200823565 九、發明說明： 【發明所屬之技術々貝域】 發明領域 本發明係有關於使用為液晶顯示器等顯示裝置之背光 5 之照明裝置及具有該照明裝置作為光源之顯示裝置。 I：先前技術3 發明背景 .近年來’液晶電視、液晶螢幕等液晶顯示裝置的書面 尺寸漸趨大型化。比起過去，為求薄型化，主要採用玻璃 10 燈泡為較細直徑之冷陰極型放電燈作為液晶顯示裝置之背 光單元之光源。 冷陰極型放電燈適用於裝置之薄型化，但燈效率不太 高，故，隨著液晶顯示裝置之晝面尺寸的大型化，耗電量 也會變大，因此，從省能源的觀點來看，有盡量不要採用 15作為大型液晶顯示裝置之背光單元之光源的傾向。 > 又，若晝面尺寸大型化，則冷陰極型放電燈之玻璃燈 泡的長度會變長，且電極間距離會變大，因此，在點燈時， 必須進-步施加高電壓。因此，若採用冷陰極型放電燈作 為大型液晶顯示裝置之背光單元的光源，則也有來自升壓 s 20 t路之漏電流所造成之電力損失變大之缺點。 ^ 因此，這幾年來，開始採用較冷陰極型放電燈高效率 ’、、' a "^放电燈作為大型液晶顯示裝置之背光單元的光 源0 又為控制製品成本，關於減少背光單元之光源之熱 200823565 陰極型放電燈的數量之研究開發漸趨活络。 但:一旦作為光源之熱陰極型放電燈的數量較少，則 在背光早70所射出之射出光會產生亮度不均。，在背光 單元之光射出面中’從熱陰極型放電燈之配設位置附近領 域會射出^度的光，但從遠離熱陰極型放電燈之配設位 置附近領域則只會射出低亮度的光，BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination device using a backlight 5 as a display device such as a liquid crystal display, and a display device having the illumination device as a light source. I: Prior Art 3 Background of the Invention In recent years, the written sizes of liquid crystal display devices such as liquid crystal televisions and liquid crystal screens have become larger. In comparison with the past, in order to reduce the thickness, a glass 10 bulb is mainly used as a light source of a backlight unit of a liquid crystal display device. The cold cathode type discharge lamp is suitable for the thinning of the device, but the lamp efficiency is not so high. Therefore, as the size of the face of the liquid crystal display device is increased, the power consumption is also increased, and therefore, from the viewpoint of energy saving. See, there is a tendency to try not to use 15 as a light source for a backlight unit of a large liquid crystal display device. > Further, when the size of the kneading surface is increased, the length of the glass bulb of the cold cathode type discharge lamp becomes long, and the distance between the electrodes becomes large. Therefore, when lighting, a high voltage must be applied in advance. Therefore, if a cold cathode type discharge lamp is used as the light source of the backlight unit of the large liquid crystal display device, there is a disadvantage that the power loss due to the leakage current from the step s 20 t is increased. ^ Therefore, in the past few years, the use of cold cathode discharge lamps with high efficiency ', ' a " discharge lamps as the backlight unit of large liquid crystal display devices 0 is also the cost of control products, on reducing the backlight unit light source The heat of 200823565 The research and development of the number of cathode discharge lamps is becoming more and more active. However, once the number of the hot cathode type discharge lamps as the light source is small, unevenness in brightness is generated in the light emitted from the backlight 70. In the light exit surface of the backlight unit, 'the light from the vicinity of the arrangement position of the hot cathode type discharge lamp is emitted, but only in the vicinity of the arrangement position away from the hot cathode type discharge lamp, only low brightness is emitted. Light,
10 :此，在專散獻十録_财㈣=^之 間的空間配設有對應於各熱陰極型放電燈之大小的擴散 片。在專利文獻丨中，藉由配設該擴散片，可抑制亮度不均 的產生。 【專利文獻1】特開平6-130384號 【發明内容】 發明概要 然而，在專利文獻1之構造中，必須在熱陰極型放電燈 15與擴散板之間另外配設用以保持各擴散片之構件，且製造 # 步驟變得複雜，同時，有成本變高之虞。 更重要的是，在專利文獻1之構造中，從熱陰極型放電 燈射出的光並不會全部通過該擴散片，因此，產生亮度不 均的問題依然無法獲得解決。 ^ 20 本發明有鑑於上述問題點，以提供即使光源的燈數較 v 少’亦可抑制亮度不均之照明裝置及顯示裝置為目的。 解決問題之手段 本發明之照明裝置包含具有開口部之框體、配設於該 框體内之放電燈及用以覆蓋前述框體之開口部之前面面 6 200823565 板’且當將前述放電燈之管軸設為χ軸，將與該x軸垂直且 與前述前面面板平行之軸設為Y軸，將與X軸及Y軸垂直之 ^ 軸設為Z軸時，前述前面面板具有：光折射構件，係使從前 述放電燈放射的光折射後射出者；及擴散、集光構件，係 5使從珂述光折射構件射出的光擴散及集光者，又，前述光 折身ί構件在將Y〜2平面（與前述前面面板之主面平行的面） 之光的入射角設為(9 i，射出角設為，且0 1>〇時，滿 • 足002之關係下，使入射光折射後射出。 發明之效果 1〇 藉由本發明人等之努力研究關於擴散、集光構件之光 擴散功能得到以下的見解。 過去射入前述擴散、集光構件的光的入射角有很多 種。在遠離光源之放電燈之領域中，從放電燈放射的光會 以大入射角射入擴散、集光構件。擴散、集光構件具有光 15擴散功能，但所射出之光的強度對光之入射角的依存度仍 # 高。即，以大入射角射入擴散、集光構件的光即使藉由該 光擴散功能擴散，所射出的光仍會依存於入射角，射出角 大的光會射出較多。射出角大的光即使藉由前述擴散、集 光構件之集光功能亦不易集光，因此對照明裝置之亮度難 ^ 2〇 有助益。 • 本發明中，藉由前述擴散、集光構件，特別是在遠離 放電燈之領域，可縮小射入前述擴散、集光構件的光的入 射角。藉此，藉由前述擴散、集光構件之擴散功能擴散而 射出的光的射出角會變小。因此，該射出光藉由前述擴散、 7 200823565 集光構件之集光功能容易集光，因此，有助於提高遠離玫 電燈之領域的亮度。 如此-來，根據本發明，特別是在遠離放電燈之領域 中，會射出較過去更強的光，因此，可改善過去所產生之 5照明裝置之射出光之亮度不均。 於此月’』述光折射構件會抑制前述放電燈射出的光之 中相對於零件表面之入射角小的光之透過率，同時隨著入 射角變大，使光的透過率逐漸増加，以調整從前述放電燈 放射之光的透過。 ίο #由上述構造，從前述放電燈放射的光之中，對前述 光折射構件之入射角愈小的光，則愈可藉由光折射構件抑 制透過率，而入射角愈大的光，透過光折射構件的光會愈 多。藉此，即使光源之燈數較少，針對從照明裝置之光射 出面射出的光亦可改善亮度不均。 15 又，在上述中，前述光折射構件具有稜鏡列，前述稜 鏡列宜與前述放電燈之管軸平行並列地配設。 藉此，以簡單的構造可抑制放射至放電燈之附近領域 的光的透過性’同時可提高遠離前述放電燈之領域的光的 透過性。 20 於此，在上述中，前述稜鏡列在前述光折射構件中， 宜形成於與前述擴散、集光構件相向之部份的全部。 藉此，均勻的光會射入擴散、集光構件，故可減少照 明裝置之亮度不均。 於此，在上述中，前述稜鏡列之各稜鏡呈與前述放電 200823565 燈之官軸垂直之截面形狀為大略三角形之形狀，且各棱鏡 之頂角之角度在80。以上120。以下，且前述各稜鏡之頂角部 ^ 份宜與前述擴散、集光構件相向。 • 胃各彳《鏡之頂肖不到8G。，則從構造力學上的觀點來 5看，會不易保持其形狀，而若超過12〇。，則集光特性會過 度下降。 又，上述中，前述各稜鏡之頂角之角度宜為90。。 • 纟各棱鏡之頂角為90。時，最可提高前述光折射構件之 集光特性。 10 ⑨此’在上述中’在前述放電燈與前述光折射構件之 間宜配設有用以使前述放電燈所放射的光擴散之輔助擴散 構件。 精由配設該輔助擴散構件，可抑制亮度不均，同時可 減小前述框體的厚度。 15 又，在上述中，於前述框體内並列地配設有多數前述 _ 放電燈’ #將前述放電燈之配設_設為P[mm]，且將前述 放電燈之管軸與前述前面面板之距離設為d[mm]，並將前述 放電燈之管軸與前述框體之底面之距離設為且將前 述放電燈之框體之厚度方向之發光徑設為rl[mm_，宜滿 、2〇 足〇.1〇印+〇/1><0·40，且 1.7<(d+f)/rl<4之關係。 ， 滿足上述條件，藉由在前述框體内配設放電燈，可抑 制壳度不均，且減少放電燈之所需數量。 於此’在上述中’放電燈具有與管軸垂直之截面呈扁 平形狀之玻璃燈泡，且扁平形狀之長内徑宜配設成與前述 9 200823565 V 5 框體之底面平行。 在上述構造中，由於玻璃燈泡呈扁平形狀，故藉由朝 背光單元之厚度方向配設燈之玻璃燈泡之短内徑，可達成 背光單元之薄型化。另，本說明書中所謂「扁平形狀」為 在上下方向將截面圓形之玻璃管弄扁，且以上下方向之内 徑為短内徑，並以左右方向之内徑為長内徑，且除了包含 與輪廓相向之兩個平的部份及聯繫這兩個平的部份之曲線 部份的形狀以外，亦包含整個輪廓以曲線表示之橢圓形狀。 本發明之顯示裝置具有上述任一所記載之照明裝置作 10 為光源。 藉此，由於具有上述亮度不均少之照明裝置作為光 源，故可提供從顯示面射出之光的亮度分布均勻之顯示裝 置。 圖式簡單說明 15 第1圖係顯示本發明之液晶顯示裝置，為知道内部的樣 子，為缺少一部分的圖。 第2圖係顯示本實施形態之屏幕比例16 : 9之液晶顯示 器用背光單元5之構造之概略透視圖。 第3圖係第2圖之A—A向剖面圖。 20 第4圖係為說明光折射片13之背光單元之截面圖。 曹 第5圖係為說明光折射片13的功能之背光單元的截面 圖。 第6圖係顯示背光單元之亮度分布特性之圖表。 第7圖係顯示本實施形態之熱陰極型放電燈20之構 10 200823565 造，第7(a)圖係平面截面圖，第7(b)圖係在第7(a)圖中以B —B截面切斷時之橫截面圖。 第8圖係顯示變形例之背光單元之構造之截面圖。 第9(a)圖、第9(b)圖係變形例之熱陰極型放電燈之橫截 5 面圖。 I：實施方式】 較佳實施例之詳細說明 以下，針對本發明實施形態之背光單元及液晶顯示裝 置一面參照圖式一面說明。 10 <液晶顯示裝置之構造> 首先，參照第1圖針對本實施形態之液晶顯示裝置之構 造作說明。第1圖係顯示本發明之液晶顯示裝置，為知道内 部的樣子，為缺少一部分的圖。 液晶顯示裝置1例如為彩色液晶電視，液晶晝面單元3 15 與背光單元5組入本體4。液晶晝面單元3例如具有彩色濾光 片基板、液晶、TFT基板、驅動模組等（未圖示），且根據來 自液晶畫面單元3外部之影像訊號將彩色影像顯示於液晶 畫面單元3之晝面6。 <背光單元之構造> 20 參照第1圖針對本實施形態之液晶顯示裝置之構造作 說明。第2圖係顯示本實施形態之屏幕比例16 : 9之液晶顯 示器用背光單元5之構造之概略透視圖。該圖中為顯示内部 構造，欠缺前面面板18的一部分來顯示。 如第2圖所示，背光單元5具有多數熱陰極型放電燈（以 11 200823565 下表記為「燈」）20、具有開口部用以收納該等燈之框體 10、用以覆蓋該框體10之開口部之前面面板18。 框體10例如用鋁製之板金形成具有開口之箱體，且在 其内面11貼上具白色擴散反射特性之聚酯板（本實施例 ^ 5 中，使用東立製E60L)。 燈20呈直管狀，本實施形態中，4根燈20以正下方之方 式配設於框體10内，且並列地電連接。燈20藉由未圖示之 ^ 亮燈電路作定電流控制。另，關於燈20之構造則在後述。 