200905718 九、發明說明 【發明所屬之技術領域】 本發明是關於使用於液晶電視或個人電腦的放電燈及 後照光。 【先前技術】 現在’作爲使用於液晶電視等的光源，使用著冷陰極 螢光燈。冷陰極螢光燈’一般將引出線被連接於杯狀電極 的電極支架封裝，於玻璃燈泡的兩端所成。 對於該冷陰極螢光燈，如日本特開2006-294593號公 報（以下稱爲專利文獻1)或日本特開2006-3 5 1 460號公報 (以下稱爲專利文獻2 )，開發了在玻璃燈泡的兩端部具有 與引出線接合的供電端子的冷陰極營光燈。該供電端子是 以焊料等所形成，藉由以導電性燈座來夾持供電端子部 分’而具有機械性且電性地連接燈的優點。 專利文獻1 :日本特開2006-2945 93號公報 專利文獻2:日本特開2006-351460號公報 【發明內容】 然而，發生引出線與焊料層的接觸不良等的不方便。 此爲有焊料未能放在引出線，或是針孔發生在引出線與焊 料層之間的情形成爲原因。又，增長從玻璃燈泡所導出的 引出線尺寸，而增加與焊料的接觸面積來改善焊料的附著 情形，惟在該方法，惟在引出線與焊料層的接觸並不確 -4- 200905718 實’又，全長度會變長。 本發明的目的是在於提供印制引出線與焊料層的接觸 不良的放電燈及後照光。 爲了達成上述目的，本發明的放電燈，其特徵爲具 備：在內部具有放電空間的放電容器，及配置於上述放電 空間內的電極，及封裝於上述放電容器的端部，一端是被 連接於上述電極，另一端是被導出於上述放電容器的外部 的引出線’及與上述引出線導通般地形成於上述放電容器 的外端部的焊料層’在上述引出線與上述放電容器之間形 成有間隙，而在上述間隙流入有焊料。 依照本發明，可抑制引出線與焊料層的接觸不良。 【實施方式】 (第1實施形態） 以下’針對於本發明的實施形態的放電燈參照圖式加 以說明。第1圖是表示用以說明本發明的第1實施形態的 放電燈的斷面圖，第2圖是表示用以說明本發明的第1實 施形態的放電燈的外觀圖。 本實施形態的放電燈’是例如藉由硼矽酸玻璃等的軟 質玻璃所成的玻璃燈泡1形成有放電容器，在其玻璃燈泡 1的內部形成有放電空間1 1。在放電空間1 1封入有氖Ne 與氬A r的混合氣體所成的稀有氣體與水銀η g。在玻璃燈 泡1的內面’例如形成有RGB的3波長螢光體所成的螢 光體層2。 -5- 200905718 在玻璃燈泡1的兩端部，封裝有電極支架3。電極支 架3是由玻璃珠4，電極5及引出線6所構成。 玻璃珠4是例如與玻璃燈泡1相同的軟質玻璃所構 成，氣密封裝於玻璃燈泡1兩端的放電空間11側。電極 5是例如鎳Ni所成的有底開口狀’而其開口爲玻璃燈泡1 的中央側，底部成爲端部側般地相對配置於放電空間11 的兩端部。引出線6是由內部引出線61與外部引出線62 所構成，此些是藉由接合部7被連接’而被封裝於玻璃燈 泡1與玻璃珠4。又，內部引出線61是被連接於電極5， 而外部引出線62是從玻璃燈泡1的兩端被導出到外部。 又，內部引出線61是可使用科瓦鐵錬钻合金（Kovar)，銅 Mo等接近於玻璃燈泡1的熱脹係數的金屬，而外部引出 線62是可使用銅包鎳鐵線（duniet wire)等導電性高，容易 切斷的金屬。 在玻璃燈泡1端部的外表面’作爲供電部形成有焊料 層8，與外部引出線62電性地被連接。焊料層8的軸方 向的形成領域’端部側爲一直到覆蓋從玻璃燈泡1所突出 的外部引出線6 2的位置較佳，而中央側是一直到端部側 的位置，不超過電極5的前端部’例如1 · 〇mm左右較 佳。又，作爲焊料層8，可使用與玻璃適應良好的錫，錫 與銦的合金，錫與鉍的合金’鍊’鋅’鋁等的材料。又， 在玻璃燈泡1的焊料層8的形成預定部分’若事先噴鋁微 粒子而噴射加工表面，則可更提高焊料的適應。 又，焊料層8是藉由超音波焊料浸漬法所形成較佳。 -6- 200905718 超音波焊料浸漬法是指如日本特開2 0 0 4 · 1 4 6 3 5 1號公報所 述地’ 一面施加超音波振動一面進行焊接的方法，乃爲了 對於玻璃及金屬更容易進行焊料附著。又，因使用超音波 焊料浸漬法’就可將空氣從下述的間隙9排出至外部，因 此可確實且穩定地流進焊料。又，藉由空化作用除去藉由 電極支架3對於玻璃燈泡1的封裝工程時的熱所產生的外 部引出線62的氧化膜或鏽。 在此，一面參照第3圖一面詳述放電燈的端部構造。 弟3圖表不弟1圖的一點鍵線部分的擴大圖。 由該圖可知’在以焊料層8所覆蓋的玻璃燈泡1沿著 外部引出線62及接合部7形成有間隙9，該間隙9是以 焊料塡滿。亦即，間隙9是如第3圖所示地，具有從位於 玻璃燈泡1的管軸方向的最外側的端部一直到接觸部的深 度D。 流到間隙9的焊料層8，是此形成於外部引出線62 的突出部分的焊料層8還增加接觸面積之故，因而接觸變 成牢固，而可減低引出線6與焊料層8的接觸不良。又， 因可增加引出線6與焊料層8的接觸面積，因此在與習知 相同程度的接觸強度也可縮短外部引出線62的突出長 L，而可成爲燈的小型化。在此，流進間隙9的焊料與引 出線6的軸方向的接觸長μ是0.05mm以上，1 .Omm以下 較佳。此爲若接觸長Μ是比0.0 5 m m還小。則焊料的流入 效果變少，相反地，若比1 .Omm還大，則應力施力□於燈 泡端部之際會有玻璃破裂的可能性變高。又，間隙9的深 -7- 200905718 度D是0.10mm以上，0.50mm以下更佳。 是在玻璃燈泡1端部的封裝工程中，藉由 1 1的壓力，封裝場所，封裝條件，或是製 由在機械式方法進行切削就可形成所期望的 又，如圖所示地，將引出線6的接合部 較佳。此爲，因接合部7爲朝玻璃燈泡1的 拔形狀（內部引出線61的直徑Rl>外部引tt R2)，因此可容易確保增大與玻璃燈泡1之 焊料的流入容易程度，將接觸狀態保持在良 間隙9的面積S是0.0002mm2以上，1.0mm 以下表示本發明的放電燈的實施例的一 玻璃燈泡1 :硼矽酸玻璃，內徑：2. 3.4mm，全長：約 950mm。 放電媒體：氖Ne +氬Ar’水銀Hg， 螢光體層2: 3波長螢光體， 玻璃珠4 :硼砂酸玻璃， 電極5 :鎳N i，杯狀， 內部引出線 61 :科瓦鐵鎳鈷合金 0.8mm， 外部引出線62 :杜美線，直徑R2 : 0 L: 1.0mm’接合部7.接合長.〇.6mm’ 焊料層：錫與銦的合金，軸方向形成 觸長 M = 〇.2mm ’ 間隙9 :深度D = 0 _ 2 m m ’面積S : 0 · 0 1 η 在此，間隙9 調整放電空間 作燈之後，藉 深度、大小。 7位於間隙9 端部變細的推 丨線6 2的直徑 間隙。又，由 好的觀點上， 2以下較佳。 規格。 4mm，外徑： ，直徑 R1 : -6mm，突出長 長=7 . Omm，接 nm2 〇 -8- 200905718 上述實施例的燈與未形成間隙9的習知的燈的依引出 線與焊料層的接觸不良的良率，是實施例爲〇. 1 %，而習 知例爲2〜3 % ’可知比習知顯著地改善接觸不良。又，在 引出線6的切斷工程中’藉由其切斷精度的參差不齊，全 突出長L會參差不齊’而在極端情形^突出長L爲也有 成爲大約0mm的情形’惟在該情形下，藉由間隙9，爲 了可確保引出線6與焊料層8的接觸長而不會成爲接觸不 良’接合狀態是良好。當然，在突出長L充分長時，也可 得到效果。 因此’在第1實施形態中，在與外部引出線62導通 般地將焊料層8形成於玻璃燈泡1的外端部的放電燈中， 在外部引出線62與玻璃燈泡1之間形成間隙9，而藉由 在其間隙9流進焊料，就可減低引出線6與焊料層8的接 觸不良。