Abstract: A high pressure discharge lamp which achieves a long life of at least 3000 hours and in which variations in lamp characteristics are suppressed is disclosed. In the high pressure discharge lamp of the present invention, during manufacturing of an electrode, a covering member 123 having a coil shape and being made of refractory metal is applied on a discharge side end of an electrode rod 122 made of refractory metal so as to cover a circumference of the electrode rod 122 in a vicinity of the discharge side end. The discharge side end 124 on which the covering member 123 is applied is fused into a semi-sphere by intermittently heat fusing the discharge side end according, for instance, to arc discharge or laser irradiation.

Abstract: A lamp with a reflector in which a lamp is fixed firmly inside a reflector by fixing the lamp inside the reflector without using an adhesive. The lamp with a reflector includes a lamp having a base at one end and a reflector including, at one end of its reflecting surface, a hole into which the base of the lamp is inserted and an opening portion at the other end. The base is maintained in the hole, so that the lamp is positioned inside the reflector. The lamp is fixed inside the reflector by fitting a hollow metal fitting into the hole, inserting the base into the hollow metal fitting, and then combining the base and the hollow metal fitting into one component by welding. The position of the lamp inside the reflector can be adjusted easily and no process for drying an adhesive is required.

Abstract: A short-arc high pressure discharge lamp with a shorter distance between electrodes than a conventional lamp that realizes a long life of at least 3000 hours and suppresses the arc jump phenomenon is disclosed. In the high pressure discharge lamp, an electrode tip 124 is transformed into a semi-sphere by fusing and processing an electrode rod 122 and a coil 123 wound around an end of the electrode rod 122. A thickness “de” and a diameter “&phgr;e” of the semi-sphere are each set in a range predetermined in correspondence with a power input (W) of the short-arc high pressure discharge lamp.

Abstract: A short-arc high pressure discharge lamp with a shorter distance between electrodes than a conventional lamp that realizes a long life of at least 3000 hours and suppresses the arc jump phenomenon is disclosed. In the high pressure discharge lamp, an electrode tip 124 is transformed into a semi-sphere by fusing and processing an electrode rod 122 and a coil 123 wound around an end of the electrode rod 122. A thickness “de” and a diameter “Øe” of the semi-sphere are each set in a range predetermined in correspondence with a power input (W) of the short-arc high pressure discharge lamp.

Abstract: A high pressure discharge lamp which achieves a long life of at least 3000 hours and in which variations in lamp characteristics are suppressed is disclosed. In the high pressure discharge lamp of the present invention, during manufacturing of an electrode, a covering member 123 having a coil shape and being made of refractory metal is applied on a discharge side end of an electrode rod 122 made of refractory metal so as to cover a circumference of the electrode rod 122 in a vicinity of the discharge side end. The discharge side end 124 on which the covering member 123 is applied is fused into a semi-sphere by intermittently heat fusing the discharge side end according, for instance, to arc discharge or laser irradiation.