在各燈20之間之框體10内配設有呈三角柱狀之輔助反 10 射板12。輔助反射板12可有效地使從燈20射出之直接光或 從燈20射出且由前面面板18反射之間接光反射至前面面板 18 〇 框體10之開口部由光折射片13、擴散板14、擴散片15、 透鏡片16及偏光片17所積層而成之透光性之前面面板18覆 15 蓋，且密閉成灰塵或塵埃等異物不會跑入内部。 關於前面面板18中之光折射片13的功能在後面詳細說 明。擴散板14及擴散片15用以使透過光折射片13的光擴散 者。透鏡片16用以使透過擴散板14及擴散片15的光集光且 朝該透鏡片16之法線方向偏向者，藉由上述，從燈20發出 20 的光會擴及前面面板18之表面（發光面）整體均勻地照射前 方。 接著，參照第3圖，針對燈20在框體1〇内之配設位置作 說明。第3圖係第2圖之A —A向剖面圖。另’光折射片13具 有三角形之稜鏡列T，該稜鏡列之三角形頂點配設成與擴散 12 200823565 板14抵接，在光折射片13與擴散板14之間隙形成空氣層 19。又’在第3圖中，將燈2〇之管軸方向設為X軸，且將與 該X軸垂直且與前面面板18平行之軸設為γ軸，並將與χ軸 及Υ軸垂直之軸設為Ζ軸。 5 如第3圖所示，燈20隔著距離P[mm]之間隔等間隔地並 列配設。另，各燈20由固定於框體1〇底面且與亮燈電路電 連接之導電性保持構件(省略圖式)保持。 又’燈20配設成電極線圈31之線圈軸與框體1〇之底面 平行’且配置於與前面面板18之距離為d[mm]之位置。此 10時’電極線圈31之線圈軸與框體10之底面之距離為f[mm]。 在如此配置之燈20中，前述框體1〇之厚度方向之發光徑 rl[mm]為短内徑，而與底面平行之方向之發光徑r2[mm^ 長内徑。 於此，距離P、d、f宜滿足下列式子1之關係。 15 0.01 ^(d+f)/P< 0.40 (式子 1) 若（d+f)/P小於〇·1，則即使如本實施形態配設光折射片 13 ’亦無法解決亮度不均，若(d+f)/P大於0.4，則無法產生 減少燈20的數量之效果。 再者，若考量燈的數量及照明裝置的厚度，則距離P、 ° d、f宜滿足下列式子2之關係。 0.30^ (d+f)/P< 0.35 (式子2) 再者，使用發光徑rl為14mm的燈，且為實際上試作及 汗估厚度d+f在20〜60mm之間之背光單元的結果所得之經 驗式。相對於具有不同之rl之值的燈，宜滿足下列式子3之 13 200823565 1*7<(d+f)/ri<4 (式子 3) 右（d+f)/rl小於17，則燈發光面與光折射片i3會過度 接近而無法充分發輝光折射片B的功能。又，若(d+〇斤1 5大於4，則不一定要配置光折射片13也可得到高均一度。 接著，參照第4圖，說明光折射片13。第4圖係為說明 光折射片13之背光單元5之放大截 面圖。另，第4圖中，前 述前面面板18中僅顯示光折射片13，並省略其他擴散板 M、透鏡片16等之圖式。 1〇 光折射片13在聚酯系樹脂之平板層13a具有接合多個 丙烯系樹脂之三角形稜鏡13b之構造之三角稜鏡列τ。光折 射片13配設成三角稜鏡列Τ之長向與燈20之管軸方向大致 平行。 以入射角01射入光折射片丨3的光經過聚酯系樹脂層 15 13a丙烯系樹脂層Ub之折射，以射出角朝擴散板14射 出。該射出光以入射角射入擴散板14。 根據本發明人等之努力研究，關於擴散板14之光擴散 功能得到以下的見解。 過去射入擴散板14的光的入射角有很多種。在遠離光 20源之燈20的領域中，從燈2〇放射的光會以大入射角射入擴 散板14。擴散板14具有光擴散功能，但所射出之光的強度 對光之入射角的依存度仍高。即，以大入射角射入擴散板 14的光即使藉由該光擴散功能擴散，從擴散板14射出的光 仍會依存於入射角，射出角大的光會射出較多。射出角大 14 200823565 的光即使藉由透鏡片16之集光功能亦不易集光，因此對背 光單元5之亮度難有助益。 本實施形態中，藉由光折射片13，特別是在遠離燈2〇 之領域，可縮小射入擴散板14的光的入射角02。藉此，藉 由擴散板14之擴散功能擴散而射出的光的射出角會變小。 因此，該射出光藉由透鏡片16之集光功能容易集光，因此， 有助於提高遠離燈20之領域的亮度。 10 15 20 如此一來，根據本實施形態之構造，特別是在遠離燈 20之領域中，會射出較過去更強的光，因此，可改善過去 所產生之背光單元5之射出光之亮度不均。 接著，參照第5圖說明光折射片13。第5圖係為說明光 折射片13的功能之背光單元的截面圖。另，第5圖中，前述 前面面板18中僅顯示光折射片13，並省略其他擴散板14、 透鏡片16等之圖式。 射出至燈20之附近領域且以小入射角射入光折射 片13的光L1會以折射角叩!通過三角稜鏡列τ之頂角，且從 三角稜鏡列之頂點垂直地射出至光折射片13之主面。另， 若將空氣之折射率設為⑽，且將光折射#13之㈣旨系樹脂 層13a之折射率設為•則人射_丨與折射脚丨會滿足史 奈爾法則。人射角㈣、折射角_、折射率脱、折射率^ 會滿足下列式子3之關係。 ηα · sin(0al) =n/j · sin(叩i) (式子3) 另一方面，射出至燈2〇之附近領域以入射角⑽射入 先折射片13輸2在聚料、樹脂層13如折射角辑射 15 200823565 後，由於構成稜鏡之丙烯系樹脂層13b為三角形，故會在丙 烯系樹脂層13b與空氣層19之間全反射。在三角稜鏡之斜面 反射的光會朝框體1〇之底面方向射出。該反射光藉由框體 10之内面11或辅助反射板丨2、燈20之玻璃燈泡等反射，且 5再射入光折射片13，以有效地利用。 遠離燈20之配設位置之領域的光，即，以大入射角 、0α4射入光折射片的光會射入光折射片13且依據史奈 φ 爾法則折射，並通過三角稜鏡之頂角，且以大致垂直之平 行射出至擴散板14之主面。 10 即，藉由如上所述地配設光折射片13，具有與光剛好 從直射光不會強烈照射之領域放射出來的情況同樣的效 果。 即，藉由在燈20與擴散板14之間配設光折射片13，從 燈20射出的光可通過光折射片13，藉此在射入擴散板14之 15前面階段變得均勻，且之後透過擴散板14、透鏡片且從前 • 面面板18射出的光也會沒有局部性亮度高低而均勻。如此 一來，根據本實施形態，即使作為光源的燈2〇的數量較少， 亦可抑制直射光之透過，且該所減少的光的一部分會從過 去直射光不會射出之領域射出，因此，可改善背光單元之 20 免度不均等過去的問題。 <效果> 接著，參照第6圖，說明本實施形態之背光單元之效 果。第6圖係顯示背光單元之亮度分布特性之圖表。實線所 示之圖表為本實施形態之背光單元5(實施例）之資料，虛線 16 200823565 所示之圖表為習知例（比較例）之背光單元之資料。圖表之縱 軸為前面面板面亮度（相對值）[%]，橫軸為亮度測定位置 [mm]。另，橫軸0加叫之位置相當於前面面板18最下方之 位置，且400[mm]之位置相當於前面面板最上方之位置。 5 如第6圖所示，在比較例中，在遠離燈20之領域中，前 面面板面亮度在40%以下，且會產生亮度不均。相對於此， 在實施例中’即使是離燈20較遠的領域，亦可保持將近知 馨 ％之前面面板面亮度，且本實施例相較於比較例可大幅改 善亮度不均。 10 [燈20之構造] 接著，針對燈20之構造作說明。第7圖係顯示本實施形 態之熱陰極型放電燈（以下有時僅稱作「燈」。）2〇之構造， 第7(a)圖係平面截面圖，第7(b)圖係以B~B截面切斷時之橋 截面圖。 15 燈20具有直管狀玻璃燈泡22及配設於玻璃燈泡22内兩 φ 端之一對電極30a、30b。 玻璃燈泡2 2為鋇锶矽酸鹽玻璃（軟化點675 °C之軟質玻 璃）製。如第7(b)圖所示，玻璃燈泡22之與管軸垂直之截面 呈具有長内徑C1與短内徑C2之橢圓形。如此一來，由於玻 ， 20璃燈泡22呈橢圓形，故將燈20之玻璃燈泡22之短内徑配置 略 於背光單元5之厚度方向，即，藉由將玻璃燈泡22之短内徑 配置成與前面面板18垂直，可使背光單元5薄型化。 又，在玻璃燈泡22之其中一端（圖中左侧端部）密封有排 氣管2名。該排氣管28係使用在排出玻璃燈泡22内之氣體或 17 200823565 填封稀有氣體時，且在上述排氣及填封之後密封。藉由在 其中一端設置排氣管28而非在玻璃燈泡22之兩端，最冷點 控制可更為容易。即，此係由於若設於兩端則會不知最冷 點處在哪一邊之故。 5 電極30a、30b由三重繞且6.5轉之電極線圈31a、31b、 固持該等電極線圈3la、31b之一對導線32a、32b、33a、33b、 保持該等導線32a、32b、33a、33b之管狀玻璃34a、34b所 構成。電極線圈31a、31b為例如鶏製，且塗上錄、躬、鋇 之氧化物作為射極。 10 在玻璃燈泡22内面形成有鋁製保護膜24。在保護膜24 上積層有螢光體層26。螢光體層26中之螢光體係使用混合 了可發出紅（Y2〇3 : Eu)、綠（LaP04 : Ce，Tb3)及藍 (BaMgiAlaO27 : Eu、Μη)各色之稀土類螢光體的東西。 在玻璃燈泡22内填入約5mg的水銀21與作為緩衝用稀 15 有氣體常溫下之壓力為500Pa之氬(Ar)。 另’填入玻璃燈泡22内之水銀21除了水銀單體亦可以 例如鋅水銀、錫水銀、銦水銀等汞齊之形態填入。 於此，針對使用於45吋液晶顯示器用背光單元時之燈 20之各尺寸專的樣本敛述。 20 玻璃燈泡22之長内徑C1為17mm，短内徑c2為10mm， 全長L〇為1010mm，電極間距離Leg95〇nim，管壁電荷We 為0_05(W/cm2)。另，管壁負荷為玻璃燈泡22中相當於電極 間距離Le之部份的内表面積除以燈電力之值。 如上所述，由於玻璃燈泡呈扁平形狀，故藉由將熱陰 18 200823565 極型放電燈之玻璃燈炮之短内徑配置於背光單元5之厚度 方向，可達成背光單元5之薄型化。 再者’若使背光單元5之框體1〇内的燈2〇至液晶面板的 距離與配置於背光單元5之框體10内的各燈20之燈間距離 5相等，則可抑制液晶顯示器之亮度不均。在本實施形態中， 由於將玻璃燈泡22之形狀設為橢圓形，故相對於電極線圈 31a、31b之長度，可增加燈2〇至液晶面板（未圖示）之距離。 伴隨於此’即使使配置於背光單元5之框體1〇内的各燈2〇之 燈間距離大到與燈2〇至液晶面板的距離相等之大小，亦可 10抑制亮度不均’故可增加配置於框體10内之燈20之燈間距 離，並可減少作為光源所需之燈20的數量。藉此，可減少 背光單兀5中所需的零件數量，故對背光單元5之低成本化 有幫助。 另’第2圖中，針對配設4根燈2〇之構造作說明，但燈 15 20之配設於背光單元5之框體10内之燈20的數量亦可因應 液晶顯示裝置的畫面大小等適度變更。 <變形例> 以上，雖根據實施形態說明本發明，但本發明的内容 當然不限於上述實施形態所示之具體例，例如，亦可考量 20 以下之變形例。 (1)上述中，針對光折射片13具有三角稜鏡列T之構造 作說明，但並不限於此，稜鏡列之各稜鏡亦可呈台形、多 角形或半圓形。又，稜鏡列不必全部呈同一形狀，亦可例 如在熱陰極型放電燈之配設位置之附近領域中，各稜鏡呈 19 200823565 角形且在遠離熱陰極型放電燈之領域中，各棱鏡呈半 圓形。 ()在上述中，針對光折射片13具有稜鏡列之構造作說 明，但光折射構件並不一定要具有稜鏡列。例如，光折射 片亦可為具有相當於燈2〇之位置的折射率高且隨著從該 位置在您離放電燈之領域，折射率會逐漸降低之折射率分 布之構4。藉此，可抑制放射至燈2〇之附近領域之光的透 過性，同時可提高放射至遠離燈2〇之領域的光的透過性， 口此即使作為光源之燈2()的數量較少，亦可改善背光單 10 元5之亮度不均。 (3)上述中，針對光折射片13與擴散板14抵接之構造作 ”兒明，但並不限於此。光折射片13只要配設於燈與擴散 板14之間即可，即，光折射片13亦可為不與擴散板14面接 觸而遠離擴散板14之構造。但，為縮小第3圖所示之距離d， 且達成裝置之薄型化，光折射片13宜配設成棱鏡之頂點與 擴散板14抵接。 (句在上述中，針對擴散板14、擴散片15、透鏡片16為 刀別獨立而個別的東西之情況作說明，但例如取而代之亦 可使用具有在使射入的光擴散後集光之功能之一片擴散、 20集光片。 (5)為達成裝置之薄型化，在第3圖中，若縮小燈2〇與光 折射片13之距離d，則燈2〇之直射光所射出之領域會變窄， 藉此，會助長亮度不均。因此，藉由以下之變形例之構造， 即使使裝置更薄型，亦可抑制亮度不均的產生。 20 200823565 第8圖係顯示變形例之背光單元之構造之截面圖。如第 8圖所不，在燈20與前面面板18之間的空間亦可配設辅助擴 散片19。藉此，由於可減少燈2〇之直射光強度，故可縮小 距離d，並可謀求裝置之薄型化。 5 (6)在上述中，針對燈20之玻璃燈泡如第7(b)圖所示為 與管軸垂直之截面為橢圓形者作說明，但並不限於此，2 要是有長内徑與短内徑之形狀的東西，無論何種形狀皆 可。第9圖係變形例之熱陰極型放電燈之橫截面圖。例如， 如第9(a)圖所示，亦可呈扁平形狀，且如第9(的圖所示，亦 1〇可呈長方形。此等情形亦由於長内徑〇1較短内徑〇之大小 大，故可增加電極線圈之軸方向之長度。又，藉由將燈2〇 之玻璃燈泡配設成短内徑C2與液晶面板面垂直，可達成裝 置之薄型化。 ^ (7)在上述中，針對燈2〇之玻璃燈泡為外觀看呈直線狀 15來撓明，但並不限於此，例如，燈2〇之玻璃燈泡亦可呈外 觀看為u字形、3字形等其他形狀。 又，燈20之玻璃燈泡亦可呈環狀，此時光折射片^之 稜鏡列從平面看時必須與玻璃燈泡之軸平行且環狀地配 設。此時亦可降低背光單元之亮度不均。 0 ⑻在上財’針對填人氬、氪作為緩衝用稀有氣體來 說明，但除此以外亦可填入氖或氣。由於氣之原子量大， 故可抑制塗在電極線圈之射極飛散，因此藉由填入氣，可 進一步增加壽命。 ⑼在上述中’針對在玻璃燈泡22内面形成保護膜24來 21 200823565 說明，但亦可不形成保護膜24。 (10) 在上述中’針對採用熱陰極型放電燈作為背光單元 之光源來說明，但並不限於此，例如，亦可取代熱陰極型 放電燈’採用冷陰極型放電燈、外部電極型放電燈或其他 5放電燈作為背光單元之光源。又，亦可取代一般的放電燈， 而為線狀地配列LED或燈泡等之線狀光源。此時亦為根據 本發明與上述相同之裝置，即使是較少的燈數，亦可改善 亮度不均。 (11) 在上述中，舉背光單元為例作為照明裝置來說明， 10但並不限於此，例如亦可為具框體及配設於該框體内之本 實施形態之熱陰極型放電燈之一般照明單元。 (12) 在上述中，舉液晶顯示裝置為例作為顯示裝置來說 明，但並不限於此，亦可例如為具有框體及配設於該框體 内之本實施形態之熱陰極型放電燈之看板裝置作為顯示裝 15置。 【產業上之可利用性】 本發明可廣泛地適用於照明裝置及顯示裝置。又，本 Ιχ明可k供即使光源之燈數較少亦可抑制亮度不均之照明 裝置及顯示裝置，故其產業利用價值極高。 20 【圖式簡單說明】 第1圖係顯示本發明之液晶顯示裝置，為知道内部的樣 子，為缺少一部分的圖。 