又，因增加引出線6與焊料層8的接觸面積，因 此即使與習知相同程度的接觸強度，也可縮短外部引出線 62的突出長L，而燈的小型化成爲可能。又，藉由超音波 焊料浸漬法形成焊料層8，可確實且穩定地流進焊料，而 且藉由空化作用’可除去外部引出線62的氧化膜或鏽。 又，藉由將流入到間隙9的焊料與引出線6的軸方向 的接觸長Μ作成0.05mm以上，1 .0mm以下，則可確保不 容易發生接觸不良的接觸面積，而且可防止依應力的玻璃 的破裂。 又，藉由將內部引出線6 1與外部引出線6 2的接合部 7位於間隙9，可確保與玻璃燈泡1之間隙9較大之故， -9- 200905718 因而成爲容易流進焊料。又’接合部7是由內部引出線 61與外部引出線62的合金所構成之故，因而一般爲焊料 不容易附著的部分，惟藉由在間隙9欲流進焊料的作用， 在該接合部7也可良好地保持與焊料的接觸狀態。 (第2實施形態） 第4圖是表示針對於本發明的第2實施形態的後照光 加以說明所用的全體圖。 後照光的筐體是由例如白色塑膠所成的前框1 〇 1與後 框1 02所構成。在前框1 0 1，形成有用以取代出光的開口 部1 011，而在該開口部1011以提昇亮度或抑制亮度不均 勻作爲目的，配置有擴散板，擴散片，透鏡片等的光學構 件1 03。後框1 02是有底開口形狀，而在其內表面是黏貼 反射片等而具有高反射性。 在後框1 02的底部，作爲燈保持構件配置有一對燈頭 104a，104b。又，在燈頭 104a，104b，保持著形成於放 電燈1 0 5的兩端的焊料層8。在此，燈頭1 0 4 a，1 0 4 b是 以具有導電性且彈性的金屬，例如銅合金所形成之故，因 而可將放電燈1 〇 5機械性且電性地加以連接保持。 因此，在第2實施形態中，藉由燈頭1 〇 4 a，1 0 4 b來 保持焊料層8，而可容易地進行放電燈1 〇 5的機械性且電 性連接。又’本實施形態的放電燈I 0 5，是即使作成引出 線6的突出長L比間隙9還短，也可維持與焊料層8的充 分的接觸強度之故，因而可縮短放電燈1 05的軸方向長 -10- 200905718 度。亦即，放電燈〗0 5的無效發光長變短之故，因而可較 寬地確保後照光的開口部1 0 1 1，而可實現窄圖框的後照 光。 又’本發明的實施形態是並不被限定於上述者，例如 也可變更成如下。 玻璃燈泡1與引出線6的周圍的接觸部，是形成於被 封裝於玻璃燈泡1的端部的玻璃珠4也可以，這時候玻璃 燈泡1是不會與引出線6的周圍接觸之故，因而在玻璃燈 泡1與引出線6之間形成有間隙9。 電極支架3的玻璃珠4並不是必須，而是無珠構造也 可以。 引出線6是並不一定如第1實施形態地以2以上的金 屬所構成，而如第5圖所示地以一金屬所構成也可以。這 時候，適用於鎳N i等的封裝，且適用切斷不困難的金 屬。 又，在引出線8形成前’藉由噴砂加工從玻璃燈泡1 所突出的引出線部分作成粗面狀態也可以。藉由此，顯著 地提昇突出部分與焊料的接觸強度。又，可除去表面的氧 化層。又，作爲其突出部分的粗面狀態，平均粗糙度Ra 爲ΙΟμιη〜60μηι左右較佳。 如第6圖所示地，將接合部7配置於玻璃燈泡1的端 部外側也可以。一般’在該構成中’接合部7是焊料不容 易附著的部分之故’因而容易發生接觸不良的情形’而藉 由本發明可避免接觸不良。又’如第7圖所示地’將焊料 -11 - 200905718 形成較薄時’在減少焊料量下，可減低接觸不良。 在第1實施形態中，僅以焊料層8構成供電部，惟並 不被限定於此’例如第8圖所示地，在玻璃燈泡1的端 部，以裝設有圓筒狀地形成鋼等金屬薄板所成的蓋電極 8 1的狀態形成有焊料層8 2的供電部也可以。這時候，可 防止依焊料剝落所產生的與燈頭！ 04a , 1 〇4b的接觸不 良，而可提昇接觸的可靠性。 間隙9是一直到玻璃珠4也可以。又，在間隙8，不 必完成地塡滿焊料，亦即，深度D >接觸長Μ也可以。 【圖式簡單說明】 第1圖是表示針對於本發明的第1實施形態的放電燈 加以說明所用的斷面圖。 第2圖是表示針對於本發明的第1實施形態的放電燈 加以說明所用的外觀圖。 弟3圖是表不第1圖的一點鍵線部分的擴大圖。 第4圖是表示針對於本發明的第2實施形態的後照光 加以說明所用的全體圖。 第5圖是表示針對於本發明的放電燈的第1變形例加 以說明所用的圖式。 第6圖是表示針對於本發明的放電燈的第2變形例加 以說明所用的圖式。 第7圖是表示針對於本發明的放電燈的第3變形例加 以說明所用的圖式。 -12 - 200905718 第8圖是表示針對於本發明的放電燈的第4變形例加 以說明所用的圖式。 【主要元件符號說明】 1 :玻璃燈泡 2 :螢光體層 3 :電極支架 f 4 :玻璃珠 5 :電極 6 :引出線 6 1 :內部引出線 62 :外部引出線 7 :接合部 8 :焊料層 9 :間隙 ( 103a 、 103b :燈頭 1 0 4 :放電燈 -13-200905718 IX. Description of the Invention [Technical Field] The present invention relates to a discharge lamp and backlight for use in a liquid crystal television or a personal computer. [Prior Art] Now, as a light source used for a liquid crystal television or the like, a cold cathode fluorescent lamp is used. Cold cathode fluorescent lamps generally have lead wires that are connected to the electrode holder of the cup electrode and are formed at both ends of the glass bulb. In the case of the cold cathode fluorescent lamp, in the case of the glass, it is developed in Japanese Laid-Open Patent Publication No. 2006-294593 (hereinafter referred to as Patent Document 1) or JP-A-2006-3 5 460 (hereinafter referred to as Patent Document 2). A cold cathode camping lamp having power supply terminals that are joined to the lead wires at both ends of the bulb. The power supply terminal is formed of solder or the like, and has an advantage of mechanically and electrically connecting the lamp by sandwiching the power supply terminal portion by a conductive socket. [Patent Document 1] Japanese Laid-Open Patent Publication