200926250 九、發明說明： 【發明所靥之技術領域】 本發明係有關投影機用光源之超高壓水銀放電燈，更 詳細之，係有關發光管之電極芯線的形狀。 【先前技術】 投影機用光源所使用之超高壓水銀放電燈（以下，亦 有時稱爲燈）的發光管，係將電極系統插入於石英玻璃管 之中，並將該等密封。超高壓水銀放電燈之發光管的內部 壓力非常高，亦有達到200大氣壓的情況。 專利文獻1 :日本專利特開平11 一 0671 56號公報 【發明內容】， [發明所欲解決之課題] 因此，在燈點亮當中，有發光管的石英玻璃管無法承 受內壓而破裂之情形。尤其，電極熔接部之石英玻璃管與 箔之密接性不良而在其間會產生間隙。高壓的水銀會進入 其間隙，而有石英玻璃管破裂之情形。 本發明乃爲解決上述課題而完成者，係提供一種石英 燈泡破裂之虞少，可靠性高的超高壓水銀放電燈爲目的。 [用以解決課題之手段] 有關本發明之超高壓水銀放電燈，係具有將一對電極 系統密封於石英燈泡內之發光管，其特徵爲 —對電極系統，分別具備具有熔接部之電極、和一端 被熔接於熔接部的箔、以及被連接於箔之另一端的導線， 溶接部之與電極的長度方向成正交的剖面形狀’形成 200926250 大致正弦波狀、大致梯形、或大致半圓形，而 把該箔與該熔接部中面積最大的平面部熔接。 有關本發明之超高壓水銀放電燈，具有將一對電極系 統密封於石英燈泡內之發光管，該放電燈之特徵爲 一對電極系統，分別具備具有熔接部之電極、和一端 被熔接於熔接部的箔、以及被連接於箔之另一端的導線， 在熔接部之端部，於該電極的長度方向設置切口，而 將箔插入切口予以熔接。 ❹[發明效果] 有關本發明之超高壓水銀放電燈爲，將與熔接部之電 ，極的長度方向成正交的剖面形狀，形成大致正弦波狀、大 致梯形、或大致半圓形，而藉由把箔與熔接部中面積最大 的平面部熔接，可抑制在密封電極系統時於石英燈泡與箔 或電極之間發生間隙，所以可獲得石英燈泡破裂之虞少， 可靠性高的超高壓水銀放電燈。 【實施方式】 ❹ [發明之最佳實施形態] 實施形態1 第1圖至第6圖係顯示實施形態1之圖’第1圖係將 附有反射鏡之放電燈1的一部剖開的側視圖，第2圖係發 光管2的截面圖，第3圖係電極系統24b之俯視圖（a)與側 視圖（b)，第4圖係電極21b之俯視圖（a)與側視圖（b) ’第5 圖係密封後之熔接部2 1 b _ 2附近的截面圖（（a)爲實施形態 1之一例，（b)爲用以比較而顯示的往例）。 200926250 如第1圖所示，附有反射鏡之放電燈1 (超高壓水銀 放電燈的一例）係將發光管2收納在反射鏡3的內部。發 光管2的發光部分，係位於球面、橢圓面、拋物面等碗狀 之反射鏡3的焦點。被放射之光，係透過施作於反射鏡3 之內面的反射膜反射，而被放射到燈的前方。被放射之光 係射入到設置在燈前方的光學系。 如第2圖所示，發光管2，係一對的電極系統24a及 電極系統24b被配置在石英燈泡20內。電極系統24a，係 具備有：電極21a、箔22a、導線23a。同樣地，電極系統 24b，係具備有：電極21b、箔22b、導線23b。在發光管2 內，封入水銀及稀有氣體。而且，發光管2的兩端部，係 透過將石英燈泡20加熱、熔融而被密封。 藉由第3圖，將電極系統24a及電極系統24b的構成， 以電極系統24b爲例作說明。電極系統24a之構成也與電 極系統24b相同。 如第3圖所示，電極系統24b，係具有：電極21b;箔 22b，藉由熔接固定於該電極21b的一端部；及導線23b， 藉由熔接固定於該箔22b的另一端部。箔22b與導線23b 的材料爲鉬。箔22b係使用厚度非常薄大致爲數十微米左 右者，由於使箔22b變薄所以可提與高石英燈泡20間的密 接性，使氣密性變好。 如第4圖所示，電極21b，係於芯線21b - 4之一方的 端部形成放電部21b— 1。芯線21b— 4之另一方的端部成 爲箔2 2b會被熔接的熔接部21b - 2。在本實施形態，係熔 200926250 接部21b- 2的形狀具有特徵。以往被使用於發光管的電極 爲，熔接部的截面形狀是圓形。本實施形態的熔接部21b 一 2,係如第4(b)圖所示’其截面形狀並非圓形，而大致爲 正弦波狀（以頂點爲中心之一循環份）、大致爲梯形、或大 致爲半圓形等。截面形狀爲大致正弦波狀、大致梯形、或 大致半圓形的熔接部21b - 2之面積最大的平面部被熔接 於箔22b。關於持有如此形狀的熔接部21b-2之電極21b 的作用，將在說明發光管2的製造過程之後再作敘述。雖 〇 未圖示，但電極21a亦具備有熔接部21a — 2。 熔接部2 1 b - 2之截面形狀爲大致正弦波狀的情况，面 積最大的平面部係以頂點爲中心之一循環份的底邊。 溶接部2 1 b - 2之截面形狀爲大致梯形的情况，面積最 大的平面部爲底邊。 熔接部21b-2之截面形狀爲大致半圓形的情况，面積 最大的平面部爲截面是直線部分的面。 關於持有截面形狀是大致正弦波狀、大致梯形、或大 〇 致半圓形的溶接部21b— 2之電極21b的作用茲說明如下。 在密封過程方面，熔接部21b_2的截面形狀，例如， 第5(b)圖所示之圓形的情况，如該圖所示，在熔接部2lb -2與箔2 2b之接觸部附近，熔融的石英玻璃無法到達， 而產生間隙26。若高壓水銀進入此間隙26時石英燈泡2〇 有破裂之虞。 本實施形態之熔接部2 1 b - 2之截面形狀形成大致正 弦波狀、大致梯形、或大致半圓形，所以如第5 (a)圖所示， 200926250 在熔接部2 1 b — 2之截面形狀爲圓形的情况所產生的間隙 26部分因爲有熔接部21b-2存在，所以不會發生間隙26。 因此’可提供石英燈泡20破裂之虞變少且可靠性高的超高 壓水銀放電燈。 實施形態2 第6圖係顯示實施形態2的圖，（a)爲顯示電極21b之 形狀的俯視圖、（b)爲電極系統24b的俯視圖、（c)爲密封後 之熔接部21b— 2附近的截面圖。 如第6(a)圖所示，在電極21b的溶接部21b— 2，於其 圓形之截面的大致中心附近，在芯線21a - 4的長度方向設 置有切口 2 7。 ， 如第6(b)圖所示，將箔2 2b插入切口部分予以熔接。 如第6(c)圖所示，在密封後的熔接部21b_2附近，箔 2 2b及熔接部21b — 2和石英燈泡20之間不會發生間隙26。 以上，雖說明有關電極21b，但關於電極21a也是同 樣。 如此，在電極21a、21b的熔接部21a-2、21b— 2，於 其圓形之截面的大致中心附近，在芯線21a — 4、21b— 4的 長度方向設置切口 27，而藉由將箔22b插入切口部分予以 熔接，在密封後的熔接部21a— 2、21b— 2附近，箔22a、 22b及熔接部21a— 2、21b— 2和石英燈泡20之間不會發 生間隙26，因此，可提供石英燈泡20破裂之虞變少，可 靠性高的超高壓水銀放電燈。 200926250 放 之 鏡 射 反 有 附 將 爲 圖 之 ο 態圖 形視 施側 實的 1 示開 明顯剖 說係部 單圖一 簡 1 的 式第1 圖 燈 [ 電 第2圖係顯示實施形態1之圖，爲發光管2的截面圖。 