Abstract: A hermetically sealed lamp having at least one seal-material-free bond. The seal material-free bond may be a material diffusion bond, a mechanically deformed bond such as a cold weld or crimp, a focused heat bond such as a laser bond, or any other such bond. For example, the hermetically sealed lamp may have one or more endcaps diffusion bonded to an arc envelope, such as a ceramic tube or bulb. The hermetically sealed lamp also may have one or more tubular structures, such as dosing tubes, which are mechanically closed via cold welding or crimping. Localized heating, such as the heat provided by an intense laser, also may be used to enhance any of the foregoing bonds.

Abstract: An electric lamp (1) comprising a gastight lamp vessel (2) for the transformation of electrical energy into light, which lamp vessel has two current conductors (3,6; 4,7) which extend to the outside. The lamp further comprises an outer envelope (9) in which the lamp vessel (2) is arranged with a space between the lamp vessel and the outer envelope. The outer envelope (9) has a lamp cap (11) to which the current conductors (6,7) are electrically connected. The lamp (1) further has means (17) for switching off the lamp by short-circuiting the current conductors (6,7) in the case of fracture of the outer envelope (9).

Abstract: A high pressure discharge lamp includes: a quartz glass bulb having an expanded portion and sealing portions; conductive elements, and a pair of electrodes. The conductive elements are airtightly sealed at the sealing portions of the quartz glass bulb. Each electrode of the pair of electrodes is disposed so as to be opposite the other and each electrode is connected to one of the conductive elements. An angle &thgr;1 between a tangent along the inner surface of the expanded portion at a position 0.5 mm away from an origin of one of the sealing portions along the length direction of each electrode and the direction of the length of each electrode is at least about 40°.

Abstract: A spark plug is provided which comprises a center electrode and a ground electrode having at a free end portion thereof a discharge surface which is opposite to an axial end surface of the center electrode to provide therebetween a spark gap, wherein the center electrode has a center electrode tip forming the axial end surface thereof, the center electrode tip being made of a material containing Ir as a major constituent, and wherein G≦2A+0.5 where G is a spark gap (mm) and A is the distance (mm) between a first imaginary line and a second marginal line.