No. 2006-351460. SUMMARY OF THE INVENTION However, inconvenience such as contact failure between the lead wire and the solder layer occurs. This is the case where solder is not placed on the lead wire, or pinholes occur between the lead wire and the solder layer. Moreover, the size of the lead wire derived from the glass bulb is increased, and the contact area with the solder is increased to improve the adhesion of the solder. However, in this method, the contact between the lead wire and the solder layer is not accurate -4-200905718 Also, the full length will become longer. SUMMARY OF THE INVENTION An object of the present invention is to provide a discharge lamp and a backlight which are inferior in contact between a printed lead wire and a solder layer. In order to achieve the above object, a discharge lamp according to the present invention includes a discharge vessel having a discharge space therein, an electrode disposed in the discharge space, and an end portion of the discharge vessel, and one end of which is connected to The other end of the electrode is formed by a lead wire 'extracted from the outside of the discharge vessel and a solder layer ' formed on the outer end portion of the discharge vessel in a manner similar to the lead wire formed between the lead wire and the discharge vessel There is a gap, and solder flows into the gap. According to the present invention, it is possible to suppress contact failure between the lead wires and the solder layer. [Embodiment] (First embodiment) Hereinafter, a discharge lamp according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing a discharge lamp according to a first embodiment of the present invention, and Fig. 2 is an external view showing a discharge lamp according to a first embodiment of the present invention. In the discharge lamp of the present embodiment, a discharge vessel is formed of a glass bulb 1 made of soft glass such as borosilicate glass, and a discharge space 11 is formed inside the glass bulb 1. A rare gas and mercury η g formed by a mixed gas of 氖Ne and argon A r are sealed in the discharge space 1 1 . On the inner surface of the glass bulb 1, for example, a phosphor layer 2 made of RGB three-wavelength phosphor is formed. -5- 200905718 The electrode holder 3 is packaged at both end portions of the glass bulb 1. The electrode holder 3 is composed of glass beads 4, electrodes 5 and lead wires 6. The glass beads 4 are made of, for example, the same soft glass as the glass bulb 1, and are hermetically sealed on the discharge space 11 side of both ends of the glass bulb 1. The electrode 5 is, for example, a bottomed opening formed by nickel Ni, and the opening is the center side of the glass bulb 1, and the bottom portion is disposed at both end portions of the discharge space 11 so as to be the end side. The lead wire 6 is composed of an inner lead wire 61 and an outer lead wire 62, and these are encapsulated in the glass bulb 1 and the glass beads 4 by being joined by the joint portion 7. Further, the internal lead wires 61 are connected to the electrodes 5, and the external lead wires 62 are led out from both ends of the glass bulb 1 to the