變熱設計，可對應輕微變更之可能性亦將提高。 10 故而，此點亦深具技術價值。 另，除與燈座75之組裝安定性以外，為提昇螢光燈10 之散熱性，於燈管12與燈座75之間隙内亦宜設有包含填料 之樹脂材料77(參照第7圖）。上述樹脂材料77可由含有填料 之聚矽氧片所構成，亦可藉填料之種類而提昇樹脂材料77 15之熱傳導率而提昇散熱性。舉例言之，對樹脂（或由樹脂構 成之彈性體)77添加AGO3、BN、AIN、Si〇2作為無機填料後， 可提昇熱傳導率。又，藉選用適當之無機填料，則可調整 熱膨脹係數。 燈座75採用金屬製品即可降溫之原因，本案發明人之 20考量如下。其可推論係因樹脂製之燈座與金屬製之燈座， 熱傳導率有差別之故。即，可推論相較於樹脂，金屬之熱 傳導率高達諸如1000倍以上，故熱陰極螢光燈1〇之熱尤 其是燈絲存在領域55之熱，可經金屬製之燈座75而傳至背 光源之箱體及空氣中，結果即可顯著提昇散熱效率所致。 20 200903104 第8圖所不之實施例中，已確認金屬製之燈座75之 厚度雖僅有1 ，但如此微小之構件存在，亦可實現相當 於裝汉冷卻4之降溫效果。 /BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight having a hot cathode fluorescent lamp, and in particular, a backlight for a large screen or a viewing panel. [Prior Art 3 Background of the Invention Now, the light source of the backlight unit of the liquid crystal display mainly uses a cold cathode fluorescent lamp. Since the cold cathode fluorescent lamp is suitable for thinning, it has been used as a light source for a backlight unit which is required to be thinned (see, for example, Patent Document 1). [Patent Document 1] JP-A-56-73855 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION In recent years, liquid crystal displays have become larger and larger, and backlight units have gradually increased in size. Due to the increase in size of the backlight unit, once a cold cathode fluorescent lamp is used as the light source, the lighting circuit tends to be complicated, and there is a concern that power consumption increases. Further, the cold cathode fluorescent lamp has a larger voltage (driving voltage) required for driving than other kinds of light sources, and a high voltage power supply is required. In particular, large liquid crystal displays (such as 32-inch, 42-inch, 46-inch, 65-inch or larger liquid crystal displays) with a size of 32 inches or larger have recently been on the market, and the length of the lamps has increased, which has been enhanced. The tendency of the driving voltage to be further increased. In addition, the cold cathode fluorescent lamps require less power per lamp. Therefore, in order to ensure the brightness of the kneading surface, the number of components must be increased. Therefore, not only the cost of parts will be increased, but also the problem of assembly time 200903104 may increase. . Therefore, it has been possible to review the feasibility of using a hot cathode fluorescent lamp whose efficiency is higher than that of a cold cathode fluorescent lamp and a lighting circuit can be simplified as a light source of a backlight unit. However, the development of cold cathode fluorescent lamps as backlights is still in the ascendant today, so the shortcomings of hot cathode fluorescent lamps have not been overcome. The inventors of the present invention have attempted to solve the problem of the backlight unit which is gradually highlighted by the enlargement of the liquid crystal display, and instead attempted to use the hot cathode fluorescent lamp as a solution. The backlight unit using the hot cathode fluorescent lamp has a much higher heat generation than the one using the cold cathode fluorescent lamp. This is different from a cold cathode fluorescent lamp in that an electrode including a filament capable of emitting hot electrons is used, and this is caused by maintaining a discharge current or a discharge of hot electrons to the filament input. In addition, the power (power) required for the hot cathode fluorescent lamp is also larger than that of the cold cathode fluorescent lamp. 15 Also, the backlight for liquid crystal displays should be about 5 times longer than the hot cathode fluorescent lamps used for general illumination. This is because the cold cathode fluorescent lamp used as the backlight source has a life of 60,000 hours. To ensure the same life, the hot cathode fluorescent lamp needs to have a life of five times that of a general lighting user. Therefore, in order to mount more emitters and increase the filament coil 20, the preheating power is also increased and the heat generation of the hot cathode fluorescent lamp for general illumination is significantly improved. As a result, it has been found that the above-mentioned large amount of heat generation causes deterioration of the optical member of the liquid crystal display portion which is not resistant to high temperature, and causes a problem of adversely affecting the enamel. With the trend of thinning the liquid crystal display in recent years, the volume in the backlight unit is reduced, and the distance between the backlight and the optical member is also reduced by 200903104, and it is foreseen that the problem will be more prominent. In the actual backlight unit, in order to cope with the heat generation problem of the hot cathode fluorescent lamp, a heat radiating member such as a fan is required, but the cost is increased. Even so, once the power supply is reduced to the extent that the heat generated by the hot cathode fluorescent lamp does not affect the optical components, the niche of the hot cathode fluorescent lamp itself will be lost. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its main object is to provide a structure which can solve the problem of heat generation in a simple configuration in a backlight having a hot cathode fluorescent lamp. 10 means for solving the problem The backlight of the present invention comprises: a hot cathode fluorescent lamp; and a lamp holder for holding the hot cathode fluorescent lamp; the hot cathode fluorescent lamp comprises: a lamp tube; a phosphor is formed on the inner surface; and a filament is disposed in the lamp tube to emit hot electrons; the lamp holder is disposed outside the lamp tube in the field of 15 filaments existing in the filament, and the lamp is The seat is made of metal material. The field in which the filament is present is preferably in the range of 10 mm from the center of the filament. Another backlight of the present invention comprises: a hot cathode fluorescent lamp; and a lamp 20 seat for holding the hot cathode fluorescent lamp; the hot cathode fluorescent lamp comprises: a lamp tube, and a fluorescent lamp is formed on the inner surface a light body; and a filament disposed in the lamp tube to emit hot electrons; the lamp holder can maintain the outer surface of the lamp tube from a position where the filament exists to an end side of the lamp tube, and The aforementioned lamp holder is composed of a metal material. 