第3圖係顯示實施形態1之圖，爲電極系統2 4b的俯 視圖（a)與側視圖（b)。 第4圖係顯示實施形態1之圖，爲電極2 1 b的俯視圖 (a)與側視圖（b )。 Ο 第5圖係顯示實施形態1之圖，爲密封後之熔接部21b - 2附近的截面圖（（a)爲實施形態1的一例，（b)爲用以比較 而顯示的往例）。 ， 第6圖係顯示實施形態2之圖，（a)爲顯示電極21b之 形狀的俯視圖、（b)爲電極系統24b的俯視圖、（c)爲密封後 之熔接部21b— 2附近的截面圖。 【主要元件符號說明】 1 附有反射鏡之放電燈 2 發光管 3 反射鏡 20 石英燈泡 2 1 a > 2 1b 電極 2 1a- 1、2 1b- 1 放電部 2 1a- 2、21b — 2 熔接部 2 1a — 3 線圈 2 1a- 4、2 1b- 4 芯線 Ο -10- 200926250 22a 、 22b 23a 、 23b 24a 、 24b 26 箔 導線 電極系統 間隙200926250 IX. Description of the Invention: [Technical Field] The present invention relates to an ultrahigh pressure mercury discharge lamp for a light source for a projector, and more particularly to a shape of an electrode core of an arc tube. [Prior Art] An arc tube of an ultrahigh pressure mercury discharge lamp (hereinafter sometimes referred to as a lamp) used for a light source for a projector is obtained by inserting an electrode system into a quartz glass tube and sealing the same. The internal pressure of the arc tube of the ultra-high pressure mercury discharge lamp is very high, and it also reaches 200 atmospheres. [Problem to be Solved by the Invention] Therefore, in the case where the lamp is turned on, the quartz glass tube having the arc tube cannot be subjected to internal pressure and is broken. . In particular, the quartz glass tube of the electrode fusion portion is inferior in adhesion to the foil, and a gap is formed therebetween. High-pressure mercury enters the gap and there is a crack in the quartz glass tube. The present invention has been made to solve the above problems, and an object of the present invention is to provide an ultrahigh pressure mercury discharge lamp having a low breakdown of a quartz bulb and a high reliability. [Means for Solving the Problem] The ultrahigh pressure mercury discharge lamp of the present invention has an arc tube in which a pair of electrode systems are sealed in a quartz bulb, and is characterized in that the counter electrode system is provided with an electrode having a welded portion, And a foil having one end welded to the welded portion and a lead wire connected to the other end of the foil, and the cross-sectional shape of the welded portion orthogonal to the longitudinal direction of the electrode is formed to be substantially sinusoidal, substantially trapezoidal, or substantially semicircular in shape. The foil is welded to the flat portion having the largest area among the welded portions. An ultrahigh pressure mercury discharge lamp according to the present invention has an arc tube in which a pair of electrode systems are sealed in a quartz bulb. The discharge lamp is characterized by a pair of electrode systems each having an electrode having a welded portion and one end welded to the welded portion. The foil of the portion and the wire connected to the other end of the foil are provided with slits in the longitudinal direction of the electrode at the end of the welded