outside. Further, the inner lead wire 61 is a metal which can use a Kovar, a copper Mo or the like which is close to the thermal expansion coefficient of the glass bulb 1, and the outer lead wire 62 is a copper-coated nickel-iron wire (duniet wire). ) A metal that is highly conductive and easily cut. A solder layer 8 is formed as a power supply portion on the outer surface of the end portion of the glass bulb 1, and is electrically connected to the external lead wire 62. The end portion side of the axial direction of the solder layer 8 is preferably at a position up to cover the outer lead wire 6 2 protruding from the glass bulb 1, and the center side is a position up to the end side, not exceeding the electrode 5 The front end portion is preferably, for example, about 1 mm. Further, as the solder layer 8, a material suitable for tin, a alloy of tin and indium, an alloy of tin and tantalum, a chain of 'zinc' aluminum, or the like can be used. Further, when the aluminum alloy particles are sprayed on the surface to be formed in advance in the predetermined portion □ of the solder layer 8 of the glass bulb 1, the solder can be more adapted. Further, the solder layer 8 is preferably formed by an ultrasonic solder dipping method. -6- 200905718 Ultrasonic solder immersion method is a method of welding while applying ultrasonic vibration as described in Japanese Patent Laid-Open Publication No. 2000-041, for the purpose of glass and metal. Easy solder adhesion. Further, by using the ultrasonic solder dipping method, air can be discharged to the outside from the gap 9 described below, so that the solder can be surely and stably flowed. Further, the oxide film or rust of the external lead wire 62 generated by the heat of the electrode holder 3 for the packaging process of the glass bulb 1 is removed by cavitation. Here, the end structure of the discharge lamp will be described in detail with reference to FIG. The 3rd chart is not an enlarged view of the point of the key line of the 1st figure. As can be seen from the figure, the glass bulb 1 covered with the solder layer 8 has a gap 9 formed along the outer lead wire 62 and the joint portion 7, and the gap 9 is filled with solder. That is, the gap 9 has a depth D from the outermost end portion in the tube axis direction of the glass bulb 1 to the contact portion as shown in Fig. 3. The solder layer 8 flowing to the gap 9 is such that the solder layer 8 formed on the protruding portion of the external lead wire 62 also increases the contact area, so that the contact becomes firm and the contact failure between the lead wire 6 and the solder layer 8 can be reduced. Further, since the contact area between the lead wire 6 and the solder layer 8 can be increased, the contact length L of the external lead wire 62 can be shortened by the contact strength similar to the conventional one, and the lamp can be downsized. Here, the contact length μ of the solder flowing into the gap 9 and the axial direction of the lead wire 6 is preferably 0.05 mm or more, and 1.0 mm or less. This is if the contact length is less than 0.0 5 m. Then, the inflow effect of the solder is small, and conversely, if it