7 200903104 In a preferred embodiment, the aforementioned socket is entirely constructed of a metallic material. In a preferred embodiment, a resin material containing a filler is formed in the gap between the lamp holder and the lamp tube. In a preferred embodiment, the backlight is used in a direct type image display device. In a preferred embodiment, the backlight is used for a light source of a liquid crystal display having a face size of 32 吋 to 46 。, and the backlight is provided with 4 to 6 of the above-described hot cathode fluorescent lamps. In an embodiment, the backlight is composed of four layers of coils. In the embodiment, the hot cathode fluorescent lamp has a rated life of 20,000 hours or more. In an embodiment, the filament of one of the pair of electrodes of the hot cathode fluorescent lamp is coated with an emitter of 5.0 mg or more. In the embodiment, the gas pressure in the bulb of the hot cathode fluorescent lamp is 15 500 Pa or more. In an embodiment, the cross section of the tube of the hot cathode fluorescent lamp is circular. In the embodiment, the cross section of the lamp of the hot cathode fluorescent lamp is slightly elliptical. Advantageous Effects of Invention According to the backlight of the present invention, the lamp holder can hold the outer surface of the lamp tube in the field where the filament exists in the filament, and the lamp holder is made of a metal material, so that even if a heat dissipating member such as a fan is not used, Compared with the resin base, it can also achieve a significant cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS 200903104 FIG. 1 is an exploded perspective view showing the configuration of an image display device 1000 including a backlight 1 ο 0 of an embodiment of the present invention. Fig. 2 is a cross-sectional view schematically showing a hot cathode fluorescent lamp 10 of an embodiment of the present invention. 5 Fig. 3 is a cross-sectional view showing the configuration of a backlight 100 of an embodiment of the present invention. Fig. 4 is a plan view showing the configuration of a backlight 100 of an embodiment of the present invention. Fig. 5 is a perspective view showing the configuration of the socket 7 5 of the embodiment of the present invention. 6(a) and 6(b) are plan views showing the configuration of a backlight of an embodiment of the present invention. Fig. 7 is a perspective view showing the configuration of a socket 75 of an embodiment of the present invention. 15 Fig. 8 shows a graph showing the effect of temperature reduction based on the temperature [°C] of the reflector. Figures 9(a) and 9(b) show the relationship between the position of the tube axis direction and the tube surface temperature. Figures 10(a) and 10(b) are graphs showing the relationship between the position in the tube axis direction and the tube surface temperature. Figures 11(a) and 11(b) show graphs showing the relationship between the position in the tube axis direction and the tube surface temperature. Figures 12(a) and 12(b) show graphs showing the relationship between the position in the tube axis direction and the temperature inside the lamp. 9 200903104 [Embodiment 3] The best mode for implementing the invention The inventor of the present invention did not use the current mainstream cold cathode neon lamp as the backlight for the liquid crystal display that is accelerated by the development of the large surface, and the consideration is changed to 5 Compared with cold cathode fluorescent lamps, each of the hot cathode fluorescent lamps (HCFLs) that require a large amount of power is researched and developed. The reason for the above change is to enhance the contrast of the LCD TV by utilizing the "larger output" of the hot cathode fluorescent lamp, and also to make the animation high-quality, and as a backlight compared with the cold cathode glory lamp. The number of fluorescent lamps used by the source can be greatly reduced, while the cost is reduced by one. However, the backlight using a hot cathode fluorescent lamp has an inherent problem of easily forming a high temperature as compared with a backlight using a cold cathode fluorescent lamp. When the backlight is formed at a high temperature, the optical member (such as an optical film or a reflecting plate) used in the backlight is not resistant to high temperatures, and the deterioration thereof may cause optical characteristics and image characteristics of the image display device 15 (liquid crystal display device). Deterioration. From the above, the inventor of the present invention accidentally discovered that in order to alleviate the high temperature influence from the hot cathode fluorescent lamp, once the lamp holder disposed normally away from the filament of the hot cathode fluorescent lamp is barely moved, the lamp holder is made of metal. According to this configuration, the backlight can be cooled without using a heat dissipating member, and the present invention has been completed. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, for the sake of simplification of description, the same reference numerals are used to represent components that substantially have the same function. Further, the present invention is not limited to the following embodiments. Hereinafter, a backlight 100 according to an embodiment of the present invention will be described with reference to Figs. 1 to 4 . 