| 摘要 |
PURPOSE:To enable it to moderate excessive force to be generated from expansion and contraction by housing a luminous tube inside an outer tube and fixing a supporting rod made of a high melting point metal to a fastener on one end of the luminous tube while the other end is buried in the outer tube sealing part. CONSTITUTION:A luminous tube 1 having the electrodes 6a, 6b and the sealed-in mercury, metal halogen compound and rare gas is housed in an outer tube 2 made of quarz glass for forming a high pressure discharge lamp. Thereby, the luminous tube 1 is held by the supporting plates 3a and 3b, fasteners 4a and 4b so as not to move in the axial direction while providing a supporting rod 7 made of a high melting point metal, whose one end is welded to the fastener 4b and the other end is buried in the sealing part of the outer tube 2 so as not to move in the axial direction. Accordingly, thermal expansion and contraction of the luminous tube 1 accompanying the switching of a lamp is made to be smoothly performed thus preventing an obstacle in case of possibly applied excessive force. |