is larger than 1.0 mm, there is a possibility that the glass is broken when the stress is applied to the end of the bulb. Further, the depth -7 - 200905718 degrees D of the gap 9 is 0.10 mm or more, and more preferably 0.50 mm or less. In the packaging process of the end of the glass bulb 1, the pressure can be formed by the mechanical pressure method by the pressure of 1 1 , the packaging place, the packaging condition, or the manufacturing method, as shown in the figure, The joint portion of the lead wire 6 is preferred. In this case, since the joint portion 7 has a pull-out shape toward the glass bulb 1 (the diameter R1 of the inner lead wire 61) and the outer lead tt R2, it is easy to ensure an increase in the ease of inflow of the solder to the glass bulb 1, and the contact state is improved. The area S of the good gap 9 is 0.0002 mm 2 or more, and 1.0 mm or less shows a glass bulb 1 of the embodiment of the discharge lamp of the present invention: borosilicate glass, an inner diameter of 2.3.4 mm, and a total length of about 950 mm. Discharge medium: 氖Ne + Argon Ar' mercury Hg, phosphor layer 2: 3 wavelength phosphor, glass beads 4: borax glass, electrode 5: nickel N i, cup, internal lead 61: Kova iron Cobalt alloy 0.8mm, external lead wire 62: Duome wire, diameter R2: 0 L: 1.0mm' joint 7. Joint length. 〇.6mm' Solder layer: alloy of tin and indium, forming the contact length in the axial direction M = 〇.2mm 'Gap 9: Depth D = 0 _ 2 mm 'Area S : 0 · 0 1 η Here, the gap 9 adjusts the discharge space for the light, and the depth and size. 7 The diameter gap of the pusher wire 6 2 which is tapered at the end of the gap 9. Also, from a good point of view, 2 or less is preferred. specification. 4mm, outer diameter: , diameter R1: -6mm, protruding length = 7. Omm, connected to nm2 〇-8- 200905718 The lamp of the above embodiment and the conventional lamp with no gap 9 formed by the lead wire and the solder layer The yield of poor contact is 1. 1% in the examples, and 2 to 3% in the conventional example. It is known that the contact failure is remarkably improved. In addition, in the cutting process of the lead wire 6, 'the unevenness of the cutting precision is uneven, the full length L is uneven, and in the extreme case, the length L is also about 0 mm. In this case, in order to ensure that the contact between the lead wire 6 and the solder layer 8 is long by the gap 9, the contact state is not good. Of course, the effect can also be obtained when the length L is sufficiently long. Therefore, in the first embodiment, the solder layer 8 is formed in the discharge lamp at the outer end portion of the glass bulb 1 as the external lead wire 62 is electrically connected, and a gap 9 is formed between the outer lead wire 62 and the glass bulb 1. By flowing the solder into the gap 9, the contact failure between the lead wire 6 and the solder layer 8 can be reduced. Further, since the contact area between the lead wire 6 and the solder layer 8 is increased, even if the contact strength is the same as that of the conventional one, the protruding length L of the external lead wire 62 can be shortened, and the size of the lamp can be