portion, and the foil is inserted into the slit to be welded. ❹ [Effect of the Invention] The ultrahigh-pressure mercury discharge lamp according to the present invention has a cross-sectional shape orthogonal to the longitudinal direction of the electric pole of the welded portion, and is formed in a substantially sinusoidal shape, a substantially trapezoidal shape, or a substantially semicircular shape. By welding the foil to the flat portion having the largest area in the welded portion, it is possible to suppress a gap between the quartz bulb and the foil or the electrode when the electrode system is sealed, so that the quartz bulb can be broken and the high-reliability ultra-high voltage can be obtained. Mercury discharge lamp. [Embodiment] 最佳 BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 FIG. 1 to FIG. 6 are views showing a first embodiment. FIG. 1 is a section of a discharge lamp 1 with a mirror attached thereto. Side view, Fig. 2 is a cross-sectional view of the arc tube 2, Fig. 3 is a plan view (a) and a side view (b) of the electrode system 24b, and Fig. 4 is a plan view (a) and a side view (b) of the electrode 21b The fifth drawing is a cross-sectional view of the vicinity of the welded portion 2 1 b _ 2 after sealing ((a) is an example of the first embodiment, and (b) is a conventional example for comparison). 200926250 As shown in Fig. 1, a discharge lamp 1 (an example of an ultrahigh pressure mercury discharge lamp) with a mirror is used to house the arc tube 2 inside the mirror 3. The light-emitting portion of the light-emitting tube 2 is located at the focus of the bowl-shaped mirror 3 such as a spherical surface, an elliptical surface, or a paraboloid. The emitted light is reflected by the reflection film applied to the inner surface of the mirror 3, and is radiated to the front of the lamp. The emitted light is incident on the optical system disposed in front of the lamp. As shown in Fig. 2, the arc tube 2, the pair of electrode systems 24a and the electrode system 24b are disposed in the quartz bulb 20. The electrode system 24a is provided with an electrode 21a, a foil 22a, and a lead wire 23a. Similarly, the electrode system 24b is provided with an electrode 21b, a foil 22b, and a wire 23b. In the arc tube 2, mercury and a rare gas are sealed. Further, both end portions of the arc tube 2 are sealed by heating and melting the quartz bulb 20. The configuration of the electrode system 24a and the electrode system 24b will be described by taking the electrode system 24b as an example. The configuration of the electrode system 24a is also the same as that of the electrode system 24b. As shown in Fig. 3, the electrode system 24b has an electrode 21b, a foil 22b fixed to one end portion of the electrode 21b by fusion welding, and a lead wire 23b fixed to the other end portion of the foil 22b by fusion bonding. The material of the foil 22b and the wire 23b is molybdenum. The