第2圖係顯示本實施形態之屏幕比例16 : 9之液晶顯示 器用背光單元5之構造之概略透視圖。 22 200823565 第3圖係第2圖之A-A向剖面圖。 第4圖係為說明光折射片13之背光單元之截面圖。 第5圖係為說明光折射片13的功能之背光單元的截面 圖。 5 第6圖係顯示背光單元之亮度分布特性之圖表。 第7圖係顯示本實施形態之熱陰極型放電燈20之構 造，第7(a)圖係平面截面圖，第7(b)圖係在第7(a)圖中以B —B截面切斷時之橫截面圖。 第8圖係顯示變形例之背光單元之構造之截面圖。 10 第9(a)圖、第9(b)圖係變形例之熱陰極型放電燈之橫截 面圖。 【主要元件符號說明】 1…液晶顯示裝置 13b···三角形稜鏡 3·.·液晶畫面單元 13b…丙稀系樹脂層 4…本體 14…擴散板 5…背光單元 15···擴散片 6...晝面 16".透鏡片 10...框體 17...偏光片 11…内面 18…前面面板 12…輔助反射板 19···空氣層 13…光折射片 19...輔助擴散片 13a.··平板層 20…燈 13a...聚S旨糸樹脂層 21…水銀 23 200823565 22...玻璃燈泡 34a、34b…管狀玻璃 24···保護膜 Cl...長内徑 26…螢光體層 C2…短内徑 28...排氣管 T".稜鏡列 30a、30b...電極 01...入射角 31、31a、31b··.電極線圈 02...射出角 32a、32b、33a、33b...導線 d···距離 2410: In this case, a diffusion sheet corresponding to the size of each of the hot cathode type discharge lamps is disposed in a space between the exclusive recordings of the tenth (four) = ^. In the patent document, by disposing the diffusion sheet, generation of luminance unevenness can be suppressed. [Patent Document 1] JP-A-6-130384 [ SUMMARY OF INVENTION] SUMMARY OF THE INVENTION However, in the structure of Patent Document 1, it is necessary to additionally provide a diffusion sheet between the hot cathode type discharge lamp 15 and the diffusion plate. The components, and the manufacturing # steps become complicated, and at the same time, there is a cost increase. More importantly, in the structure of Patent Document 1, the light emitted from the hot cathode type discharge lamp does not pass through the diffusion sheet, and therefore, the problem of uneven brightness is still not solved. In view of the above problems, the present invention has an object of providing an illumination device and a display device capable of suppressing uneven brightness even if the number of lamps of the light source is smaller than v. Means for Solving the Problem An illumination device according to the present invention includes a housing having an opening, a discharge lamp disposed in the housing, and a front surface of the opening portion for covering the frame 6 200823565, and when the discharge lamp is to be used The tube axis is a χ axis, and an axis perpendicular to the x axis and parallel to the front panel is set to the Y axis, and when the axis perpendicular to the X axis and the Y axis is the Z axis, the front panel has: light a refractive member that refracts light emitted from the discharge lamp and emits the light; and a diffusion and light collecting member that diffuses and collects light emitted from the light-refractive member, and the light-reducing member When the incident angle of the light of the Y to 2 plane (the surface parallel to the main surface of the front panel) is (9 i, the emission angle is set to 0 1 > ,, the relationship between the full and the foot 002 is made. The incident light is refracted and is emitted. The effect of the present invention is that the light diffusion function of the diffusion and light collecting members is studied by the inventors of the present invention. The following observations have been made on the light incident on the diffusion and light collecting members. Kind of discharge lamp away from the light source In the domain, the light emitted from the discharge lamp enters the diffusing and collecting member at a large incident angle. The diffusing and collecting member has the function of diffusing the light 15, but the dependence of the intensity of the emitted light on the incident angle of the light is still # That is, even if the light incident on the diffusing and collecting member at a large incident angle is diffused by the light diffusing function, the emitted light still depends on the incident angle, and the light having a large exit angle is emitted more. Even if the light is collected by the light collecting function of the diffusion and light collecting members, it is difficult to collect light. Therefore, in the present invention, the diffusion and light collecting members are particularly used. In the field of the discharge lamp, the incident angle of the light incident on the diffusion and light collecting member can be reduced. Thereby, the emission angle of the light emitted by the diffusion and the diffusion function of the light collecting member is reduced. The emitted light is easily collected by the diffusing function of the light diffusing member of the 200823565 light collecting member, thereby contributing to the improvement of the brightness away from the field of the rose lamp. Thus, according to the present invention, particularly away from the discharge lamp It In the field, light that is stronger than in the past is emitted, so that the brightness unevenness of the emitted light of the five illumination devices generated in the past can be improved. This month, the light-refractive member suppresses the light emitted from the discharge lamp. The transmittance of light having a small incident angle with respect to the surface of the part is increased as the incident angle increases, and the transmittance of light emitted from the discharge lamp is adjusted to adjust the transmission of light emitted from the discharge lamp. Among the light emitted by the discharge lamp, the light having a smaller incident angle with respect to the light-refracting member can suppress the transmittance by the light-refracting member, and the light having a larger incident angle has more light transmitted through the light-refracting member. Thereby, even if the number of lamps of the light source is small, unevenness in brightness can be improved with respect to light emitted from the light exit surface of the illumination device. Further, in the above, the light-refracting member has a matrix, and the array It is preferably arranged in parallel with the tube axis of the discharge lamp. Thereby, the transmittance of light emitted to the vicinity of the discharge lamp can be suppressed with a simple structure, and the light transmittance from the field of the discharge lamp can be improved. In the above, in the above-mentioned light-refracting member, it is preferable that the above-mentioned enthalpy is formed in all of the portions facing the diffusion and light-collecting members. Thereby, uniform light is incident on the diffusion and light collecting members, so that uneven brightness of the illumination device