200903104 Fig. 1 is an exploded perspective view showing the structure of an image display device (liquid crystal display device) 1000 including the backlight 100 of the present embodiment, and Fig. 2 is a view schematically showing a hot cathode constituting the backlight 100 of the present embodiment. The cross-section structure of the worklight 10. The third and fourth drawings show a cross-sectional view and a top view of the structure of the back light source 100 and the image display device 1000 of the present embodiment, respectively. The backlight 1 of the present embodiment, as shown in Fig. 1, includes a hot cathode fluorescent lamp 10, and a socket 75 for holding the hot cathode fluorescent lamp 10. As shown in Fig. 2, the hot cathode fluorescent lamp 10 is composed of a bulb 12 having a phosphor (not shown) formed on the inner surface 12a, and a filament 10 14 for discharging hot electrons is provided in the bulb 12. . The socket 75 holds the filament 12 in the field 5 5 (not shown) outside the surface 12b of the tube 12, and the socket 75 is made of a metal material. The filament presence field 55 is preferably in the range of ± l 〇 mm in the range of, for example, the filament center position i4cs ± 3 〇 mm. 15 The lamp holder 7 5 in the example shown in Fig. 1 is entirely composed of a metal material such as aluminum, brass, stainless steel, iron (or electroplated iron), and the like. In the present embodiment, although the lamp holder 75 made of aluminum is used, even if the socket 75 is not made entirely of metal, it is possible to selectively form the filament in the field of the field 55. Further, the thickness of the socket 75 is not particularly limited and may be, for example, 2 inches or more. In one example of the present embodiment, a socket 75 having a thickness of 1 to 10 mm is used. In addition, the effect of the socket 75 and the like are left to be described later. The end of the hot cathode fluorescent lamp 10 of the present embodiment is provided with a cap 5〇. The cap 5 is made of, for example, a resin material (PET (polyethylene terephthalate), ρΒτ (polybutylene terephthalate (6), etc.) or a metal material (10). In the structure of the embodiment of the present invention, a pipe socket (not shown) is disposed around the cap 50 to be connected to an external terminal of the cap 50 (such as a pin-shaped terminal). The external terminals then extend toward a direction that is slightly perpendicular to the length 92 of the tube 12, such as the opposite direction of the screen direction 90. Alternatively, the outer terminal of the cap 5 can be formed extending from the longitudinal direction 92 of the bulb 5 12 from the end face of the cap 50. Hereinafter, the hot cathode fluorescent lamp 10 used in the backlight 1 of the present embodiment will be described. The hot cathode fluorescent lamp of the present embodiment is used as a backlight source, so that the service life is longer. The hot cathode fluorescent lamp 1 is preferably a rated life of 12,000 hours or more, and further preferably has a rated life of 20,000 hours or 30,000 hours. In addition, the life of a CRT (cathode ray tube) which has been widely used as a display for a long time is about 20,000 hours, so it is preferable to use a life with a longer life. The illustrated hot cathode fluorescent lamp 10 is composed of a straight tubular glass bulb 12 and a counter electrode 11 disposed at one end of the glass bulb 12. The glass tube 12 is made of sodium or glass or a slick (softening glass of softening point 675). The size of the glass bulb 12 is exemplified, and it is used for 32 pairs of lamps 12 having an outer diameter of 12 mm, a thickness of 0.8 mm, and a length of 730 mm. The bulb 12 has an outer diameter of 12 mm, a thickness of 0.8 mm, and a length of 1010 mm. For 65 忖 tube 12 outer diameter 25.5mm, thickness 0.8mm, length 1499mm. In addition, it is used for 1〇5 pairs of lamps 12 having an outer diameter of 38 mm, a thickness of 0.9 mm, and a length of 2367 mm. In addition, the thickness of the light camp can also be 1.0mm. A phosphor (not shown) is coated on the inner surface of the glass bulb 12. More specifically, a protective film made of alumina is formed on the inner surface 12a of the glass bulb 12, and a phosphor layer is laminated on the protective film. The luminescent body constituting the phosphor layer may be a rare earth phosphor that emits light of various colors such as red (Y2〇3: Eu), green (LaP〇4: Ce, Tb3), and 12 200903104 blue (BaMg2Al16027: Eu, Mn). Mixed by. In addition, other rare earth phosphors can also be used for the phosphor. For example, red can use (Y, La) 2〇3: Eu, 3.5MgO. 0.5MgF2. Ge〇2: Μη, green can use CeMgAlnOw: Tb, GdMgB2O10: Ce, Tb, blue 5 can be used (Sr , Ca) 10(PO4)6Ci2 : Eu. Mercury and an inert gas are enclosed in the bulb 12. In the present embodiment, about 5 mg of mercury (not shown) is contained in the bulb lamp 12, and argon (Ar) having a pressure of 500 Pa at a normal temperature as a buffer inert gas is enclosed. Further, the mercury enclosed in the bulb 12 may be sealed in the form of a mercury alloy such as zinc mercury, tin water, silver, antimony or indium, in addition to the mercury monomer. Further, in addition to the mixing ratio of the inert gas to argon (Ar) of 100%, a mixture of argon (Ar) and krypton (Kr) may be used. The mixing ratio (partial pressure ratio) of krypton (Kr) is, for example, 20% to 60%, for example, it may be argon: 氪 = 50%: 50% of a mixed gas (air pressure: 6 〇〇 Pa) 〇 15 electrode 11 of this embodiment It consists of a filament 14, a pair of wires 13 for holding the filament 14, and a glass bead 15 for holding the pair of wires 13. Broken King is also known as the Pearl. The electrode π shown in the figure is a so-called glass beading method. The filament 14 is made of tungsten. In the example of the structure of the present embodiment, in order to extend the life of the _ and increase the amount of the coating of the emitter, a complicated coil shape is formed, that is, the town is loosely entangled in the thicker crane line. A linear structure is formed in a line, and the structure is wound into a spiral shape, which is called a two-layer coil filament 14. The three-layer coil is re-wound into a spiral shape to form a three-quot;~~' coil. 