LIGHT SOURCE DEVICE

PURPOSE:To prevent an electrically active part from being directly touched when exchanging a lamp, and to miniaturize the device by simplifying the insulating construction of a transformer by making an interlocking switch unnecessary. CONSTITUTION:A first lamp exchange hatch 30 and a second lamp exchange hatch 33 which are attached and detached when the lamp is exchanged, are provided to the light source device 21. The second lamp exchange hatch 33 is constituted with an approximately L shaped insulation member so that the front surface of a lamp unit 32 consisting of a xenon lamp 22 and a heat sink 23 is covered and in its rear part of the top surface part, a conductive pattern 35 is provided. Although a starter and a lamp unit 32 are electrically connected by having the conductive pattern 35 engaged to an electrode separator part 36, the conductive pattern 35 is extracted when the second lamp exchange hatch 33 is removed and the circuit feeding the power to both electrodes of the lamp in the electrode separator part 36 is separated while keeping a space in between which is more than the specified insulating distance.