Patent ID: 7628511

Claim:
A light source device, comprising: an alternating current high-pressure mercury lamp having a pair of electrodes internally arranged opposite each other; a light-emitting part having at least 0.15 mg/mm 3 of mercury, a halogen within a range of 10 −6 μmol/mm 3 to 10 −2 μmol/mm 3 , and hermetically sealed parts extending from both ends of the light-emitting part; a reflecting mirror comprising a concave reflecting part arranged so as to surround the light-emitting part, and a cylindrical neck part; and an adhesive for securing the mercury lamp and the reflecting mirror by filling a periphery of the hermetically sealed parts of the mercury lamp, wherein a distance L 2 (mm) from a center in between the electrodes to the adhesive is set at a value of one of 16 mm or less and 20 mm or greater.