'Or the above three layers of coils are further wound into a spiral shape to form a four-figure & When the filament 14 is a three-layer coil, the coil of the third layer is an electrode line of 5 to 7 turns 13 200903104. Further, when the filament 14 is a four-layer coil, it is an electrode coil of 2 to 4 turns. The emissive system applied to the filament 14 is an oxide such as barium or calcium. In the present embodiment, 'in order to extend the life of the lamp, the amount of the emitter applied to the filament 14 is increased'. In the present embodiment, the filament enthalpy of one of the pair of electric 5 poles has been used for each of the hot cathode fluorescent lamps. The emitter is coated with 5.0 mg or more. Further, the composition of the inert gas is not the use of 100% argon, and the atomic amount is larger than the argon of argon at a predetermined mixing ratio to make it difficult for the emitter to scatter from the filament 14, which is technically prolonged. The illustrated electrode 11 is sealed to the sealing portion 16 of the glass bulb 12. Further, at least one end of the glass bulb 12 is sealed with an exhaust pipe 17. When the exhaust pipe 17 is used for exhausting or enclosing an inert gas from the bulb 12, it is sealed after the exhaust gas is sealed and sealed. Further, if the exhaust pipe 17 is provided at both ends of the lamp tube 12, the exhaust gas and the gas can be effectively enclosed. Moreover, by this, the proportion of impurities inside the bulb 12 can also be lowered. 15 The end of the glass tube 12 is provided with a cap 50 to cover the sealing portion 16 and the exhaust pipe. Further, the method of connecting the extension portion 18 of the lead wire 13 extending outward from the sealing portion 16 to the cap 50 can be appropriately determined in accordance with the specifications of the fluorescent lamp. Specifically, an external terminal (such as a pin) formed on the cap 50 can be electrically connected to the extension 18 of the wire 13. The external terminal (not shown) 20 of the cap 5 is connected to a stem (not shown). As shown in the first, third, and fourth figures, the backlight 100 including the hot cathode fluorescent lamp is mounted in the image display device 1 , and the backlight of the embodiment is used for the direct type. The backlight of the image display device. Further, the backlight 100 can be used as a planar light source for a liquid crystal display such as 26 Å or more (preferably 32 Å or more, such as 32 吋, 40 14 200903104 吋, 42 吋, 46 吋, 65 吋, etc.). Further, in Fig. 1, although the liquid crystal panel 6A is not shown, a liquid crystal panel is shown in Fig. 3. In the illustrated example, six hot cathode fluorescent lamps 1 配置 are exemplified. However, the number of the 5 hot cathode fluorescent lamps is not limited to this number. Further, in a preferred embodiment of the present embodiment, four to six hot cathode fluorescent lamps are arranged for the panel of the liquid crystal display having a screen size of 32 吋 to 46 。, and the lighting and the operation can be performed. Further, the socket 75 may be a structure for holding all of the fluorescent lamps 1 (6 in this example), or a structure for holding each of the fluorescent lamps, or 10 each holding a plurality of A constructor of a branch (such as 2 or 3). The reflecting plate 21 for accommodating a portion of the casing of the backlight 1 of the present embodiment is made of a metal plate such as an electroplated iron or aluminum article and has a thickness of l_5 mm. In the illustrated example, one of the reflecting plates 2 is bent in a convex shape (triangular shape) to constitute the auxiliary reflecting plate 22. A reflection sheet 23 is formed on the upper surface of the reflection plate 21 including the auxiliary reflection plate 22 15 (the main surface 20b of the case). The reflection sheet 23 is composed of a resin layer of polyethylene terephthalate (PET) dispersed by white titanium oxide (or calcium carbonate), and has a thickness of 2. mm. A portion of the apex (or ridgeline) of the auxiliary reflector 22 forms a post 24 that is used to support the underside of the optical film 30. The pillar 24 is made of a white resin. Further, the height Η of the backlight shown in Fig. 3 (the height from the upper surface of the reflecting plate 21 to the surface on which the optical film 3 is located) is, for example, 27 mm. Further, as shown in Fig. 3, a lighting circuit (ballast circuit or ballast) 70 may be disposed under the reflector 21 of the backlight unit 1 . In this example, the respective lighting lamps 10 are provided with a lighting circuit 70. Therefore, six lighting lamps 10 are used for the six fluorescent lamps 10 200903104. However, the number of lighting circuits 7G and Μ(4) may also differ. The lighting circuit 70 is electrically connected to the fluorescent lamp 1 via the cap 50, and also has a dimming function. Below the reflector 21, a lower cover 72 is provided, and a circuit 7 is provided. The lower cover 72 is thick! ·The metal plate of the 5th position. ^ Cover: 5 such as wiring is disposed in the space between the reflecting plates 21. In addition, the backlight may or may not be provided with the lower cover 72. In this case, the lighting circuit 7 may be first disposed in a casing of a liquid crystal display such as a liquid crystal television. Further, as shown in Fig. 4, the above-mentioned lamp holder is provided at the end of the reflecting plate 21. In this example, the optical film 3〇 includes the deflecting sheet 31 in order from the top (Dual Brightness, Sumitomo 3μ 10) Enhancement Fiim), thickness 440 mm), lens sheet 32 (thickness G155 mm), diffusion sheet 33 (thickness G n3 mm), diffusion plate 34 (thickness 2. Gmm). A lens sheet may be further disposed under the diffusion plate 34. Further, on the optical (4) 3G, a liquid crystal Φ plate (such as a thickness of about 15 2) 6G ′ is provided, and a liquid crystal panel (9) and an optical cymbal 30 are also provided. The upper cover 62 is composed of a metal plate such as a thick 15 face. In addition, the image display area 65 (refer to Fig. 4) of the example is 1〇18_573匪, but it is not limited to the size of the sea, and may be other sizes. Further, the periphery of the illuminating lamp is covered as a frame area so as to shield the non-point-storing portion of the fluorescent lamp 10, and the non-lighting portion is not externally displayed. Also observed by the backlight plus X, the liquid crystal panel 60 is located in the direction of the screen, that is, 9 屏幕. Next, a fifth embodiment of the hot cathode fluorescent lamp and the lamp holder 7S of the present embodiment will be described with reference to Fig. 5, and Fig. 5 is a perspective view showing a hot cathode glory lamp 1 and a lamp holder %. 16 200903104 As described above, the lamp holder 75 of the present embodiment can hold the fluorescent lamp 借 by keeping the filament existing in the filament 14 present outside the tube 12 of the field 55, and the lamp holder 75 is not made of an insulating material ( In particular, it is composed of a resin and is composed of a metal material. 10 15 20 Below, it is compared with the current mainstream cold cathode fluorescent lamp (CCFL). The voltage (drive voltage) required for driving a cold cathode fluorescent lamp is large, which is characterized by it. Therefore, the electro-recording resistance of the flash is large, and if there is metal, the electric/VIL leakage will occur. The occurrence of a far current leakage will result in uneven brightness in the shaft of the fluorescent lamp and a reduction in the problem of shouting. Therefore, even if a lamp ^ is used to hold the cold cathode glory lamp, only a resin (insulating material) article can be used. The reason why the lamp voltage of the cold cathode glory lamp is higher is as follows. The cold bulb is placed on the (four) of the glass tube (4), and the shape is the inert gas (Ne or Ar) of the buffer hole body and the appropriate amount of mercury. The electrode is formed by recording the metal into a cylindrical shape. Discharge occurs when a high voltage is applied between the electrodes. The cold cathode fluorescent is different from the mystery (four), the county emits electrons from the pole, and the electrode supplies electrons, so it requires a very high cathode effect voltage (100 to 200V). The cathode fluorescent lamp is about 1 〇v.) Further, when the cold cathode illuminating lamp is thin, and the t (four) drum is used, the high phase voltage of the falling voltage is changed to form a high tube voltage (lamp voltage). Therefore, it is extremely difficult to use a conductive material (metal material) for a lamp holder of the above-mentioned higher voltage lamp. In addition, the hot cathode glory lamp has a characteristic of a large amount of calving compared with a cold cathode glory lamp. _The hot cathode fluorescent lamp is different from the cold cathode fluorescent lamp in that it uses a lamp electrode that can be placed on a tweezers, and the electric power (power) required for the hot cathode fluorescent lamp is compared with the cold cathode Luguang 17 200903104 lamp. Larger. Use the above hot cathode fluorescent lamp In order to avoid the influence of heat, the lamp holder should be disposed away from the filament of the hot cathode fluorescent lamp. If the lamp holder is arranged in the high temperature region near the filament, the lamp holder may be easily deformed into a 5-shape. Replacing a typical resin product with a metal product to form a lamp holder, and arranging it in the vicinity of a filament that is usually not disposed. In the experiment, the cooling effect of the backlight is accidentally found. The cooling temperature can reach a remarkable effect equivalent to a cooling method such as a fan. 10 The cooling effect is described with reference to Figures 6 to 8. The inventors of the present invention prepared a set of a metal lamp holder 75 and a hot cathode fluorescent lamp, and conducted an experimental measurement of the temperature. The hot cathode fluorescent lamp was used. The lamp tube 12 of the 10 is slightly elliptical in shape, and the filament 14 is observed in the longitudinal direction and the transverse direction. The 6th (a) is a hot cathode fluorescent lamp in which the filament 14 is vertically disposed. The figure 15 is shown in Fig. 6(b) as a hot cathode fluorescent lamp in which the filament 14 is placed. In addition, the cap 50 in Fig. 6(a) is marked perpendicular to the longitudinal direction of the tube 12. Extended pin (external terminal) 51. If the pin 51 faces the side of the cap 5 If the direction is extended, the design of the narrow bezel (ie, the edge outside the screen display area) can be made easier. 20 The structure of the hot cathode fluorescent lamp 10 shown in Fig. 6(a) is a perspective view of Fig. 5. To be shown, it will be as shown in Fig. 7. However, the structures shown in Fig. 6(a) and Fig. 6(b) are such that the lamp holder 75 is offset from the filament center position i4c by a distance L2 (8 mm), and the lamp holder 75 Use a lamp holder with a thinner thickness (in this case, imm). In addition, the outer edge of the lamp holder 75 (reference line) to the outer length L1 (long frame length, 18 200903104, non-display surface) is 3〇 Further, in the same configuration as in the sixth drawing (Fig. 6), the lamp holder was prepared, and the lamp holder was prepared as a comparative example (reference standard). The results are shown in Figure 8. Fig. 8 is a graph showing the results of the measurement of the glory of the lamp 12, which is the structure shown in Fig. 5 and Fig. 6(b). In addition, the vertical axis in Fig. 8 represents the temperature rc] of the reflecting plate, and the horizontal axis represents the input power between the systems after dimming. When the