reduced. Further, by forming the solder layer 8 by the ultrasonic solder dipping method, the solder can be surely and stably flowed, and the oxide film or rust of the external lead wire 62 can be removed by the cavitation action. In addition, by making the contact length of the solder flowing into the gap 9 and the axial direction of the lead wire 6 0.05 mm or more and 1.0 mm or less, it is possible to secure a contact area which is less likely to cause contact failure and prevent stress. The rupture of the glass. Further, by arranging the joint portion 7 of the inner lead wire 61 and the outer lead wire 6 2 in the gap 9, it is ensured that the gap 9 with the glass bulb 1 is large, and -9-200905718 becomes easy to flow into the solder. Further, the joint portion 7 is formed of an alloy of the inner lead wire 61 and the outer lead wire 62. Therefore, it is generally a portion where solder does not easily adhere, but the solder is required to flow into the gap 9 at the joint portion. 7 can also maintain good contact with the solder. (Second Embodiment) Fig. 4 is a general view showing the backlight used in the second embodiment of the present invention. The rear light housing is composed of a front frame 1 〇 1 and a rear frame 102 made of, for example, white plastic. In the front frame 101, an opening portion 1 011 for replacing the light is formed, and the optical member 1 such as a diffusion plate, a diffusion sheet, and a lens sheet is disposed for the purpose of improving the brightness or suppressing the brightness unevenness in the opening portion 1011. 03. The rear frame 102 is a bottomed opening shape, and the inner surface thereof is adhered to a reflection sheet or the like and has high reflectivity. At the bottom of the rear frame 102, a pair of bases 104a, 104b are disposed as the lamp holding members. Further, the solder layers 8 formed at both ends of the discharge lamp 105 are held in the bases 104a, 104b. Here, the base 1 0 4 a, 1 0 4 b is formed of a conductive and elastic metal such as a copper alloy, so that the discharge lamp 1 〇 5 can be mechanically and electrically connected and held. Therefore, in the second embodiment, the solder layer 8 is held by the base 1 〇 4 a, 1 0 4 b, and the discharge lamp 1 〇 5 can be easily mechanically and electrically connected. Further, in the discharge lamp I 0 5 of the present embodiment, even if the projection length L of the lead wire 6 is shorter than the gap 9, the sufficient contact strength with the solder layer 8 can be maintained, so that the discharge lamp 105 can be shortened. The axial direction is -10-200905718 degrees. That is, since the ineffective light emission length of the discharge lamp is shortened, the opening portion of the backlight can be secured to the opening portion 1 0 1 1 , and the backlight of the narrow frame can be realized. Further, the embodiment of the present invention is not limited to the above, and may be changed, for example, as follows. The contact portion between the glass bulb 1 and the lead wire 6 may be formed on the glass bead 4 that is enclosed at the end of the glass bulb 1. At this time, the glass bulb 1 does not come into contact