can be reduced. Here, in the above, each of the arrays of the arrays has a substantially triangular shape in cross section perpendicular to the official axis of the discharge 200823565, and the angle of the apex angle of each prism is 80. Above 120. Hereinafter, it is preferable that the apex portion of each of the above-mentioned ridges is opposed to the diffusion and light collecting members. • The stomach is less than 8G. From the point of view of structural mechanics, it will be difficult to maintain its shape, and if it exceeds 12 〇. , the collection characteristics will be excessively reduced. Further, in the above, the angle of the apex angle of each of the above turns is preferably 90. . • The apex angle of each prism is 90. At the time, the light collecting characteristics of the aforementioned light-refracting member can be improved most. In the above, the auxiliary diffusion member for diffusing the light emitted from the discharge lamp is preferably disposed between the discharge lamp and the light-refracting member. By providing the auxiliary diffusion member, unevenness in brightness can be suppressed, and the thickness of the frame can be reduced. Further, in the above, a plurality of the above-mentioned _discharge lamps are arranged in parallel in the casing. #The discharge lamp is disposed as P[mm], and the tube axis of the discharge lamp is connected to the front surface. The distance between the panel is set to d [mm], and the distance between the tube axis of the discharge lamp and the bottom surface of the frame is set to be rl [mm_, the full diameter of the frame of the discharge lamp. 2, 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 。 。 。 。 。 。 。 。 。 。 。 。. When the above conditions are satisfied, by disposing the discharge lamp in the frame, the degree of unevenness of the shell can be suppressed, and the required number of discharge lamps can be reduced. Here, the above-mentioned "discharge lamp" has a flat glass bulb having a flat cross section perpendicular to the tube axis, and the long inner diameter of the flat shape is preferably arranged in parallel with the bottom surface of the above-mentioned 9 200823565 V 5 frame. In the above configuration, since the glass bulb has a flat shape, the backlight unit can be made thinner by disposing the short inner diameter of the glass bulb of the lamp in the thickness direction of the backlight unit. In the present specification, the "flat shape" is a flattened glass tube having a circular cross section in the vertical direction, and the inner diameter in the upper and lower directions is a short inner diameter, and the inner diameter in the left and right direction is a long inner diameter, and In addition to the shape of the two flat portions facing the contour and the curved portion connecting the two flat portions, the elliptical shape in which the entire contour is represented by a curve is also included. The display device of the present invention has the illumination device described in any of the above as a light source. As a result, since the illumination device having the above-described uneven brightness is used as the light source, it is possible to provide a display device in which the luminance distribution of the light emitted from the display surface is uniform. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a liquid crystal display device of the present invention in which a part of the liquid crystal display device of the present invention is missing. Fig. 2 is a schematic perspective view showing the structure of the backlight unit 5 for a liquid crystal display of the screen ratio 16:9 of the present embodiment. Figure 3 is a cross-sectional view taken along line A-A of Figure 2. 20 Fig. 4 is a cross-sectional view showing the backlight unit of the light refraction sheet 13. Cao 5 is a cross-sectional view of a backlight unit illustrating the function of the light refraction sheet 13. Fig. 6 is a graph showing the luminance distribution characteristics of the backlight unit. Fig. 7 is a view showing the structure 10 of the hot cathode type discharge lamp 20 of the present embodiment, 200823565, Fig. 7(a) is a plan sectional view, and Fig. 7(b) is shown in Fig. 7(a) as B. A cross-sectional view of the B section when it is cut. Fig. 8 is a cross-sectional view showing the configuration of a backlight unit of a modification. Fig. 9(a) and Fig. 9(b) are cross-sectional views of a hot cathode type discharge lamp according to a modification. I. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a backlight unit and a liquid crystal display device according to an embodiment of the present invention will be described with reference to the drawings. 10 <Structure of Liquid Crystal Display Device> First, the configuration of the liquid crystal display device of the present embodiment will be described with reference to Fig. 1 . Fig. 1 is a view showing a liquid crystal display device of the present invention in which a part of the liquid crystal display device of the present invention is missing. The liquid crystal display device 1 is, for example, a color liquid crystal television, and the liquid crystal top surface unit 3 15 and the backlight unit 5 are incorporated in the main body 4. The liquid crystal top surface unit 3 has, for example, a color filter substrate, a liquid crystal, a TFT substrate, a driving module, and the like (not shown), and displays a color image after the liquid crystal screen unit 3 based on an image signal from the outside of the liquid crystal screen unit 3. Face 6. <Structure of Backlight Unit> 20 The structure of the liquid crystal display device of the present embodiment will be described with reference to Fig. 1 . Fig. 2 is a schematic perspective view showing the structure of the backlight unit 5 for a liquid crystal display of the screen ratio 16:9 of the present embodiment. In the figure, the internal structure is shown, and a part of the front panel 18 is missing for display. As shown in FIG. 2, the backlight unit 5 has a plurality of hot cathode discharge lamps (hereinafter referred to as "lights" in the following table in 200823565), and a frame 10 having an opening for accommodating the lamps to cover the frame. The front panel 18 of the opening portion of 10. The casing 10 is formed of, for