Patent ID: 8690360

Claim:
A lamp unit comprising: a high pressure discharge lamp that includes an envelope having a discharge space therein and a pair of discharge electrodes exposed to the discharge space; a reflector that reflects light emitted from the high pressure discharge lamp and a start-up assist member that assists the high pressure discharge lamp in starting up, wherein the envelope includes a light-emitting part enclosing the discharge space, and a first sealing part and a second sealing part that are connected to the light-emitting part, the first sealing part and the second sealing part each enclose a metal foil, from one end of each metal foil, a corresponding discharge electrode extends into the discharge space, from the other end of each metal foil, an external lead wire extends so as to be partly exposed outside a corresponding sealing part, the start-up assist member includes a first metal wire and a dielectric member, one end of the first metal wire being electrically connected to one of the discharge electrodes of the high pressure discharge lamp, and the dielectric member having relative permittivity higher than relative permittivity of the envelope, the dielectric member is located on an outer surface of one of the first sealing part and the second sealing part, and the one end of the first metal wire is electrically connected to an exposed portion of the external lead wire corresponding to the other one of the first sealing part and the second sealing part, and the other end of the first metal wire and the dielectric member are close to or in contact with each other so that discharge occurs therebetween when a voltage is applied to cause the high pressure discharge lamp to start discharging.