foil 22b is formed to have a very thin thickness of approximately several tens of micrometers. Since the foil 22b is made thinner, the adhesion to the high quartz bulb 20 can be improved, and the airtightness can be improved. As shown in Fig. 4, the electrode 21b is formed at one end of the core wire 21b-4 to form a discharge portion 21b-1. The other end of the core wire 21b-4 is a welded portion 21b-2 in which the foil 2bb is welded. In the present embodiment, the shape of the joint portion 21b-2 of the fusion portion 200926250 is characterized. Conventionally, the electrode used in the arc tube has a circular cross section. The welded portion 21b-2 of the present embodiment has a cross-sectional shape that is not circular but has a substantially sinusoidal shape (one cycle centered on the apex), a substantially trapezoidal shape, or a cross-sectional shape as shown in Fig. 4(b). It is roughly semi-circular and the like. The flat portion having the largest cross-sectional shape of a substantially sinusoidal shape, a substantially trapezoidal shape, or a substantially semicircular welded portion 21b-2 is welded to the foil 22b. The action of the electrode 21b holding the welded portion 21b-2 having such a shape will be described after explaining the manufacturing process of the arc tube 2. Although not shown, the electrode 21a is also provided with a welded portion 21a-2. The cross-sectional shape of the welded portion 2 1 b - 2 is substantially sinusoidal, and the flat portion having the largest area is the bottom side of one of the vertices. The cross-sectional shape of the welded portion 2 1 b - 2 is substantially trapezoidal, and the flat portion having the largest area is the bottom side. The cross-sectional shape of the welded portion 21b-2 is substantially semicircular, and the flat portion having the largest area is a surface having a straight portion in cross section. The action of the electrode 21b having the welded portion 21b-2 having a substantially sinusoidal shape, a substantially trapezoidal shape, or a substantially semicircular shape is described below. In the sealing process, the cross-sectional shape of the welded portion 21b_2, for example, the circular shape shown in Fig. 5(b), as shown in the figure, is melted near the contact portion of the welded portion 2lb-2 and the foil 2 2b. The quartz glass cannot be reached, and a gap 26 is created. If the high-pressure mercury enters the gap 26, the quartz bulb 2 has a crack. The cross-sectional shape of the welded portion 2 1 b - 2 of the present embodiment is substantially sinusoidal, substantially trapezoidal, or substantially semicircular. Therefore, as shown in Fig. 5 (a), 200926250 is in the welded portion 2 1 b - 2 The portion of the gap 26 which is formed when the cross-sectional shape is circular is partially formed by the welded portion 21b-2, so that the gap 26 does not occur. Therefore, an ultrahigh pressure mercury