example, a plate made of aluminum, and has a box having an opening, and a polyester plate having a white diffused reflection property is attached to the inner surface 11 (in the present embodiment, the E60L manufactured by Toray Industries, Inc.) is used. The lamp 20 has a straight tubular shape. In the present embodiment, the four lamps 20 are disposed in the casing 10 directly below, and are electrically connected in parallel. The lamp 20 is controlled by a lighting circuit (not shown). The structure of the lamp 20 will be described later. An auxiliary counter-reflecting plate 12 having a triangular column shape is disposed in the frame 10 between the lamps 20. The auxiliary reflecting plate 12 can effectively emit the direct light emitted from the lamp 20 or the light emitted from the lamp 20 and reflected by the front panel 18 to the front panel 18. The opening portion of the frame 10 is composed of the light refraction sheet 13 and the diffusing plate 14. The translucent front panel 18, which is formed by laminating the diffusion sheet 15, the lens sheet 16, and the polarizer 17, covers the lid 15 and is sealed so that foreign matter such as dust or dust does not enter the inside. The function of the light refraction sheet 13 in the front panel 18 will be described in detail later. The diffusion plate 14 and the diffusion sheet 15 are for diffusing light that has passed through the light refraction sheet 13. The lens sheet 16 is configured to collect the light transmitted through the diffusing plate 14 and the diffusing film 15 and deflect toward the normal direction of the lens sheet 16. By the above, the light 20 emitted from the lamp 20 spreads to the surface of the front panel 18. The (light-emitting surface) is uniformly irradiated to the front as a whole. Next, referring to Fig. 3, the arrangement position of the lamp 20 in the casing 1A will be described. Figure 3 is a cross-sectional view taken along line A-A of Figure 2. Further, the light refraction sheet 13 has a triangular array T, and the triangular apexes of the array are disposed to abut against the diffusion 12 200823565 plate 14, and an air layer 19 is formed in the gap between the light refraction sheet 13 and the diffusion plate 14. Further, in Fig. 3, the tube axis direction of the lamp 2 is set to the X axis, and the axis perpendicular to the X axis and parallel to the front panel 18 is set as the γ axis, and will be perpendicular to the χ axis and the Υ axis. The axis is set to the x-axis. 5 As shown in Fig. 3, the lamps 20 are arranged in parallel at equal intervals with a distance P [mm]. Further, each of the lamps 20 is held by a conductive holding member (omitted from the drawing) fixed to the bottom surface of the casing 1 and electrically connected to the lighting circuit. Further, the lamp 20 is disposed such that the coil axis of the electrode coil 31 is parallel to the bottom surface of the casing 1 and is disposed at a position d[mm] from the front panel 18. The distance between the coil axis of the electrode coil 31 and the bottom surface of the casing 10 is f [mm]. In the lamp 20 thus arranged, the light-emitting diameter rl [mm] in the thickness direction of the frame body 1 is a short inner diameter, and the light-emission diameter r2 [mm^ long inner diameter in a direction parallel to the bottom surface. Here, the distances P, d, and f should satisfy the relationship of the following formula 1. 15 0.01 ^(d+f)/P<0.40 (Expression 1) If (d+f)/P is smaller than 〇·1, even if the light refraction sheet 13' is disposed as in the present embodiment, unevenness in brightness cannot be solved. If (d+f)/P is larger than 0.4, the effect of reducing the number of lamps 20 cannot be produced. Furthermore, if the number of lamps and the thickness of the illumination device are considered, the distances P, ° d, and f should satisfy the relationship of the following formula 2. 0.30^(d+f)/P<0.35 (Formula 2) Further, a lamp having a light-emitting diameter rl of 14 mm is used, and a backlight unit having a thickness of d+f of 20 to 60 mm is actually tried and sweated. The empirical formula obtained as a result. Relative to the lamp having a different value of rl, it is preferable to satisfy the following formula 3: 200823565 1*7<(d+f)/ri<4 (Expression 3) Right (d+f)/rl is less than 17, The light-emitting surface of the lamp and the light-refracting sheet i3 are too close to each other to sufficiently function as the glow-refractive sheet B. Further, if (d + 1 1 5 is larger than 4, high uniformity is not necessarily obtained by arranging the light refraction sheet 13. Next, the photorefractive film 13 will be described with reference to Fig. 4. Fig. 4 is a view showing the photorefractive film An enlarged cross-sectional view of the backlight unit 5 of Fig. 13. In Fig. 4, only the light refraction sheet 13 is shown in the front panel 18, and other patterns of the diffusion plate M, the lens sheet 16, and the like are omitted. The flat layer 13a of the polyester resin has a triangular array τ in which a plurality of triangular ridges 13b of a propylene resin are joined. The light refraction sheet 13 is disposed in a tube of the longitudinal direction of the triangular array and the tube of the lamp 20. The axial direction is substantially parallel. The light incident on the light refraction sheet 3 at the incident angle 01 is refracted by the acryl resin layer Ub of the polyester resin layer 15 13a, and is emitted toward the diffusion plate 14 at an emission angle. The emitted light is incident at an incident angle. Into the diffuser plate 14. According to an effort by the inventors of the present invention, the light diffusing function of the diffusing plate 14 has the following findings. There have been many incident angles of light incident on the diffusing plate 14 in the past. In the field, the light emitted from the lamp 2〇 will be incident at a large angle of incidence. The diffusing plate 14 has a light diffusing function, but the dependence of the intensity of the emitted light on the incident angle of the light is still high. That is, the light incident on the diffusing plate 14 at a large incident angle is even by the light diffusing function. Diffusion, the light emitted from the diffusing plate 14 still depends on the incident angle, and the light having a large exit angle is emitted. The light having a large exit angle 14 200823565 is not easily collected by the light collecting function of the lens sheet 16, so In the present embodiment, the light refraction sheet 13 can reduce the incident angle 02 of the light incident on the diffusing plate 14 by the light refraction sheet 13, particularly in the field away from the lamp. The emission angle of the light emitted by the diffusion function of the diffusing plate 14 is reduced. Therefore, the emitted light is easily collected by the light collecting function of the lens sheet 16, and therefore contributes to the improvement of the brightness in the field away from the lamp 20. 