PROBLEM TO BE SOLVED: To improve the heat dissipation effect in an arc tube array type light source device using gas discharge and to enhance the reliability of operation. In an arc tube array type light source device composed of a glass thin tube filled with a discharge gas, a bottom surface of each arc tube is partially attached to an electrode substrate on which a plurality of arc tubes are mounted in parallel and supported on the upper surface. An exposed slit was provided so that the arc tube could be directly cooled. [Selection diagram] Fig. 3【課題】ガス放電を利用した発光管アレイ型光源装置における放熱効果の向上を図り、動作の信頼性を高めること。【解決手段】放電ガスを封入したガラス細管から成る発光管アレイ型光源装置において、上面に複数本の発光管１１を平行に載置して支持する電極基板に各発光管の底面を部分的に露出するスリットを設けて、発光管を直接冷却できるようにした。【選択図】図３