input power [W] is about 130W, it represents the backlight used by the experiment. The Duty ratio is roughly dimmed, and the left and right represent the dimming state of _ ratio of 10 40% or less. In addition, the control of the dimming is performed by changing the power by the p-double control. As shown in Fig. 8, in the range where the duty ratio is 4% or more, the wire (C) of the comparative example (resin base) and the wire (A) and (B) of the metal base are compared. It can be found that the cooling effect of about 20 C, in the range of Duty less than 4% of the range of 15% 'also found that about 25 ~ catching cooling effect. In addition, the line (8) [and 10] of the 8th towel corresponds to the form of Figures 6(a) and 6(b), respectively. The results of lines (A) and (B) corresponding to Figures 6(a) and 6(b) are roughly the same, so it is inferred that even with the hot cathode fluorescent lamp 10 of the circular tube 12, the result will be The same. The above-mentioned cooling effect can be achieved without using a member such as a cooling fan, which is generally unimaginable. That is, in general, in order to achieve a certain degree of cooling (such as ίοc or greater cooling), it is necessary to use a dedicated member such as a cooling fan or to discard the use of a large lamp power. That is, the heat resistance of the reflecting plate 21 and the optical film 30 cannot be avoided, and even if the brightness of the lamp is to be increased, assuming that the temperature rise of 1 〇C is a limit (that is, a design constraint), only the additional cold 19 200903104 is required. Parts (such as cooling fans), drastically change the thermal design of the backlight, or discard the increase in lamp output (brightness). However, according to the configuration of the present embodiment, the lamp holder 75 is made of a metal product, and the peripheral temperature of the lamp (especially, the temperature of the reflecting plate 21 and the optical film 30) is remarkably lowered. Therefore, no new parts cost and thermal design development cost can be achieved, and the cooling effect can be achieved, which will provide a great technical contribution. Moreover, with the structure of the present embodiment, even if a cooling and heat dissipating mechanism is added, the cooling effect of the embodiment can be utilized, so that it can be added simply and inexpensively, or the possibility of a slight change can be changed even if the thermal design is changed. improve. 10 Therefore, this point is also of great technical value. In addition to the assembly stability with the lamp holder 75, in order to improve the heat dissipation of the fluorescent lamp 10, a resin material 77 containing a filler is preferably provided in the gap between the lamp tube 12 and the lamp holder 75 (refer to Fig. 7). . The resin material 77 may be composed of a polyfluorene oxide sheet containing a filler, and the heat conductivity of the resin material 77 15 may be increased by the type of the filler to improve heat dissipation. For example, when AGO3, BN, AIN, and Si〇2 are added as an inorganic filler to the resin (or an elastomer composed of a resin) 77, the thermal conductivity can be improved. Also, the thermal expansion coefficient can be adjusted by selecting an appropriate inorganic filler. The reason why the lamp holder 75 can be cooled by using a metal product is as follows. It can be inferred that the thermal conductivity is different due to the resin lamp holder and the metal lamp holder. That is, it can be inferred that compared with the resin, the thermal conductivity of the metal is as high as 1000 times or more, so the heat of the hot cathode fluorescent lamp, especially the filament, exists in the field 55, and can be transmitted to the backlight via the metal lamp holder 75. In the case of the source and the air, the result is a significant increase in heat dissipation efficiency. 20 200903104 In the embodiment of Fig. 8, it has been confirmed that although the thickness of the metal lamp holder 75 is only one, the presence of such a small member can achieve a cooling effect equivalent to that of the Han cooling 4 . /
員著之降溫效果出現於本案發明人檢討使用财熱性 5权η㈣作為保持與冷陰極螢光燈相較之下產熱量極大 ^熱陰㈣光燈之燈座之材質之過程中。㈤熱性較高之材 料可為金屬、陶兗等，但本案發明人亦考量加工性及材料 成本 t作了金屬製之燈座。而，本案發明人將通常避 開间皿之燈絲存在領域而遠離燈絲而配設之燈座，偶然配 10設於燈絲存在領域時，偶然發現顯著之降溫效果’而達到 該顯著之降溫效果。另，前述降溫效果幾乎未對最冷點溫 度所影響之燈效率造成影響，則加以說明如下。 第12圖係45对用之背光源（長ιοί〇mm)中，以橫軸代表 以單側之燈絲線圈之中心位置F為原點之管轴方向之距 15離，再將燈内之溫度分布作圖而成者。第12(a)圖係就未設 有管帽之螢光燈，第12(b)圖係就設有管帽之螢光燈，分別 以140mA、400mA、540mA之燈電流加以點亮之圖表。 由第12(a)及12(b)圖可知’燈内之溫度之最低點（最冷點) 位於螢光燈之管軸方向中央附近P，距離兩端之金屬製燈座 2〇最遠’故直接之影響車父小。因此，本發明之金屬製燈座可 解決液晶顯示部之光學構件之熱問題，而幾乎不會影響前 述燈效率。 另，由第12(a)及12(b)圖可知’燈絲領域d因受燈絲之 影響而溫度高於其它領域。因此，即便金屬製燈座之冷卻 21 200903104 放果亦無法使燈絲存在領域D之溫度低於螢光燈之管軸方 向中央附近P之溫度q卩，藉金屬製燈座而冷卻之部分將不 形成最冷點。 其次，參照第9〜第11圖，就燈絲14周邊(燈絲存在領域） 5之恤度为布加以說明。各圖之(a)部分係顯示管面溫度[。(：] 與管軸方向位置[mm]之關係者，⑻部分則係顯示管軸方向 位置所對應之螢光燈之載面圖。 第9(a)圖中之線(A)及(B)分別代表橫向配置橢圓燈之 長徑時之上面及側面之測定結果。第1〇(幻圖中之線(A)及(B) 亦與第9圖之關係相同。另，第9圖係反相器（點亮電路)輸入 40W，燈輸入3〇w時之結果，而，第1〇圖係反相器（點亮電 路)輸入26W，燈輸入9W時之結果。 進而，第11(a)圖中之線(A)及(B)分別為燈輸入為9”及 30W，且橫向配置橢圓燈之長徑時之側面之測定結果。如 15第U(b)圖所示，第U(a)圖之測定係就未於燈管12設有管帽 5〇者實施者。 由第9〜第11圖之結果可知，在距燈絲14之中心位置 14c30mm以内之範圍内存在高溫之領域。換言之，燈絲14 之中心位置14c起±3〇mm之範圍内，以位於該範圍外之基線 2〇為基準，存在可知如山一般之高溫領域。第9(a)圖及第i0(a) 圖所示之圖表中，因管帽50之影響而出現燈端面侧之線自 對稱形狀偏移者，但觀察未設管帽5〇之第11圖，則可知對 稱之線上出現了山形。其次，在自燈絲14之中心位置l4c起 ±l〇mm之範圍内，由山形較高之領域（即更高溫之領域）所 22 200903104 占，故該位置上配置金屬製之燈座75,可獲得更大之效果。 另，上述之30mm或10mm之領域之關係基本上，在任 何熱陰極螢光燈10皆相同，故利用本實施例之技術，即可 達成金屬製之燈座75之顯著之降溫效果。即便熱陰極登光 5燈10之形態改變，燈絲存在領域55在自燈絲中心位置14c起 30mm或l〇mm之範圍内，均可適用，其理由如下。 首先，因為熱陰極螢光燈之長度（即燈管12之長度）即使 改變，熱陰極螢光燈10之電極構造11，特別是燈絲14周邊 之基本構造亦未改變。即，熱陰極螢光燈1〇中，使用預定 10之燈絲14，其則藉預定之構造（導線13等）而固定，該基本構 造即使為諸如32吋用螢光燈，或65吋用螢光燈，亦無改變。 且，封入於燈管12之氣體種類、氣壓亦在熱陰極螢光燈1〇 之良好動作條件下無甚改變，且燈絲14周邊之溫度亦不致 大幅變化。 15 此外，即便燈管12之玻璃直徑改變，燈管長向（管軸方 向）之位置上，高溫領域（燈絲存在領域55)之範圍亦無變 化。亦即，因為若燈管12之玻璃直徑改變，則燈絲14與燈 管12之管壁之距離將改變而因此影響溫度，但就燈管長向 (管軸方向）之位置而言，將維持相同之傾向。此在第9及第 20 10圖中，可由即便測定截面成橢圓形之燈管12之不同點（(A) 及(B))之溫度’即測定燈絲14與燈管12之管壁之距離不同之 處，若沿燈管長向（管軸方向）之位置觀察，燈絲14之周邊之 向溫領域(燈絲存在領域55)亦無改變之情形，即可理解。 