10 15 20 As a result, according to the configuration of the present embodiment, particularly in the field away from the lamp 20, light stronger than in the past is emitted, and therefore, the brightness of the light emitted from the backlight unit 5 generated in the past can be improved. Uneven. Next, refer to the fifth The light refraction sheet 13 will be described. Fig. 5 is a cross-sectional view of the backlight unit for explaining the function of the photorefractive film 13. In Fig. 5, only the light refraction sheet 13 is shown in the front panel 18, and other diffusion plates 14 are omitted. The pattern of the lens sheet 16 and the like. The light L1 emitted to the vicinity of the lamp 20 and incident on the light refraction sheet 13 at a small incident angle will be at the apex angle of the triangular 稜鏡 τ, and from the triangular rib The apex of the mirror array is perpendicularly emitted to the main surface of the light refraction sheet 13. Further, if the refractive index of the air is set to (10) and the refractive index of the resin layer 13a of the (4) light refraction #13 is set to be _丨 and the refraction ankle will satisfy the Snell's law. The human angle (4), the refraction angle _, the refractive index off, and the refractive index ^ will satisfy the relationship of the following formula 3. Ηα · sin(0al) =n/j · sin(叩i) (Formula 3) On the other hand, the area near the lamp 2〇 is incident on the first refraction sheet 13 at the incident angle (10). When the layer 13 is refracted by the refraction angle 15 200823565, since the propylene-based resin layer 13b constituting the crucible has a triangular shape, it is totally reflected between the propylene-based resin layer 13b and the air layer 19. The light reflected on the slope of the triangular ridge is emitted toward the bottom surface of the frame 1〇. The reflected light is reflected by the inner surface 11 of the casing 10 or the auxiliary reflecting plate 2, the glass bulb of the lamp 20, and the like, and is incident on the light refraction sheet 13 for efficient use. The light in the field away from the position where the lamp 20 is disposed, that is, the light incident on the light refraction sheet at a large incident angle of 0α4, is incident on the light refraction sheet 13 and refracted according to the Schneider's law, and passes through the apex angle of the triangular ridge And exiting to the main surface of the diffuser plate 14 in a substantially vertical parallel direction. In other words, by disposing the light refraction sheet 13 as described above, it has the same effect as the case where the light is emitted from the field where the direct light is not strongly irradiated. That is, by arranging the light refraction sheet 13 between the lamp 20 and the diffusion plate 14, the light emitted from the lamp 20 can pass through the photorefractive film 13, thereby becoming uniform in the front stage of the injection of the diffusion plate 14, and Then, the light that has passed through the diffusing plate 14 and the lens sheet and is emitted from the front panel 18 is also uniform without local brightness. As described above, according to the present embodiment, even if the number of the lamps 2 as the light source is small, the transmission of the direct light can be suppressed, and a part of the reduced light is emitted from the field where the direct light is not emitted in the past. It can improve the past problems of the 20-degree non-uniformity of the backlight unit. <Effects> Next, the effect of the backlight unit of the present embodiment will be described with reference to Fig. 6 . Fig. 6 is a graph showing the luminance distribution characteristics of the backlight unit. The graph shown by the solid line is the data of the backlight unit 5 (Example) of the present embodiment, and the graph shown by the broken line 16 200823565 is the data of the backlight unit of the conventional example (Comparative Example). The vertical axis of the graph is the front panel surface brightness (relative value) [%], and the horizontal axis is the brightness measurement position [mm]. Further, the position of the horizontal axis 0 is equal to the position of the lowermost portion of the front panel 18, and the position of 400 [mm] corresponds to the position of the uppermost portion of the front panel. 5 As shown in Fig. 6, in the comparative example, in the field far from the lamp 20, the front panel surface brightness is 40% or less, and uneven brightness is generated. On the other hand, in the embodiment, even in the field far from the lamp 20, the brightness of the front panel surface can be kept close to that of the lamp, and the luminance unevenness can be greatly improved in the present embodiment as compared with the comparative example. 10 [Structure of Lamp 20] Next, the structure of the lamp 20 will be described. Fig. 7 is a view showing a structure of a hot cathode discharge lamp of the present embodiment (hereinafter sometimes referred to simply as "light"), a plan view of Fig. 7(a), and a view of Fig. 7(b). A cross-sectional view of the bridge when the B~B section is cut. The lamp 20 has a straight tubular glass bulb 22 and a pair of electrodes 30a, 30b disposed at two φ ends in the glass bulb 22. The glass bulb 2 2 is made of silicate glass (soft glass having a softening point of 675 ° C). As shown in Fig. 7(b), the cross section of the glass bulb 22 perpendicular to the tube axis has an elliptical shape having a long inner diameter C1 and a short inner diameter C2. In this way, since the glass bulb 20 is elliptical, the short inner diameter of the glass bulb 22 of the lamp 20 is disposed slightly in the thickness direction of the backlight unit 5, that is, by arranging the short inner diameter of the glass bulb 22 Vertical to the front panel 18, the backlight unit 5 can be made thinner. Further, at the one end (the left end portion in the drawing) of the glass bulb 22, the name of the exhaust pipe 2 is sealed. The exhaust pipe 28 is sealed with a gas that is discharged from the glass bulb 22 or 17 200823565 to seal the rare gas, and after the above-described exhaust and sealing. By providing the exhaust pipe 28 at one end instead of at both ends of the glass bulb 22, the coldest point control can be made easier. In other words, if it is provided at both ends, it is not known which side is the coldest point. 