with the periphery of the lead wire 6, Thus, a gap 9 is formed between the glass bulb 1 and the lead wire 6. The glass beads 4 of the electrode holder 3 are not necessarily required, but may be a beadless structure. The lead wire 6 is not necessarily composed of a metal of 2 or more as in the first embodiment, but may be formed of a metal as shown in Fig. 5. At this time, it is suitable for a package such as nickel Ni, and is suitable for metal which is not difficult to cut. Further, the lead wire portion protruding from the glass bulb 1 by sandblasting may be formed in a rough state before the lead wire 8 is formed. Thereby, the contact strength of the protruding portion with the solder is remarkably improved. Further, the oxide layer on the surface can be removed. Further, as the rough surface state of the protruding portion, the average roughness Ra is preferably about ιμηη to 60μηι. As shown in Fig. 6, the joint portion 7 may be disposed outside the end portion of the glass bulb 1. In general, the "joining portion 7" is a portion where the solder does not easily adhere, and thus the contact failure is likely to occur, and the contact defect can be avoided by the present invention. Further, when the solder 11 - 200905718 is formed thin as shown in Fig. 7, the contact loss can be reduced by reducing the amount of solder. In the first embodiment, the power supply portion is constituted only by the solder layer 8, but the present invention is not limited thereto. For example, as shown in Fig. 8, a steel is formed in a cylindrical shape at the end of the glass bulb 1. The power supply portion of the solder layer 822 may be formed in a state in which the lid electrode 8 1 made of a thin metal plate is formed. At this time, it is possible to prevent the lamp from being generated by the peeling of the solder! The contact between 04a and 1〇4b is poor, which improves the reliability of contact. The gap 9 is also up to the glass beads 4. Further, in the gap 8, it is not necessary to completely fill the solder, that is, the depth D > BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing a discharge lamp according to a first embodiment of the present invention. Fig. 2 is an external view showing a discharge lamp according to a first embodiment of the present invention. The 3rd figure is an enlarged view showing a part of the key line of the first figure. Fig. 4 is a general view showing the backlight used in the second embodiment of the present invention. Fig. 5 is a view showing a first modification of the discharge lamp of the present invention. Fig. 6 is a view showing a second modification of the discharge lamp of the present invention. Fig. 7 is a view showing a third modification of the discharge lamp of the present invention. -12 - 200905718 Fig. 8 is a view showing a fourth modification of the discharge lamp of the present invention. [Description of main component symbols] 1 : Glass bulb 2 : Phosphor layer 3 : Electrode holder f 4 : Glass bead 5 : Electrode 6 : Lead wire 6 1 : Internal lead wire 62 : External lead wire 7 : Bonding portion 8 : Solder layer 9 : Clearance ( 103a , 103b : Lamp head 1 0 4 : Discharge lamp-13-