進而’自燈絲中心位置14c起至燈端部側之領域，與可 23 200903104 規定為燈絲存在領域55而自燈絲中心位置14c起±30mm之 範圍重疊，故亦可將金屬製之燈座75配置於燈絲中心位置 14c至燈端部側，以達到顯著之降溫效果。 以上，已依較佳實施例說明本發明，但上述記載並非 5 限定事項，而當然可進行各種變更。 舉例言之，熱陰極螢光燈10之燈管12之截面不限於圓 形（或略圓形），一如上述，亦可使用略橢圓形（橢圓形、長 圓、其它扁平形狀）者。熱陰極螢光燈10之燈絲（線圈）14之 構造及配置亦可採用適當之設計。另，管帽50之外部端子 10 雖例示為針銷形狀者，但不限於此，亦可使用其它形狀者 (諸如矩形者）。 又，本發明之實施例之背光源一如上述，適用於諸如 32吋以上之大晝面液晶電視，但不限於此，亦可適用於中 型（諸如26吋〜14吋)之液晶電視。此外，不限於液晶電視， 15 亦可使用作為其它影像顯示裝置（特別是大畫面者）之背光 源，或使用作為廣告看板之背光源。 產業上之利用可能性 依據本發明，即可於具有熱陰極螢光燈之背光源内以 簡易之構造解決產熱問題。 20 【圖式簡單說明】 第1圖係說明包含本發明之實施例之背光源10 0之影像 顯示裝置1000之構造之分解立體圖。 第2圖係模式地顯示本發明之實施例之熱陰極螢光燈 10之截面圖。 24 200903104 第3圖係顯示本發明之實施例之背光源100之構造之截 面圖。 第4圖係顯示本發明之實施例之背光源100之構造之平 面圖。 5 第5圖係說明本發明之實施例之燈座75之構造之立體 圖。 第6(a)、6(b)圖係顯示本發明之實施例之背光源之構造 之平面圖。 第7圖係說明本發明之實施例之燈座7 5之構造之立體 10 圖。 第8圖係顯示以反射板之溫度[°C]為依據之溫度降低效 果之圖表。 第9(a)、9(b)圖係顯示管軸方向之位置與管面溫度之關 係之圖表。 15 第10(a)、10(b)圖係顯示管轴方向之位置與管面溫度之 關係之圖表。 第11(a)、11(b)圖係顯示管軸方向之位置與管面溫度之 關係之圖表。 第12(a)、12(b)圖係顯示管轴方向之位置與燈内溫度之 20 關係之圖表。 【主要元件符號說明】 10…熱陰極螢光燈 12a…内面 11…電極 12b…外面 12…玻璃燈管 13…導線 25 200903104 14···燈絲 34…擴散板 14c…燈絲中心位置 50…管帽 15…玻璃珠 55…燈絲存在領域 16…密封部 60· ··液晶面板 Π…排氣管 62…上罩 18…延長部 65···影像顯示領域 20b· · ·主面 70···點亮電路 21…反射板 72…下罩 22···輔助反射板 75…燈座 23…反射片 77…樹脂材料 24…支柱 90…屏幕方向 30…光學膜片 92…燈管長向 3l···偏向片 100…背光源 32·"透鏡片 1000…影像顯示裝置(液晶顯示 33…擴散片 裝置） 26The cooling effect of the member appeared in the case of the inventor of the present invention reviewing the use of the financial property 5 η (4) as a material for maintaining the heat of the lamp holder of the heat (four) light lamp compared with the cold cathode fluorescent lamp. (5) The materials with higher heat can be metal, ceramics, etc., but the inventors of this case also consider the processability and material cost. However, the inventor of the present invention would normally avoid the presence of the filament of the dish and away from the filament, and occasionally match the presence of the filament in the field of the filament, and occasionally find a significant cooling effect, and achieve this significant cooling effect. Further, the aforementioned cooling effect hardly affects the lamp efficiency affected by the coldest spot temperature, and will be described below. Figure 12 is a pair of backlights used in 45 pairs (length ιοί〇mm), with the horizontal axis representing the distance from the center of the filament coil of the one-sided coil to the origin of the tube axis, and then the temperature inside the lamp. Distribution drawing. Figure 12(a) shows a fluorescent lamp without a cap, and Figure 12(b) shows a fluorescent lamp with a cap, which is illuminated by a lamp current of 140 mA, 400 mA, and 540 mA, respectively. . It can be seen from the figures 12(a) and 12(b) that the lowest point (the coldest point) of the temperature inside the lamp is located near the center of the tube axis direction of the fluorescent lamp, and is farthest from the metal lamp holder 2〇 at both ends. 'So the direct influence of the car father is small. Therefore, the metal base of the present invention can solve the thermal problem of the optical member of the liquid crystal display portion without affecting the above lamp efficiency. Further, as can be seen from the figures 12(a) and 12(b), the filament field d is higher in temperature than other fields due to the influence of the filament. Therefore, even if the cooling of the metal lamp holder 21 200903104 fails, the temperature of the filament D in the field D is lower than the temperature q of the vicinity of the center of the tube axis of the fluorescent lamp, and the portion cooled by the metal lamp holder will not Form the coldest point. Next, referring to the ninth to eleventh drawings, the cloth around the filament 14 (the field in which the filament is present) 5 will be described as a cloth. Part (a) of each figure shows the tube surface temperature [. (:) is related to the tube axis direction position [mm], and the (8) part is a map showing the position of the fluorescent lamp corresponding to the position in the tube axis direction. Lines (A) and (B) in Fig. 9(a) ) The results of the measurement of the upper side and the side of the long diameter of the elliptical lamp are respectively arranged. The first line (the lines (A) and (B) in the magic picture are also the same as the relationship of Fig. 9. In addition, the figure 9 is The inverter (lighting circuit) inputs 40W, the result of the lamp input 3〇w, and the first picture is the inverter (lighting circuit) input 26W, and the lamp input is 9W. Further, the 11th ( a) The lines (A) and (B) in the figure are the measurement results of the sides when the lamp input is 9" and 30W, and the long diameter of the elliptical lamp is arranged laterally. As shown in Figure 15, U(b), The measurement of the U(a) diagram is not carried out by the lamp cap 12. The results of the ninth to eleventh figures show that there is a high temperature within a range of 14 cm within 30 mm from the center position of the filament 14. In other words, the center position 14c of the filament 14 is within ±3〇mm, and the high-temperature field is known as a mountain, based on the baseline 2〇 outside the range. Fig. 9(a) and i0(a) ) as shown In the graph, the line on the side of the lamp end face is offset from the symmetrical shape due to the influence of the cap 50, but observing the 11th figure in which the cap 5 is not provided, it can be seen that a mountain shape appears on the line of symmetry. Secondly, in the self-filament The center position of 14 is within the range of ±1〇mm from the range of ±1〇mm, which is occupied by the high-density field (ie, the field of higher temperature) 22 200903104. Therefore, the metal lamp holder 75 is arranged at this position, which can achieve greater effect. In addition, the relationship between the above-mentioned fields of 30 mm or 10 mm is basically the same in any of the hot cathode fluorescent lamps 10, so that the significant cooling effect of the metal lamp holder 75 can be achieved by the technique of the embodiment. The shape of the hot cathode light 5 lamp 10 is