Patent ID: 6515423
Filing Date: 2003-02-04
Classification: H01J

Abstract:
A high-pressure discharge lamp comprising:a quartz glass lamp vessel (1) closed in a gastight manner and having a wall (2) surrounding a discharge space (3); a filling comprising mercury and metal-halides in the discharge space (3); an anode (4) and a cathode (5) disposed in the discharge space (3), defining a discharge path (6), spaced apart by an electrode distance D, and connected to current feed-throughs (7, 8) which extend from the discharge space (3) through the wall (2) of the lamp vessel (1) to the exterior, the anode (4) having a tip (9) with a blunt end surface S; a lamp current I through the discharge path (6) of the lamp, the lamp current I being defined as: I=P/V â€ƒwherein P is the nominal power of the lamp in watts and V is the lamp-voltage in volts; a power gap ratio PGR, being defined as: PGR=P/D â€ƒwherein P is the nominal power of the lamp in watts and D is the electrode distance D in mm, characterized in that the end surface area S in mm2 and the lamp current I in amperes satisfy a relationship according to which 0.09&lE;S/I&lE;0.16, with 3.5&lE;I&lE;8.0 amperes; the filling comprises an amount of mercury of between 65 and 125 mg/cm3; the electrode distance D is between 1 and 2 mm; and the PGR is at least 120 W/mm.