Patent ID: 8773008

Claim:
A discharge lamp bulb comprising an arc tube including: a luminous tube, both ends of which are sealed; a pair of electrodes that are disposed inside the luminous tube so as to be opposed to each other; an outer tube that has the luminous tube therein and both ends of which are sealed; a pair of lead wires that are connected to the pair of electrodes and respectively extend outward from ends of the outer tube in a longitudinal direction of the discharge lamp body; and a metal band that is mounted on an outer periphery of the outer tube, an arc tube support plug including: a plug body having a hollow, inner cylindrical section that is formed inside the plug body and that opens at a front end; a support portion that is mounted on a front-end edge of the inner cylindrical section and supports the arc tube by holding the metal band; and a flange for mounting a reflector, and a lead support wire extending outside the outer tube in the longitudinal direction and connecting one of the pair of lead wires with the arc tube support plug, wherein a front-end face at the front-end edge of the inner cylindrical section is substantially flush with a front-end face of the flange or is positioned on a back-end side with respect to the front-end face of the flange; an angle that is formed by a straight line passing through a luminescent center of the luminous tube of the arc tube and a front-end edge of the metal band of the arc tube and a straight line passing through the luminescent center of the luminous tube of the arc tube and perpendicular to a central axis of the luminous tube of the arc tube falls within a range from 60° to 75°.