changed, and the filament presence field 55 is applicable within a range of 30 mm or 10 mm from the filament center position 14c for the following reasons. First, because of the length of the hot cathode fluorescent lamp ( That is, even if the length of the lamp tube 12 is changed, the electrode structure 11 of the hot cathode fluorescent lamp 10, particularly the basic structure of the periphery of the filament 14, is not changed. That is, in the hot cathode fluorescent lamp, a predetermined filament 10 is used. , which borrows the predetermined structure ( The line 13 is fixed, and the basic structure is unchanged even if it is a fluorescent lamp such as 32 , or a fluorescent lamp of 65 。. Moreover, the gas type and air pressure enclosed in the bulb 12 are also in the hot cathode fluorescent light. There is no change under the good operating conditions of the lamp, and the temperature around the filament 14 does not change greatly. 15 In addition, even if the glass diameter of the lamp tube 12 changes, the position of the tube in the longitudinal direction (tube axis direction), the high temperature field There is no change in the range of the filament presence area 55. That is, if the glass diameter of the bulb 12 is changed, the distance between the filament 14 and the tube wall of the bulb 12 will change, thereby affecting the temperature, but the length of the tube The position of the (tube axis direction) will maintain the same tendency. In Figs. 9 and 20, the distance between the filament 14 and the tube wall of the tube 12 can be determined by measuring the temperature ('A) and (B)) of the tube 12 having an elliptical cross section. The difference is that if the position along the longitudinal direction of the tube (the direction of the tube axis) is observed, the direction of the temperature in the vicinity of the filament 14 (the field of filament presence 55) is not changed. Furthermore, the field from the filament center position 14c to the lamp end side overlaps with the filament presence area 55 and the range of ±30 mm from the filament center position 14c, so that the metal base 75 can be arranged. At the filament center position 14c to the lamp end side, a significant cooling effect is achieved. The present invention has been described above based on the preferred embodiments, but the above description is not a limitation of the invention, and various modifications can of course be made. For example, the cross section of the bulb 12 of the hot cathode fluorescent lamp 10 is not limited to a circular shape (or a slightly circular shape), and as described above, a slightly elliptical shape (oval shape, long circle, or other flat shape) may be used. The construction and arrangement of the filament (coil) 14 of the hot cathode fluorescent lamp 10 can also be suitably designed. Further, although the external terminal 10 of the cap 50 is illustrated as a pin shape, it is not limited thereto, and other shapes (such as a rectangular shape) may be used. Further, the backlight of the embodiment of the present invention is suitable for a large-panel liquid crystal television such as 32 吋 or more as described above, but is not limited thereto, and is also applicable to a medium-sized (such as 26 吋 to 14 吋) liquid crystal television. Further, it is not limited to a liquid crystal television, and 15 can also be used as a backlight for other image display devices (especially for large screens) or as a backlight for an advertising billboard. Industrial Applicability According to the present invention, the heat generation problem can be solved with a simple structure in a backlight having a hot cathode fluorescent lamp. [Brief Description of the Drawings] Fig. 1 is an exploded perspective view showing the configuration of an image display device 1000 including a backlight 100 of an embodiment of the present invention. Fig. 2 is a cross-sectional view schematically showing a hot cathode fluorescent lamp 10 of an embodiment of the present invention. 24 200903104 Fig. 3 is a cross-sectional view showing the configuration of a backlight 100 of an embodiment of the present invention. Fig. 4 is a plan view showing the configuration of a backlight 100 of an embodiment of the present invention. 5 Fig. 5 is a perspective view showing the configuration of a socket 75 of an embodiment of the present invention. 6(a) and 6(b) are plan views showing the configuration of a backlight of an embodiment of the present invention. Fig. 7 is a perspective view showing the configuration of the socket 7 5 of the embodiment of the present invention. Fig. 8 is a graph showing the effect of temperature reduction based on the temperature [°C] of the reflecting plate. Figures 9(a) and 9(b) show the relationship between the position of the tube axis direction and the tube surface temperature. 15 Figures 10(a) and 10(b) show the relationship between the position of the tube axis direction and the tube surface temperature. Figures 11(a) and 11(b) show graphs showing the relationship between the position in the tube axis direction and the tube surface temperature. Figures 12(a) and 12(b) are graphs showing the relationship between the position in the tube axis direction and the temperature in the lamp. [Description of main component symbols] 10...hot cathode fluorescent lamp 12a...inner surface 11...electrode 12b...outer surface 12...glass tube 13...wire 25 200903104 14···filament 34...diffuser 14c...filament center position 50...cap 15...glass bead 55...filament existence area 16...sealing portion 60···liquid crystal panelΠ...exhaust pipe 62...upper cover 18...extension portion 65···image display area 20b···main surface 70··· Bright circuit 21...reflector 72...lower cover 22···auxiliary reflector 75...lamp holder 23...reflector 77...resin material 24...strut 90...screen direction 30...optical diaphragm 92...light tube length 3l·· · deflecting sheet 100...backlight 32·"lens sheet 1000...image display device (liquid crystal display 33...diffuser device) 26