5 electrodes 30a, 30b are three-folded and 6.5-turn electrode coils 31a, 31b, one of the electrode coils 31a, 31b is held to the wires 32a, 32b, 33a, 33b, and the wires 32a, 32b, 33a, 33b are held. The tubular glass 34a, 34b is constructed. The electrode coils 31a and 31b are, for example, tantalum, and are coated with an oxide of a recording, a krypton or a crucible as an emitter. 10 An aluminum protective film 24 is formed on the inner surface of the glass bulb 22. A phosphor layer 26 is laminated on the protective film 24. In the phosphor system of the phosphor layer 26, a rare earth-based phosphor in which red (Y2〇3: Eu), green (LaP04: Ce, Tb3), and blue (BaMgiAlaO27: Eu, Μη) colors are mixed is used. The glass bulb 22 was filled with about 5 mg of mercury 21 and argon (Ar) having a pressure of 500 Pa at room temperature as a buffer. Further, the mercury 21 filled in the glass bulb 22 may be filled with a mercury amalgam such as zinc mercury, tin mercury or indium mercury in addition to the mercury monomer. Here, a sample specific for each size of the lamp 20 used in the 45-inch backlight unit for a liquid crystal display is described. 20 The glass bulb 22 has a long inner diameter C1 of 17 mm, a short inner diameter c2 of 10 mm, a full length L〇 of 1010 mm, a distance between electrodes of Leg95〇nim, and a wall wall We We of 0_05 (W/cm 2 ). Further, the wall load is the internal surface area of the portion of the glass bulb 22 corresponding to the distance Le between the electrodes divided by the value of the lamp power. As described above, since the glass bulb has a flat shape, the backlight unit 5 can be made thinner by arranging the short inner diameter of the glass bulb of the thermal cathode 18 200823565 pole type discharge lamp in the thickness direction of the backlight unit 5. Furthermore, if the distance between the lamp 2 in the casing 1 of the backlight unit 5 and the liquid crystal panel is equal to the distance 5 between the lamps 20 arranged in the casing 10 of the backlight unit 5, the liquid crystal display can be suppressed. The brightness is uneven. In the present embodiment, since the shape of the glass bulb 22 is elliptical, the distance from the lamp 2 to the liquid crystal panel (not shown) can be increased with respect to the length of the electrode coils 31a and 31b. With this, even if the distance between the lamps of each of the lamps 2 disposed in the casing 1 of the backlight unit 5 is made larger than the distance from the lamp 2 to the liquid crystal panel, the brightness unevenness can be suppressed 10 The distance between the lamps of the lamps 20 disposed in the frame 10 can be increased, and the number of lamps 20 required as a light source can be reduced. Thereby, the number of parts required in the backlight unit 5 can be reduced, which contributes to the cost reduction of the backlight unit 5. In the second drawing, the configuration of the four lamps 2 is described. However, the number of the lamps 20 disposed in the casing 10 of the backlight unit 5 can also correspond to the screen size of the liquid crystal display device. Moderate changes. <Modifications> The present invention has been described above based on the embodiments, but the present invention is of course not limited to the specific examples described in the above embodiments, and for example, modifications of 20 or less may be considered. (1) In the above description, the configuration in which the light-refractive sheet 13 has the triangular array T is described. However, the present invention is not limited thereto, and the respective turns of the array may be in a trapezoidal shape, a polygonal shape or a semicircular shape. Moreover, the columns do not have to all have the same shape, and may be, for example, in the vicinity of the arrangement position of the hot cathode type discharge lamp, each of which is in the shape of an angle of 19 200823565 and in the field away from the hot cathode type discharge lamp, each prism It is semi-circular. () In the above description, the configuration in which the light refraction sheet 13 has a matrix is described, but the photorefractive member does not necessarily have to have a matrix. For example, the light-refracting sheet may have a refractive index distribution having a refractive index which is higher than the position of the lamp 2〇 and which gradually decreases in refractive index from the position of the discharge lamp from the position. Thereby, it is possible to suppress the transmittance of light which is radiated to the vicinity of the lamp 2〇, and at the same time, it is possible to increase the transmittance of light radiated to the area far from the lamp 2, even if the number of the lamps 2 () as the light source is small. It can also improve the brightness unevenness of the backlight unit 10 yuan 5. (3) In the above, the structure in which the light-refractive sheet 13 and the diffusing plate 14 are in contact with each other is described as follows. However, the light-reducing sheet 13 may be disposed between the lamp and the diffusing plate 14, that is, The light refraction sheet 13 may have a structure that is not in contact with the diffusion plate 14 and is away from the diffusion plate 14. However, in order to reduce the distance d shown in Fig. 3 and to achieve a reduction in thickness of the device, the photorefractive film 13 should be disposed so as to be The apex of the prism abuts against the diffuser plate 14. The above description is directed to the case where the diffusing plate 14, the diffusing film 15, and the lens sheet 16 are separate and individual, but may be used instead, for example. One of the functions of the light collected after the light is diffused is diffused, and 20 sets of light are collected. (5) In order to achieve a thinner device, in Fig. 3, if the distance d between the lamp 2〇 and the light refraction piece 13 is reduced, The area in which the direct light of the lamp 2 is emitted is narrowed, which contributes to uneven brightness. Therefore, with the configuration of the following modification, even if the device is made thinner, uneven brightness can be suppressed. 