discharge lamp in which the quartz bulb 20 is broken and has high reliability can be provided. (Embodiment 2) Fig. 6 is a view showing a second embodiment, wherein (a) is a plan view showing the shape of the electrode 21b, (b) is a plan view of the electrode system 24b, and (c) is a vicinity of the welded portion 21b-2 after sealing. Sectional view. As shown in Fig. 6(a), in the vicinity of the substantially center of the circular cross section of the welded portion 21b-2 of the electrode 21b, a slit 27 is provided in the longitudinal direction of the core wire 21a-4. As shown in Fig. 6(b), the foil 22b is inserted into the slit portion to be welded. As shown in Fig. 6(c), the gap 26 does not occur between the foil 22b and the welded portion 21b-2 and the quartz bulb 20 in the vicinity of the sealed welded portion 21b_2. Although the electrode 21b has been described above, the same applies to the electrode 21a. As described above, in the welded portions 21a-2 and 21b-2 of the electrodes 21a and 21b, slits 27 are provided in the longitudinal direction of the core wires 21a-4, 21b-4 in the vicinity of the substantially center of the circular cross section, and the foil is formed by the foil 22b is inserted into the slit portion to be welded, and no gap 26 occurs between the foils 22a, 22b and the welded portions 21a-2, 21b-2 and the quartz bulb 20 in the vicinity of the sealed welded portions 21a-2, 21b-2, and therefore, It can provide ultra-high pressure mercury discharge lamps with less rupture of quartz bulb 20 and high reliability. 200926250 The reflection of the mirror is reflected in the figure. The state of the figure is shown in the figure. The figure is shown in the figure. The figure 1 is the figure of the figure 1. The figure 2 shows the embodiment 1. The figure is a cross-sectional view of the arc tube 2. Fig. 3 is a view showing the first embodiment, showing a top view (a) and a side view (b) of the electrode system 24b. Fig. 4 is a view showing the first embodiment, showing a plan view (a) and a side view (b) of the electrode 2 1 b. Fig. 5 is a view showing the first embodiment, showing a cross-sectional view of the vicinity of the welded portion 21b-2 after sealing ((a) is an example of the first embodiment, and (b) is a conventional example for comparison). Fig. 6 is a view showing a second embodiment, wherein (a) is a plan view showing the shape of the electrode 21b, (b) is a plan view of the electrode system 24b, and (c) is a cross-sectional view of the vicinity of the welded portion 21b-2 after sealing. . [Main component symbol description] 1 Discharge lamp with mirror 2 Illuminating tube 3 Mirror 20 Quartz bulb 2 1 a > 2 1b Electrode 2 1a- 1, 2 1b- 1 Discharge part 2 1a- 2, 21b — 2 Welding joint 2 1a - 3 coil 2 1a - 4, 2 1b - 4 core wire -10- -10- 200926250 22a , 22b 23a , 23b 24a , 24b 26 foil wire electrode system gap
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