200823565 Fig. 8 is a cross-sectional view showing the configuration of a backlight unit of a modification. In the figure, the auxiliary diffusion sheet 19 may be disposed in the space between the lamp 20 and the front panel 18. Thereby, since the direct light intensity of the lamp 2 can be reduced, the distance d can be reduced, and the device can be realized. 5 (6) In the above, the glass bulb for the lamp 20 is illustrated as an elliptical cross section perpendicular to the tube axis as shown in Fig. 7(b), but is not limited thereto, and 2 is long. The shape of the inner diameter and the short inner diameter may be any shape. Fig. 9 is a cross-sectional view of the hot cathode type discharge lamp of the modification. For example, as shown in Fig. 9(a), The flat shape, as shown in Fig. 9 (1), can also be rectangular. In this case, since the long inner diameter 〇1 has a large inner diameter 〇, the length of the electrode coil in the axial direction can be increased. Further, by disposing the glass bulb of the lamp 2 with the short inner diameter C2 perpendicular to the liquid crystal panel surface, the thickness of the device can be reduced. ^ (7) In the above, the glass bulb for the lamp 2 is externally viewed. The linear shape 15 is flexible, but it is not limited thereto. For example, the glass bulb of the lamp 2 can also be viewed as a U-shape or a 3-shaped shape. In addition, the glass bulb of the lamp 20 can also be in a ring shape, and the reticle of the light refracting sheet must be arranged in parallel with the axis of the glass bulb and annularly when viewed from a plane. The brightness is uneven. 0 (8) In the case of Shangcai's use of argon and helium as a buffer for rare gases, it can be filled with helium or gas. Because of the large atomic weight of the gas, it can be suppressed on the electrode coil. Since the emitter is scattered, the life can be further increased by filling in the gas. (9) In the above description, the protective film 24 is formed on the inner surface of the glass bulb 22, 21 200823565, but the protective film 24 may not be formed. The description of the light source using the hot cathode type discharge lamp as the backlight unit is not limited thereto. For example, instead of the hot cathode type discharge lamp, a cold cathode type discharge lamp, an external electrode type discharge lamp or other 5 discharges may be used. The lamp serves as a light source for the backlight unit. Further, instead of a general discharge lamp, a linear light source such as an LED or a bulb may be arranged in a line. At this time, it is also the same apparatus as the above according to the present invention, and even if the number of lamps is small, unevenness in brightness can be improved. (11) In the above, the backlight unit is exemplified as the illumination device, but the present invention is not limited thereto, and may be, for example, a housing and a hot cathode type discharge lamp of the embodiment disposed in the housing. General lighting unit. (12) In the above, the liquid crystal display device is described as an example of a display device. However, the present invention is not limited thereto, and may be, for example, a housing and a hot cathode discharge lamp of the embodiment disposed in the housing. The kanban device is mounted as a display device 15. [Industrial Applicability] The present invention is widely applicable to lighting devices and display devices. Further, the present invention can provide an illumination device and a display device capable of suppressing uneven brightness even when the number of lamps of the light source is small, so that the industrial use value is extremely high. [Brief Description of the Drawings] Fig. 1 is a view showing a liquid crystal display device of the present invention in which a part of the liquid crystal display device of the present invention is missing. Fig. 2 is a schematic perspective view showing the structure of the backlight unit 5 for a liquid crystal display of the screen ratio 16:9 of the present embodiment. 22 200823565 Figure 3 is a cross-sectional view taken along line A-A of Figure 2. Fig. 4 is a cross-sectional view showing the backlight unit of the light refraction sheet 13. Fig. 5 is a cross-sectional view of the backlight unit illustrating the function of the light refraction sheet 13. 5 Fig. 6 is a graph showing the luminance distribution characteristics of the backlight unit. Fig. 7 is a view showing the structure of the hot cathode type discharge lamp 20 of the present embodiment, and Fig. 7(a) is a plan sectional view, and Fig. 7(b) is cut in a section B-B in Fig. 7(a). Cross-sectional view of the break. Fig. 8 is a cross-sectional view showing the configuration of a backlight unit of a modification. 10 Fig. 9(a) and Fig. 9(b) are cross-sectional views of a hot cathode type discharge lamp according to a modification. [Description of main component symbols] 1: Liquid crystal display device 13b···Triangle 稜鏡3·.·Liquid crystal panel unit 13b...Acrylic resin layer 4...Main body 14...Diffuser plate 5...Backlight unit 15···Diffusion sheet 6 ...昼面16" lens sheet 10...frame 17...polarizer 11...inner surface 18...front panel 12...auxiliary reflector 19···air layer 13...light refraction sheet 19...auxiliary Diffusion sheet 13a.·· flat layer 20...light 13a...poly S is intended to be resin layer 21...mercury 23 200823565 22...glass bulb 34a, 34b...tubular glass 24···protective film Cl...long Diameter 26...phosphor layer C2...short inner diameter 28...exhaust pipe T".column 30a,30b...electrode 01...incident angle 31, 31a, 31b··.electrode coil 02.. .ejection angles 32a, 32b, 33a, 33b... wire d···distance 24